Recent Trends in Manufacturing and Materials Towards Industry 4.0

In this study, the austenitic grain size in bead-on-plate heat-affected zone (HAZ) are predicted as grain size has been widely known as an important factor affecting the deformation mechanism of materials, its microstructures and mechanical properties. At the first stage, a numerical model of bead-on-plate process using Goldak’s double ellipsoid heat source model is used to assess the temperature distribution during and after welding of austenitic stainless steel SS316L filler wire and plate. The numerical computation is conducted based on temperature-dependant materials properties using commercial FEM software MSC Marc/Mentat with user subroutine. Further, a numerical model is developed by using ordinary differential equation (ODE) for calculating the free grain growth algorithm combined with the presence of growing precipitates. The initial grain size (D0) value was obtained from optical microscopy observation while other values such as modified kinetic constant (M0) and activation energy (Qa) are defined through experimental investigation with various temperature ranges and holding times. It can be concluded that the austenite grain growth prediction algorithm during the bead-on-plate welding thermal cycle was successfully executed. As the outcome, grain sizes were predicted and compared with experimental investigation.

The importance of the multi-criteria decision-making field is reflected by the high number of related researches mainly in the last decade. Even though, this field still has challenges that require attention from researchers in future studies. Most of multi-criteria decision-making studies either have not considered determining decision maker’s weights or applied subjective methods to derive these weights. Also, the absence of implementing sensitivity analysis to the decision maker’s weights is noticed. Furthermore, there is a need to develop new methods that utilizing the web or mobile technologies to deal with complexity and uncertainty adhered to multi-criteria decision-making problems. This paper represents the methodology to conduct a research that aims to combine two methods (IFS-TOPSIS-exponential based and Variable Weight Theory) in a new technique that tackles the abovementioned gaps by following induction research approach to validate the new technique by utilizing the secondary data, then to use interviews to develop the mobile application algorithm to perform solving MCDM problems virtually.

Since a demands of sustainability practice implementation, the growing countries especially Malaysia using the sustainability tools to comply sustainable development goals. For the SMEs Malaysia industry, it is essential to develop a suitable sustainable assessment tool as a linking gap between the governor and the practitioner. Thus, this research will deal with a new development of the tool for assessing sustainability management in the context of Malaysian industry as a medium to assess the sustainability practices of project compliances performance. This method will use the integration of Industrial practices for a new cluster rating that refer to ISO standards and UN SDG policy as a guideline to quantify the sustainability compliances of the industry. This assessment will help the industry especially the policy-maker to measure the critical element of sustainability compliance. Hence the conceptual framework of this research is a guide mechanism for the development tool which acts as sustainability indicator that will simplify the assessment of the sustainable performance for decision making and attitudinal.

The emergence of Malaysia, the world's leading palm oil producer, has driven the industry to thrive as never before. Recently, there are few issues happen in this plantation which are difficult to observe the establishment of time equation to interpret deviation of activities, the rate establishment do not precisely illustrate the correlation between supplied resources and practical capacity, and the manager do not have a tool to monitor the unused capacity. The aim of this work is to measure the unused capacity for mature and immature area at nursery for a better accuracy. Time-driven activity-based costing (TDABC) is applied as time efficiency can be calculated effectively, idle capacity accurately defined and used and unused capacity individually listed. It also provides more comprehensive understanding of practical resources and its associated costs while measuring processes and encouraging quality improvement. This work considers a data in 2017 to develop the solution. This work found that in pre nursery, the unused capacity of time in mature and immature are −324,174 min and −221,160 min respectively while the unused capacity of allocated cost in mature and immature are RM-145878.30 and RM-75194.40 respectively. Meanwhile, in main nursery, the unused capacity of time in mature and immature are −793 min and 15,385.5 min respectively while the unused capacity of allocated cost in mature and immature are RM-428.22 and RM6154.20 respectively.

The aim of the future Computer Numerical Control (CNC) system is to be intelligent, adaptable, open, and flexible. However, the current data interface model (ISO 6983) is found to be not capable enough to meet the future challenges because of various limitations. Therefore, the new data interface model STEP-NC (Standard for The Exchange of Product Data-Numerical Control) has been developed. This new data interface model has an inherent capability to fulfill the requirements of the future CNC system. In this paper, the limitations of the current data interface model, the development of the STEP-NC data interface model, along with its benefits for the future CNC system, are discussed. The paper also presents the implementation methods of the STEP-NC data interface model, and conclude with the future direction of the research.

Various problems related to vehicle routing problem attract interest of researchers and industry. Specific optimization model and algorithm were developed to solve the problem. This intensive effort aims to reduce logistics costs and number of vehicle usage. In this context, most articles focus on different optimization method approaches. Asymmetric vehicle routing problem (AVRP) appeared when the const of delivering and returning route using the same path were difference. It was used in practical applications to solve AVRP problems identified for specific application. This paper used a well-known metaheuristic optimization method, Particle Swarm Optimization (PSO) for solving AVRP models. To optimize AVRP, three optimization objectives were recommended; the total travelling time, efficiency of the route and the number of vehicles. This is to optimize the number of targets visited. The performance of PSO is evaluated by comparing its results with other popular metaheuristics. The computational experiment was conducted using five test problems with different sizes. The optimization results indicated that this algorithm able to offer good solutions with the best answer for the practical problem. Finally, this study shows that the algorithm can significantly reduce travel costs via number of bus needed to serve all the stop points.

Numerical investigation is conducted to study the thermal performance of a double layer microchannel heat sink (DLMCHS) with the feature of interrupted flow in the bottom layer. The bottom layer has two transverse microchambers in which staggered triangular ribs are added to provide flow disruption. The width of the triangular ribs was varied to understand the effects of fluid flow and heat transfer. The thermal performance of the DLMCHS is evaluated relative to the plain non-interrupted DLMCHS using a dimensionless ratios of average Nusselt number. It is found that the heat transfer rate can be increased with the larger width of front triangular ribs as well as larger width of back triangular ribs, potentially yielding up to 41% enhancement relative to the plain non-interrupted MCHS. The results show that the staggered arrangement of triangular ribs in microchamber can be designed to play a role to divert and converge the flow to achieve better mixing in addition to the advantage of higher heat transfer surface area.

Continuous productivity improvements strongly influence human performance in the workforce. One of the key barriers to increasing productivity is the comfort that workers feel while at work. Workers are continually working on the same workload by standing up for a long time in their regular activities. The workers will felt the risk of muscular injury when the activities are related to ergonomics. In order to identify issues related to ergonomic, a specific study was conducted at JKL Company, which is a four-wheel-drive automotive product manufacturer based in Malaysia. There are four stages of manufacturing processes in JKL; namely Body shop, Painting shop, Assembly and Final shop. Out of these four processes, the assembly process uses 95% workforce in the manual process. This study used the Nordic Body Map (NBM) method to identify work complaints experienced by 51 workers during the assembly process. Based from the worker's answer, a score of “64” was obtained, which means the risk of muscle injury in the “Medium” category. Workers complained most about the limbs, especially in the neck, shoulders, arms, hands, back, waist, foot and ankle. In this case, the proper ergonomic condition is required to minimize the muscle injury experienced by the worker during the work process.

The incorporation of carbon and nitrogen elements concurrently during low-temperature gas diffusion process on the austenitic stainless steel surface leads to the formation of S phase layer. However, findings on the characterization studies of gas diffusion hybrid S phase layer are still unprecedented. This study examines the effect of treatment time on the S phase layer forming behavior of AISI 316LVM (ASTM F138) stainless steel through low-temperature hybrid gas diffusion process. The hybrid heat treatment process performed at 475 °C, with the gas composition of N2, CH4 and NH3 at 10%, 10% and 80% respectively. The variation of treatment time tested from 3 to 18 h. The outcome demonstrates the treatment time proportionally influence the expanded layer thickness. However, when the duration of treatment exceeds 15 h, the surface quality of the S phase layer decreases due to the possible high residual stress that causes the layer to crack. There are no traces of chromium precipitates at 18 h of treatment time which indicates the duration of heat treatment does not influence the formation of the precipitate. Thus, the treatment time plays significant roles in the development of the hybrid S phase layer other than heat treatment temperature and gas composition for the hybrid gas diffusion process.

The electrification of remote areas is an acute challenge globally, especially in emerging countries where it is more stringent, and Bangladesh is not any exception. Most of the country's remote regions lack grid supply, which obstructs not only the development of these regions but also the country's overall economic growth. This paper's objective is to design an off-grid hybrid energy system for a distant area to meet the daily load demand at the lowest possible cost. For the convenience of analysis and collection of datasets, Bandarban, Bangladesh, has been considered. The load details and available resources of the projected area are studied during the research. An optimization software HOMER assesses overall investigation. The outcome shows that a hybrid system consisting of PV, biomass, battery, and hydro is the most efficient system for the research area. The lowest COE of 0.128 $/kWh, NPC of $301,210, and CO2 emission of 17.6 kg/year are obtained from the results. And lastly, the outcomes are compared with other studies for validation. The analysis is performed to minimize the emission and upturn the effectiveness of the hybrid system with a relatively reduced cost.

The inspiring working demand in surface finish product of manufacturing process will step up the world into the next level. This situation will drive its effect on product appearance, function and reliability. The objective of this study is to improve a better understanding of the effects of cutting parameters such as speed, feed and axial depth of cut on the surface roughness and to build up a response surface methodology (RSM) model. An attempt has been made to achieve finest cutting conditions with respect to center line average roughness (Ra) measured in the current study with the help of response optimization technique. The design of experiment (DOE) has been used to carry out the modelling and analysis of the influence of process variables on that method. Analysis of variance (ANOVA) has been done to verify the fit and competence of the established a mathematical model. Based on the model, feed rate is the most significant value that influence the surface roughness value in milling Titanium alloy (Ti6–Al–4V).

Malaysia once has been cited by The United Nations as the best example in the world in terms of justification for the labeling of halal food. In effort to enhance productivity and the quality of the product, the organization must go through efficient methods of production by elimination of unnecessary procedures and process that add to the production cost. This paper proposes Green Lean TQM Islamic Supplier/Organization/Customer Management System and the probability to integrate these management systems in a new Islamic model that can be proposed its implementation in the Malaysian food industry. The system integrated the Supplier/Organization/Customer Management Practices of Lean Manufacturing (LM), Total Quality Management (TQM), Environmental Management System (EMS) and Islamic Manufacturing Practices’ (IMP) principles. The designation of the questionnaire was based on the adaptation of Malaysian Prime Minister Award Model, Malcolm Baldrige National Quality Award, European Quality Foundation Award, Toyota Production System, ISO16949, SAEJ4001 and MAJAICO Lean Production System. 30 selected food companies from Selangor have been participated in the survey. The reliability of the questionnaire and the data was tested and analyzed both by using Minitab Statistical Software (Minitab 17). Overall, there are 13 practices proposed in this framework. Four practices in Level 1, three practices in Level 2, five practices in Level 3 and a single practice in Level 4. Each level is determined based on the percentage of the implementation of the Supplier/Organize/Customer management practices. It is found out that for food industry, the readiness of the integrated system is still not as strong as the automotive industry with high implementation of prompt and effective handling of their customer complaint/feedback as well as practicing high assurance of continuously improved qualities.

Malaysia is one of the few developing countries rich in natural resources and it aims to achieve a high renewable energy penetration by the end of 2030. Malaysia’s energy sectors are rapidly evolving due to increasing energy demand in the country. Therefore, the use and development of renewable energy should be emphasized, not only to reduce its dependence on fossil fuel resources, but also to reduce the impact of fossil fuels on climate change. This study aims to comprehensively review renewable energy resources and non-renewable energy resources that can be utilised at least possible costs. Malaysia currently relies heavily on fossil fuels such as natural gas, coal and crude oil for its energy production. This paper explores the energy sector in Malaysia in broad terms, and particularly examines the diversification of its energy production to achieve a least cost configuration. The roles of renewable energy and nuclear energies as alternatives to close the gap of depleting fossil fuels and growing energy demands to improve energy supply security in fuel diversification are also explored using system dynamics to provide a clear understanding of the least cost option for an optimum energy penetration for Malaysia.

Malaysia is currently a net exporter of fossil energy in the form of crude oil and refined petroleum contributing to the country’s economic development but not placing sufficient emphasis on its long-term environmental sustainability. The shortage of energy scenario can be a potent threat towards the economy as it will force prudent energy usage in different sectors. This will slow down economic growth and affect consumer market. This paper aims to investigate the impact of energy shortage on the dimensional indicators of Malaysia’s energy security (ES) that has been analyzed in three dimensions: energy availability, socio-economic and environmental sustainability. The shortage of energy by 30% is a hypothetical scenario designed to replicate how this will impact Malaysia’s overall energy security by discussing the dimensions of ES and its effects. A system dynamics approach is utilized to quantify this impact for a span of 5 years from 2015 to 2020 to analyze its effects on Malaysia’s ES. Findings showed that an increase in energy shortage by 30% will greatly increase energy costs, thus impairing its affordability. As a result, the energy consumption hits the lowest limit set by the simulation suggesting an energy insufficiency to fulfill the demands of all sectors. Energy shortage will lead to an economic growth deficit but will instill an awareness to be energy-prudent, hence increasing energy efficiency amongst user groups, which can be a positive impact.

In this study, graphene oxide (GO) and carbon fibre (CF) reinforced epoxy hybrid composite has been fabricated by vacuum resin infusion method and the influence of GO reinforcement on the tensile and flexural properties has been investigated. Three different concentration of GO 0.2, 0.4 and 0.6 wt% were used to develop hybrid composite samples. The results show that both the tensile and flexural strength increase once GO is added to the epoxy-CF composite. Among the three different concentration of GO, 0.4 wt% GO reinforced hybrid composite exhibits superior mechanical properties and can be considered as the optimum value in augmenting the mechanical performance of the hybrid composite.

As the Industry 4.0 moves further developed, the manufacturing industry becomes more complex which leads to increase in complexity of daily task for operators at the same time to be highly flexible and to be able to adapt to a very dynamic working environment. There is a need in Industry 4.0 for self-improvement in manufacturing sector thus, the use of Augmented Reality (AR) can be the key to enable operator to improve the transfer of information from digital to physical world faster and more efficient. Therefore, AR application was developed for assisting users to operate novel system of UTHM Open CNC Controller (UOCC) for PROLIGHT 1000 Milling CNC machine from Light Intelitek efficiently. This paper focusses on case study of the use of AR mobile application (UOCC AR) through both qualitative and quantitative analysis to evaluate effectiveness of the application and the users’ experience, respectively. The case study covers for both experience and non-experienced users to analyze the affect AR has on machining time and users’ experience approval. The use of UOCC AR shows significantly reduce in time taken for machine operation and high in users’ satisfaction.

There are several methods to produce Graphene oxide from carbon or the oxidation of graphite such as Staudenmaier’s method, Hoffman’s method, Tour’s method and Hummer’s method. But most of the method has some limitation in term of time production, complicated, toxic and risk of self-ignition or explosion. Hummers method has been popular and great choice to synthesis graphene oxide. Commonly, graphene was produced from graphite powder using chemical vapour deposition (CVD) or Hummer’s method, but the cost of graphite is a bit high. Waste tyres in Malaysia are neither categorized as solid waste or hazardous waste. It consist of many element like carbon, wire and also polymer. Waste carbon tyre was used as a carbon source for synthesis graphene oxide in this study. Graphene oxide is widely used in many applications and give a lot of advantages for semiconductors industry. In this study, graphene oxide was synthesized from recycle carbon of waste tyre using modified Hummer’s method. The morphology and structural properties of the graphene oxide were investigated using Raman spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). Raman analysis was confirmed that graphene oxide was successfully synthesized from waste carbon tyre. It was confirmed the peaks shows that D band and G band was at 1361 and 1596 cm−1 with the intensity ratio of the D band relative to the G band (ID/IG) is 0.88. The formation of few sheets of grapheme oxide that stalked together on the surface of the sample structure, bumping pieces and coarse surface was confirmed by scanning electron microscopy (SEM). The elemental composition of carbon (C) is 50.90% and oxygen (O) is 49.10% which showed a good composition for graphene oxide. All the results were confirmed that the graphene oxide successfully synthesized from recycle carbon from waste tyre using modified Hummer’s.

Resurfacing Hip Arthroplasty (RHA) is one of the solutions for young adults with hip osteoarthritis disease (OA). Despite the positive outcomes that were achieved after RHA, the method also has its risks and complications. Early bone failure might occur as consequences from the insertion of improper implant placement. In this study, an inhomogeneous material model of femoral bone was developed from CT-based images and reconstructed to represent resurfacing hip arthroplasty. Different placement of implant was assigned to investigate the effects of the placement to the bone adaptation. Comparison of the Drucker-Prager equivalent stress between the femur bone models with the presence of implant in varus and valgus was analyzed, hence to understand the possibility of bone failures after arthroplasty. A RHA implant was assigned with material properties of cobalt-chromium. The finite element study was simulating the condition of normal walking, with the loading magnitude applied was based on the patient’s body weight. The RHA implant placement is found to have a notable influence to the bone conditions especially on the varus +18° placement with stress increment up to 36.31% in the lateral region of the femur, also 31.61 and 19.34% in the medial region of the femur. Thus, the femoral bone models implanted in varus placement shows a higher possibility of bone failures in all conditions.

The identification of natural frequency of machinery is a very important phase during the design, fabrication and testing process of any mechanical systems. This paper represents the experimental methodology for quick determining of natural frequency of a system by means of impact test. In this test, two kinds of sensors are used for the test, namely accelerometer and loadcell. The former is installed directly on the tested machine while the latter is built-in the hammer. Acquired signal from these sensors are analyzed and performed the Fast Fourier Transform (FFT) algorithm to get the transfer function. Then the natural frequencies of the system can be estimated. Besides, the corresponding coherences are also evaluated in order to evaluate accuracy of the results. This methodology is quite simple, less time consuming and very reliable for the natural frequency calculation.

This paper discussed on the performance of new end mill geometry design in terms of cutting force and cutting temperature when machining NAK80 pre-hardened steel. An experimental test was conducted using 10 mm six flute carbide end mill, coated with TiSi under dry condition. It was found that design 2 and design 3 tools recorded the highest cutting force of 489.06 N and 544.39 N at the cutting speed of 50 m/min and 100 m/min, respectively. The same trend was also observed for cutting temperature, whereby, design 2 and design 3 recorded the highest cutting temperature of 366 and 660 °C at the cutting speed of 50 and 100 m/min, respectively. Overall, design 5 outperformed other design by reducing the cutting force and cutting temperature.

In this study, measurement of effective penetration (EP), average penetration (AP) and maximum penetration (MP) of phenol-formaldehyde adhesive into Male bamboo (Dendrocalamus strictus) at various moisture content condition and evaluation of the effect of direction and section of the bamboo culm were carried out. The experiment was carried out at moisture content range between 4 and 12%, at the tangential and radial direction and nodes and internodes. The mean effective (7.9–20.6 µm), mean average (62.12–93.26 µm) and mean maximum penetration (80.41–122.51 µm) of phenol-formaldehyde was not significantly different when compared at a various level of moisture content and different direction of Male bamboo. Nevertheless, there is a significant different of adhesive effective penetration at a different section of Male bamboo.

Classified in smart material, Nitinol is also well known as a material with low formability. Welding is one of the process need to be studied to obtain good quality product by minimizing the material properties changes. The welding process could be more difficult when the material to be weld does not from the same grade or material composition. In this study, welding Nitinol from different grade was attempted using Nd:YAG pulsed laser under various laser power, pulse rate and laser scanning locations. The welding performance of different grade Nitinol alloy using Nd:YAG pulsed laser was experimentally evaluated. It is confirmed that higher pulse repetition rate and welding scanning speed is better to reduce intermetallic layer and welded area oxidation problem. Based on the microstructure and welding beads appearance, welding Nitinol alloy NiTi-SS and NiTi-02 with thickness 0.5 mm can be successfully done using Nd:YAG pulsed laser with spot diameter 0.7 mm, average laser power 150 W, pulse repetition rate 100 Hz, pulse duration 1 ms and welding scanning speed 700 mm/min.

This paper aims to investigate the effects of circular cutout and hybridization to the failure behavior of Graphite Epoxy and Kevlar Epoxy composite laminates under uniaxial tension. The composite laminates made of Graphite Epoxy, Kevlar Epoxy and their hybridizations were modelled using commercially available finite element analysis software, ANSYS APDL. The laminates were modelled without and with circular cutout. Using the available built-in failure criteria function, the failure loads for all cases were determined for various angles of fiber orientation. The laminate was having the lamination scheme of [θ4/04/−θ4]s and failure at every increment of 10° angle, where θ, ranges from 0 to 90° were analyzed. Numerical validations were also carried out prior to the failure analysis. It is obvious that the cutout significantly weaken the laminates but it is interesting to observe that arranging fiber angles 45–90° could slightly improve the laminates, compared to smaller fiber angles. In contrary, the hybridization does not have significant effect on failure behavior of Graphite Epoxy and Kevlar Epoxy composite laminates, nevertheless it provides options to balance between strength and material costs. In all cases, the generated failure curves suggested that the failure behavior of composite laminates is very much dependent on the angles of fiber orientation. In terms of the effect of cutout, it is found that the cutout reduced the strength of the laminates significantly compared to the laminates without cutout. Nevertheless, there is slight improvement of strength when the fiber angle, θ, is arranged between 20 and 90°. The findings prove that the current study is useful and this knowledge could be expanded in designing composite laminates.

The main aim of this study is to produce the improved topology of a solar car monocoque in order to reduce its weight. Therefore, this paper analyzes these 3rd generation solar car (Tigris) monocoque structural integrity, cost and power consumption. Finite element analyses were performed to simulate the deformation and generate the stress contour of the solar car monocoque. Cost and power consumption were calculated using theoretical methods. Finally, the results from the current study are compared to the previous solar cars (Stingray and Tuah). Prior to that, mesh convergence analysis and numerical validation were performed. In terms of reducing weight, the results show that the strength of the current monocoque is comparable to the previous monocoques, even it used less materials and parts. The study also suggests that the cost of fabrication of the current monocoque can be reduced up to 27% while the power consumption can be reduced up to 28%. Due to the generated data and deduced findings, it can be concluded that the current study is useful and has contributed knowledge about designing and analyzing the structural integrity, cost and power consumption of a solar car monocoque.

Renewable resources of lubricant are dominating the metalworking industry applications since chemical modification of vegetable-based oil enhanced the tribological properties of the bio-based lubricant. Nevertheless, refinement of lubricant on physiochemical quality is insufficient to inhibit friction and wear, thus additives are acquired to enhance the based-oil features. This study was aimed to evaluate the surface morphology properties induced by the friction from tribology test of modified RBD palm oil (MRPO) mixed with bamboo activated carbon (ACB) as an additive. In this work, the concentration of bamboo activated carbon is varied at 0.05 and 0.1 wt%. Four ball test was conducted to measure the tribological characteristics of lubricant samples. The steel/steel contact surfaces were analyzed using several type of analytical techniques; optical microscope, and profilometer. Results appointed that MRPO have good surface protection due to the chemical modification of triesters. However, MRPO + 0.05% ACB shown better improvement on wear and friction, due to bonding of triester with proper ratio of additives. Tribology analysis revealed that steel/steel contacts cause worst worn scars and frictional force on MRPO + 0.1% ACB. Surface morphology analyses described an excellent performance of MRPO and MRPO + 0.05% ACB. Predominantly, MRPO with mass concentration of 0.05 wt% ACB contributed to the improvement of morphology structure of sliding contact surfaces which complementary to sustainable lubrication.

Membrane Distillation (MD) system has been widely used for desalination for past decades to produce potable water for human cinsumption. However, current MD systems are fully dependent on electrical power supply for operation. In this work, a Parabolic Solar Thermal Collector (PSTC) integrated with Direct Contact Membrane Distillation (DCMD) system was designed to study the influence of a PSTC towards membrane performance. The objective of this w is to analyze the performance of the hybrid PSTC system with DCMD system in purifying seawater. PSTC was used as a support system to pre-heat seawater until the it reaches a certain temperature. In this project, as the temperature of seawater in the pre-heated tank reaches 45 °C, a 12 V submersible water pump will be automatically switched on and channel the seawater in the pre-heated tank into the feed tank of the DCMD system. In terms of energy consumption, less amount of energy is required to channel the seawater sample into the feed tank. In regards of system performance analysis, the hybrid system was compared to a DCMD system which utilises an electrical heater. It was noticed that only a marginal reduction in terms of permeate flux (7.1% difference) and salt rejection (0.8% difference) was observed when using the PSTC system. As a conclusion, the utilization of solar technology via a PSTC can potentially bring a lot of benefits in the desalination industry and in the future of employing MD system in the industry.

Solid-state direct recycling by hot press forging of aluminium scrap provide significant environmental benefit in contrast with melting technique by avoiding metal loses and high-energy saving. This work investigates the effect on microstructure and mechanical properties of recycled AA7075 alloy by hot press forging under several operating temperatures (Ts = 430, 480, and 530 °C) and holding time (ts = 0, 60 and 120 min). The best microstructure and mechanical properties of recycled aluminium chips exhibited at Ts = 530 °C and ts = 120 min. In result, the grain diameter of recycled chips to be smaller and the ultimate tensile strength (UTS) is 247.8 MPa. The mechanical properties of recycled chips are comparable with theoretical AA7075 T1-temper where maximum UTS value greater than the theoretical value. The grain size decrease and the UTS increase with the increasing operating temperature and holding time. This technique is proven as a sustainable recycling-based practice for aluminium recycling.

Cutting tool prone to rapid failure when machining Inconel 718. Apart from that, without proper selection of geometrical features of end mill significantly affects the machining performance. Therefore, the objective of this study is to evaluate the effect of helix angle and pitch angle on the machinability of Inconel 718 in terms of cutting force, temperature, surface roughness and tool life. It was found that T2 tends to reduced cutting temperature, cutting force, and surface roughness by 3.79%, 2.01%, and 48.93% respectively when compared with T1. T2 outperformed T1 due to the presence of differential pitch angle and helix angle.

Transportation sector responsible for quarter of total CO2 emissions to the environment, where CO2 is one of Green House Gases (GHG). A reduction of CO2 emissions from transportation could reduce GHG to atmosphere significantly. One way to achieve this is by reducing the fuel consumption of vehicle with implementation of light weight material in vehicle body. One of vehicle body component which have potential to implement light weight material is car fender. Car fender weight could cut significantly to 44% by changing the fender material from mild steel to polymer. A comparative analysis has been performed with two different type of materials which is mild steel (SCGA270D, TSG3109G) and polymer (Polyphenylene Oxide) in order to quantify and compare the environmental impact for both materials. The LCA data are collected using Simapro 8.0.4 software based on Ecoinvent v3.1 database. The car fender made of steel material resulted lower environment impact compared to polymer fender. Steel fender also had lower value of midpoint and endpoint impact categories compared polymer fender.

Inconel 718 requires proper cooling and lubrication due to its low thermal conductivity and high specific heat capacity at cutting area. In addition, proper selection of cutting tool geometry also contributes an impact to its performance. Therefore, the objective of this study is to compare the performance of minimum quantity lubricant (MQL) with flood cooling and also compare two types of end mill geometry when end milling of Inconel 718 in terms of cutting force and tool life. From the results, MQL condition shows the effectiveness of lubrication to cut Inconel 718 compared to flood coolant. The results of tool wear and cutting force shows significant improvement of MQL compared to flood coolant. In conclusion, MQL proved to provide enough lubrication on cutting zone while T2 was the best tools due to its geometrical features.

Inconel 718 is a difficult-to-machine alloy due to its low thermal conductivity and high strength at wide temperature range which will cause heat buildup at cutting zone. Several types of cooling techniques have been found. Hence, the aim of this study is to compare different tool design T1 and T2 with different tool geometries and study its effect on the cutting temperature, cutting force, tool life and surface roughness when end milling Inconel 718 under MQL cooling environment. The result showed that cutting tool T2 have lower cutting temperature, cutting force and surface roughness, as well as higher tool life. In conclusion, T2 is better than T1 in terms of machining performance and surface integrity because it has both unequal helix and pitch angles that stabilize the cutting tool during end milling operation.

This research deals with the influences of material model on deformation which is induced by Wire Arc Additive Manufacturing (WAAM) process simulated by means of thermo-mechanical non-linear FEM method. The feedstock material model is based on stainless steel SS316L which stems from three different sources namely existing database, initial and deposited wire. The actual feedstock materials were analyzed using SEM–EDX and modelled using JMATPRO software. MSC Marc/Mentat is used as the numerical computation software to develop WAAM model and to carryout simulation analysis. The plasticity model of each material is taken based on the isotropic hardening rule with von-mises yield criteria. The strain rate is selected within the range of 0.01–1.0 s−1 and Goldak’s double ellipsoid is chosen as heat source model. Simplified rectangular bead shape as meshed model is developed to avoid the huge pre-processing effort as well as to reduce the computational time. The transient temperature distribution is performed as means of thermal analysis on all three simulation models prior to investigating the deformation result of the WAAM component. Based on the result of the simulation, the noticeable difference can be examined by the transient temperature distribution and substrate distortion. The substrate distortion analysis shows that the distortion pattern based on real SS316L filler wire has more distortion compared to WAAM with default library database of SS316L. By using material model based on database of SS316L, the substrate distortion and transient temperature distribution are lower compared to other models.

Mangosteen (Garcinia Mangostana L.) or also known as ‘Queen of Fruits’ that consumed fresh within tropical regions possess many health benefits. The peels reported to have better content at natural phenolic antioxidant such as phenolic acids and flavonoid. However, mangosteen peels considered as a waste and discarded due to high consumption of fruit’s edible part. The aim of this study is to determine the optimum extraction condition of the mangosteen peel on the total phenolic content (TPC) and total flavonoid content (TFC) using ethanol extraction. Response surface methodology (RSM) was used to determine the effect of the two extraction variables: extraction temperature (20–60 ℃) and extraction time (30–80 min) on yield of total phenolic content and total flavonoid content of the mangosteen peel. The best condition for TPC and TFC of mangosteen peel extracts were chosen based on the desirability obtained by using extraction temperature of 50 ℃ and extraction time of 59 min, resulted in 11.27 mg GAE/g of total phenolic content and 7.78 mg QE/g of total flavonoid content. At the optimum condition, the mangosteen peel reported to have ferric reducing antioxidant power values of 137.07 mM TE/g of dry sample and 92.68% of radical scavenging activity. The flavonoid profiling and identification of catechin and rutin at optimum condition was determined by using High Performance Liquid Chromatography (HPLC). In conclusion, the extraction of time was the most significant factor for both total phenolic and flavonoid activities followed by temperature.

The purpose of this paper is to investigate the effect of age hardening conditions towards the improvement on AA7075 mechanical strength after it was put under solution heat treatment (SHT). Study was made of the effects of variable quenching mediums and aging conditions towards the mechanical properties (tensile strength and hardness) of AA7075. The work reveals that water was the best quenching medium for solution heat-treated AA7075. Age hardening was performed in various condition including natural aging (3, 7 and 14 days), one-stage age hardening (6, 12 and 24 h at 121 °C) and two-stage age hardening (25, 55, 120, 240 min at 121 °C followed by 120 min at 177 °C). Highest tensile strength of 600.2 MPa was obtained from 14 days natural aging but, the economic aspect of the conditions was shown to be inapplicable. Hence, the optimum conditions from all tested were concluded to be two-stage age hardening at a duration of 120 min with a tensile strength of 545.3 MPa and hardness of 167.43 HV. Optimum age hardening condition was identified to be at high aging duration time which resulted in higher final mechanical strength of the AA7075.

Hot stamping is a new manufacturing technology that able to produce high-strength parts by heated, formed on a hydraulic press, and subjected to rapid, controlled quenching in the closed-die. However, with the large demand for lightweight vehicles and high productivity from automotive components such as B-pillar and chassis, tooling die is a highlighted concern to be emphasized. Due to high productivity, tooling die may operate under dynamic change of temperature from heated blank and cooling channels, as well as the continuous load applied from the hydraulic press. Eventually, the die may encounter some unexpected failures, such as wear, chipping, and cracking, which probably burdened the product quality and lead time. To overcome this issue, an appropriate monitoring system is developed to track the die condition from time to time, as well as able to detect wear initiation without delay. This paper aims to review the implementation of the acoustic emission monitoring system within the hot stamping process. Also, the tool dies issues arose within the hot stamping process over the years have discussed and summarized thoroughly, as well as the wear mechanisms that occurred within tooling dies also been going through.

Leaf springs are a special kind of springs and are one of the most important components of an automobile suspension system. Leaves are actually made as a combination of series of flat plates which have semi elliptical shape. Generally, a multi-leaf spring used in automobile suspension consists of two types of leaves i.e. graduated-length leaves and full-length leaves. Leaf spring can be not only guided along a definite path but also be used as an energy absorber. This functionality can’t be found in helical spring. Leaf spring basically absorbs the vibration caused by the bumps in road. It also supports vertical load. It is subjected to millions of load cycles leading to fatigue failure. The static analysis determines the safe stress and strain of the leaf spring and also to study the behavior of structures under practical conditions. Our present study attempts to analyze the safe load of the leaf spring. It also validates the concept of cantilever beam employed in the theoretical analysis of multi-leaf spring. A lot of research work has been carried out in the context of leaf spring considering its material and significant progress has been observed in the field of weight reduction, and improvement of load-carrying capacity under the replacement with any advanced material. Finite element analysis has been carried out to determine safe stresses and payloads. The multi-leaf spring was modeled in SOLIDWORKS 2015 and the same were analyzed under similar conditions using ANSYS Workbench 19.2 software considering structural steel and SAE 1074 spring steel as the spring material. Theoretical and software-based results are presented and compared for validation. Dimensions are taken from the multi-leaf spring used in the vehicles in Bangladesh.

Recent studies have reported the advantages of cryogenic machining in producing superior surface roughness (Ra) when applied in metal cutting. This study shows the application of Box-Behnken Response Surface Methodology (RSM) to analyze the effect of milling parameters; cutting speed, feed rate, axial depth of cut (DOC) and radial DOC on the Ra of Inconel 718 when machined at high speed using PVD carbide coated ball nose inserts. The experimental work was conducted under cryogenic condition using a new cryogenic CO2 cooling system for efficient and consistent cooling at the cutting area. Experimental results revealed that the Ra was in the range of 0.114 to 0.197 μm, which far surpassed the calculated ideal Ra (0.28–0.78 μm) or that achieved by the manual polishing process (≈0.5 μm). Based on ANOVA, the dominant factor affecting Ra was cutting speed followed by axial DOC and interaction between cutting speed and feed rate. Meanwhile, the effect of radial DOC was relatively insignificant. By applying the quadratic model generated, the average error between the predicted and the experimental Ra was found to be 3.44%. Thus, the mathematical model is valid and acceptable to be used as a prediction model in this scope of study. This study also proves the effectiveness of cryogenic cutting using CO2 to produce better surface finished.

Graphene oxide (GO) is a novel class of 2D nanoscale material with remarkable properties such as excellent hydrophilic nature, higher aspect ratio and larger internal strength which results in the overall improvement of nanocomposite performance once uniform dispersion is achieved. Ultrasonication (tip based) has emerged as an efficient approach for uniform dispersion of GO solution. This study aims to identify an appropriate range of GO concentration which is of higher quality, higher aspect ratio and lower structural defects for performance enhancement of cement composites. Raman spectroscopy technique has been adopted to find an appropriate range of GO concentration (0.01, 0.0275, 0.045, 0.0625, 0.0963 and 0.125 mg/mL) on the basis of defect ratio evolved under the effect of tip sonication parameter. Results imply that the defect ratio is higher for 0.01 GO concentration as compared to others. Furthermore, an ultrasonication duration of 10 min for GO solution produces better results as quantified by Raman analysis.

Lubricant derived from Tamanu (Calophyllum-Inophyllum) fruits is a non-edible vegetable-based oil that is renewable, biodegradable and sustainable which could be added into the biolubricants products as feedstock for industrial application. The physicochemical properties of the crude Tamanu oil (CTO) including rheological, temperature and corrosion characteristics were determined for suitability as base stock for lubricant production through comparison between the RBD palm olein (RBD-PO) and crude Jatropha oil (CJO). The lubricants underwent a series of analyses on their properties in terms of physical and chemical characteristics. The density, viscosity, flashpoint, water content, corrosion test, and acid value are measured following the ASTM standards. A four-ball wear test that was subjected to the CTO was conducted to determine its lubrication behavior for friction and wear resistance. Results have shown that the CJO has a better viscosity index compared to the CTO, whereas the CTO is better than the CJO in other measured properties. The properties of the Tamanu oil need to be improved except for its flash point and corrosion inhibition properties.

With the rapid advancement of microprocessor speed and performance, the requirement for effective microprocessor cooling becomes prominent to maintain the processor optimum performance and integrity. This study investigates laminar heat transfer performance of a novel electronic liquid cooling with phase change material as thermal capacitor by adopting computational fluid dynamics approach. Two cooling channel designs are evaluated, i.e. parallel and serpentine channels with phase change material. The effect of phase change material and cooling channel configuration will be investigated. In addition, the effect of channel inlet Reynolds number is evaluated for liquid cooling channel with and without phase change material. The result indicates that the additional phase change material in a cooling channel does offer superior cooling performance, indicated by the lower average temperature than that without PCM. Consistent with other studies, convective heat transfer is increased with increasing Reynolds number. On the channel design, the serpentine channel offers better heat transfer performance with the penalty of higher pressure drop and thus higher pumping power than parallel channel.

Coating is widely used mainly to prevent from corrosion and enhance the physical and aesthetics properties. The study was conducted to characterize the surface properties of cobalt-nickel-iron (CoNiFe) alloy coating on mild steel. The coating was produced using the electrodeposition method. The electrodeposition method was carried out for 30 min with a current of 3.0 A. The average thickness of the alloy coating was 169 μm. CoNiFe coated mild steel resulted in a hardness value of 142.98 HV. Lower surface roughness was obtained for CoNiFe coated mild steel as compared to the uncoated mild steel. Slurry erosion wear test recorded a mass loss of only 0.1407 g. It can be concluded that deposited CoNiFe alloy coating could enhance the capabilities and surface performance of mild steel for various engineering applications.

Despite the productive use of the Web as a communication medium, recent research suggests that very few work has been done to leverage this new technology for enabling changes in the work environment ergonomics risk assessment process. This paper, motivated by a situation at a vehicle component manufacturer that lack of expertise, describes the integration of Knowledge-based system (KBS), analytic hierarchy process (AHP), and Web-based system for the management of workplace ergonomics, which are being increasingly applied in the industry. Lack of awareness and lack of expertise were barriers to workplace ergonomics improvements. Moreover, the need for industrial know-how experts and ergonomists to recognize the ergonomics risks in the workplace is high. In this study, twenty-six risk sub-factors have been identified for workplace ergonomics assessment and divided into four main factors individual, organizational, physical, and psychosocial ergonomics. A systematic approach to evaluating workplace ergonomics risk has been developed using the analytical hierarchy process, which enables the combination of tangible and intangible criteria and checking the consistency of decision-making. In this paper, we describe how a Web-based ergonomics assessment system (W-BEAS) can enable the standardization of the process of assessing and prioritizing the critical risk factors. Besides, W-BEAS supports participatory ergonomics intervention and functionally dispersed decision-making roles, thereby displaying characteristics of a collective decision support system. The approach has been implemented in the actual web-based system in a local vehicle manufacturer.

The need of cleaning automotive paint without secondary pollution has recently become a major concern globally. The waterjet technology has extended its application to include surface treatment, machining, cleaning and cutting of materials. Plain waterjet is frequently used for cleaning since its offers environmentally friendly concept which results near zero pollution to the surroundings. This research aims to analyse and optimise the use of multiple passes in waterjet cleaning process for removal of automotive paint using response surface method (RSM). The effect of surface roughness (Ra) and its topography were analysed. RSM, analysis of variance (ANOVA), fractional factorial at two levels were utilized to optimize the plain waterjet process parameters for effective cleaning of paint. It was found that the lateral feed and pressure were the most significant control factors in influencing the cleaning performance criteria. Mathematical model was developed using linear regression analysis to predict the surface roughness in terms of cleaning parameters of plain waterjet process. The model had successfully predicted the Ra of the plain waterjet cleaned automotive parts within the limit of this study. The recommended optimal parametric combinations for better Ra were found to be waterjet pressure of 34.0 MPa, traverse rate of 500 mm/min, standoff distance of 10 mm, number of passes of 1 and lateral feed of 0.6 mm.

The stairlift is equipment that transports a person (especially the elderly and the disabled) when going up and down the stairs both residential buildings and transportation infrastructure facilities such as stations, terminals, and airports by sitting in a chair or standing on the platform. The objective of this study is to analyze the strength of guide rails based on the guide rails profile. The material used for guide rails is ASTM A36 steel. The material profile of the stairlift guide rails is IWF 100 × 50 × 4 × 3 mm reinforced with square steel 10 × 10 mm and U Channel 50 × 30 × 3 mm. The evaluation of the strength of the stairlift guide rails refers to ASME A18.1 and ASME A17.1 standard. The acceptance criteria for the equivalent von mises stress on the guide rails is 100 MPa and the acceptance criteria for the deflection of the stairlift guide rails is 6 mm. The methodologies used in this study are a literature study, design, simulation, and analysis. The stairlift guide rails with the IWF profile needs strengthening, modification of the support shape and support distance. The stairlift guide rails with U-Channel profiles in analysis calculation and simulation meets ASME A18.1 standard requirements. The deflection of the stairlift guide rails with IWF profile and U-Channel profile in analysis calculation and simulation meets ASME A18.1 standards.

Mechanical pretreatment methods are the first steps imposed on biomass feedstocks for the production of various types of biofuels. The goal of this review article is to provide information on the varying mechanical pretreatment methods for instance mechanical-physical, combined-mechanical, thermal–mechanical and irradiation-mechanical pretreatments, pertaining to particle size reduction. Included in this short review is the grindability index as well as various types of biomass feedstock for biofuel production. Biomass grindability index $${(GI}_{VUK})$$ ( G I VUK ) , defined as the grinding efficiency in milling technique (comminution), is scarcely reported for various mechanical pretreatment methods particularly for biofuels. Thus, it is crucially needed to be promoted. $${GI}_{VUK}$$ GI VUK which is calculated based on mass, fine particle fractions and energy requirements is presented. The $${GI}_{VUK}$$ GI VUK based on mass (IE) is higher than that based on volume (IEv) and work index (Iw), indicating the importance of particle size reductions. Lastly, in this review, variety of biomass feedstocks available for biofuel production undergoing mechanical pretreatment is presented.

Surface texturing has been applied to diverse mechanical mechanisms to improve performances in various fields related to friction, lubrication and resistance to wear. The present study investigates the application of mask in producing circular craters during the abrasive waterjet surface texturing of stainless steel. In the experiment, the mask with parallel slots was placed above the surface of the specimen and the waterjet nozzle moved along the mask. The effect of feedrate was studied in terms of crater characteristics produced. The results showed that with increasing traverse rate a shallower crater depth was produced. Increasing the traverse rate also produced a narrower circular crater with improved inner surface roughness. It can be concluded that a proper selection of parameters can produce a shallow and small circular crater during the waterjet surface texturing process.

Product service system (PSS) rises surprising opportunities and purposes for companies and customers, it is in demand a set of products and services capable of fulfilling a customer’s need. Companies and customers play an important role in development from traditional product-based business model to PSS, focusing specifically on the manufacturing sector industry. Based on a traditional marketing perspective, the nation of PSS originates from the shift of marketing focus from products to a more complex combination of products and services supporting production and consumption. The primary aim of positivity can be attained if the production line system is designed, based on system use, to avoid waste and if services are developed with products. This research describes how process flow in the production line and how inventory control related to PSS based on the generated result by simulation software. PSS and inventory control have did not match together. From manufacturing industry perspectives, there is not a standard approach to implement PSS for inventory control. Inventory control in PSS creates a more extensive set of uncertainties that the factory needs to manage due to the enhanced scope and complexity of the product and service offering. The research is carried out by using the Delmia QUEST model simulation to develop visual documentation based on the production line process. Results are generated by QUEST conclude that the difference in the result obtained shows that the failure and non- failure condition in the production line affected the data inventory control concerning PSS.

Drilling process is commonly used in the aerospace industry to mount fasteners. In some cases, the drilling process is combined together with countersinking (CSK) process using a single drill bit. Improper setup of this process affects the quality of holes, thus deteriorating the process capability. Therefore, the objective of this study is to investigate an appropriate technique to improve CSK diameter repeatability and process capability. CSK drilling with seating-point outperformed without the seating point with regards to its process repeatability. Seating-point underneath the CFRP plate tends to minimize the deflection thus improve CSK diameter repeatability.

The new era of industrial revolution 4.0, requires a lot of improvement especially in automotive assembly line. A poor flow on supply chain especially on logistic in the company affect the company performance. Insufficient planning may lead to less efficiency, quality and productivity loss. The objective of this study is to improve the critical supply chain in the automotive industry by studying the current data given by the company and used it to simulate on WITNESS. The output from the current simulation will determine on how to improve the supply chain by doing some changes in which lead to the optimized condition. After series of simulations, the output shows improvement especially on idle time and busy time. The idle time that possessed was under 20% while the busy time between 70% until 90% across the mechanical and trim sections.

Child passenger safety in road traffic accident is a growing issue around the world. Malaysia has just enacted the law of using child restraint system (CRS), thus it is crucial to determine level of knowledge and awareness among Malaysian driver’s and their practice of using CRS. A cross sectional survey was conducted among parent drivers of children aged 0–10 years old at selected shopping mall and daycare center in Malaysia to assess their CRS awareness and practice. The survey was distributed among 320 parents of age between 21 and 59 years old. Initially, Mann-Whitney U test were used to compare awareness score with CRS use. Later, logistic regression analysis was conducted to analyze the comparison of CRS use with age, education level and total knowledge score. 45.6% respondents practice the use of CRS for their children and the nonparametric test of two independent samples showed a significant relationship among the respondents’ CRS awareness level towards its usage. In addition, logistic regression showed significant relationship on CRS use towards parents’ age, education and awareness level. The results show that the use of CRS is higher as compared to previous roadside observation and parents’ age and education level are significantly correlated with the use or CRS. This study will further helps in the needs of developing injury prevention interventions focusing on disseminating information on the advantages and the disadvantages of using CRS while at the same time encouraging the use of CRS.

Yttria stabilized zirconia alumina composite and calcium fluoride (CaF2) added zirconia-alumina composite (ZTA) are synthesized by using co-precipitation process. Aim of the work is to introduce calcium fluoride as a solid lubricant into the zirconia toughened alumina base matrix and study of mechanical and tribological behavior of both the composites. The homogenous elemental distribution of the required elements in the synthesized powder is shown by FESEM images. It has been found that the calcium fluoride added matrix composite shows better co-efficient of friction as compared to the base matrix. The CoF value reduces up to 28.57% with the incorporation of solid lubricant i.e. CaF2. Due to better mechanical properties of the base matrix composite, wear rate of the base matrix is lower than the calcium fluoride added ZTA sample.

In the machining process, heat generation and saturation on the cutting zone due to friction is one of the root causes of premature tool failure during dry cutting of hard-to-machine aerospace materials. Measuring and predicting thermal distribution is challenging because the tool and the workpiece are always in contact during the machining process. In this research, Finite Element Analysis (FEA) was employed to model the thermal distribution of titanium (Ti-6Al-4V), Inconel 718, and steel (AISI4340) during the machining process using three different tools: tungsten carbide, High-Speed Steel (HSS) and sintered silicon carbide. Johnson-Cook strength model and Johnson-Cook failure model were applied during the simulation using Lagrangian formulation in dry cutting. Different machining parameters i.e. cutting speed ranging from 90 to 360 m/min, depth of cut ranging from 0.5 to 2.5 mm, and rake angle ranging from 3 to 20°, were simulated and analysed. Small depth of cut of below 1 mm, low cutting speeds below 90 m/min and large rake angles above 10° are recommended for the dry cutting of these three materials to minimize the heat saturation on the cutting zone. This research provides an understanding of the relationship between material properties and heat saturation in the cutting zone for different materials. The analysis helps in the selection of predictor variables for modelling online temperature prediction using machine learning methods.

Nowadays, biomedical, aerospace, electronics, and military industries have high demand for miniaturized components due to their rapid technology development on high precision devices. Micro milling process is one of the processes that is expected to be able to produce micro-size 3-dimensional features onto workpiece. This process can be considered as costly and difficult due to dimensional effect and low cutting energy generated. It can be considered that one of its crucial components in the process is the micro size tool itself. The study challenges the capability of low cost micro milling tool during machining aluminum alloy 6065 and AISI 1045 steel material, where a 1.0 mm end mill tungsten carbide (WC) tool is chosen. The experiment is conducted using a different combination of machining condition. The surface roughness of the workpiece and size of wear length is measured using a 3D measurement laser microscope. It can be observed that the wear length increases proportionally with cutting length, resulting to the increment of the surface roughness. Machining process of higher strength material tends to wear the tool faster, shortening the life of the tool, although the machining process is possible. It is assumed that a proper selection of machining parameter is required to reduce tool wear rate and promotes a longer tool life.

In reality, copper has many potential applications, especially in thermal management but due to heavyweight, many researchers came out with a solution to reduce the weight but at the same time maintain the good properties of copper and porous copper is one of the good alternatives for this issue. Porous copper is an ideal heat transfer medium because it has high thermal conductivity that can be used as a heat sink. In this study, a material with low density and weight than dense copper with a good thermal conductivity behavior was fabricated using copper and sodium chloride (NaCl) feedstock. The volume fraction for this study is 100% Cu, 80% Cu, 70% Cu and 60% and the fabrication process to produce porous copper which covered powder blending, powder characteristic analysis, hot compaction process, debinding process and lastly sintering process. The effect of varying NaCl shows that the thermal conductivity of the sample is inversely proportional from space holder percentage and percentage of porosity,ε. the porosity achieved was 11.06% up to 27.96% for 4 different formulations of copper and NaCl. From the experiment, the highest value of thermal conductivity is 100% copper which is 363.99 W/mK and the lowest is 128.99 W/mK for the 60% copper with 40% sodium chloride. Overall, porous copper that has porosity below than 30% is suitable for heat sink applications that usually have range of thermal conductivity around 166–400 W/mK for copper alloy. So, it can concluded that the best formulation with optimum porosity and thermal conductivity that suitable for heat sink application is 80% Cu with 20% NaCl that have 283.957 W/mK for thermal conductivity and 24.49% for porosity level.

Palm oil fuel ash (POFA) was considered as a one of waste product in oil palm industry whereas the abundant of that waste contributed to environmental effects. Strong interest in the development of renewable products to reduce the environmental effects was focus on used the waste source as reinforcements in polymer matrix composites. In 3D Printing Fused Deposition Modeling (FDM), composite filament material was started used for patterns development application. However, in FDM pattern development, composite filament have common issue especially on nozzle clogging problem that relate to the critical process in composition mixing and filament preparation. Therefore, this research is aimed to investigate the capability of different percentage composition in range 20–60 vt.% of POFA with polypropylene (PP) materials to be formed into solid composite filament for FDM machine. The composite material was mixed well used brabender mixer machine and added 5 and 8 vt.% maleic anhydride grafted polypropylene (MAPP) as compatibilizer to improve the bonding ability of the PP matrix and POFA. The Melt Flow Index (MFI) test was conducted on all POFA-PP composition to investigate the data of viscosity which important for filament extrusion process. The single screw extrusion machine was used to form a composite filament with diameter and length range 1.70–1.80 mm and 60–70 cm respectively. The observation result of POFA filament deposition test on FDM showed that 40 vt.% POFA, 55 vt.% PP and 5 vt.% MAPP was the best composition of filament and give the best deposition result of printed the ISO527-1 (dog bone sample).

This research focuses on investigating major imperfection in coupled processes of ““Welding-to-Forming”” and “Forming-to-Welding” which are frequently found in parts production in automotive industries. Finite Element Method (FEM) based Virtual Manufacturing (VM) approach is used to predict final dimensional change in both welding and forming processes through the utilization of specialized FEM software Simufact.Welding and Simufact.Forming. This research is to demonstrate the accuracy in predicting final geometry in both coupled processes where the physical properties from the first process serves as the initial condition for the later process. Low carbon steel S235 with thickness of 2 mm along with filler material ER70s mild steel is selected as material for both coupled process simulations. This study incorporates thermo-mechanical FEM as the solver for computational process as well as assign Goldak’s Double Ellipsoid Heat Source model on welding simulation that serves as moving heat source, while in forming process, a sheet metal bending process with hydraulic press is incorporated. For each coupled process, the result of the first manufacturing process will be transferred with legitimate procedure proposed by Simufact software and will serve as the initial condition for the subsequent manufacturing process. The FEM-based VM simulation was successfully conducted for both coupled process and shows in simulation result, that the average final displacement due to spring-back effect on coupled processes of “Welding-to-Forming” is 1.52 mm, while on “Forming-to-Welding” simulation results, the average final distortion yields the value of 1.12 mm.

Nickel oxide (NiO) nanosheet (NS) array films were successfully grown via a simple immersion technique on the seedless and seed-coated glass substrates. The NiO NS on the seed-coated glass substrate (SC) and the NiO NS on the seedless glass substrate (SL) were annealed at 300 °C. X-ray diffraction pattern revealed the crystallinity of SC film improved. This SC sample also had small crystallite size. The crystal parameters based on (200) plane, such as dislocation density, interplanar spacing, lattice parameter, unit cell volume, strain, and stress were calculated for both samples. Most notably, the dislocation density increased for SC film. The surface morphologies were characterized by field emission scanning electron microscopy and disclosed the porous NS structures. The cross-sectional images exposed that the thickness of the NS array was thicker for SC sample due to the presence of a seed layer. The ultraviolet-visible spectroscopy measurement spectra of the SL and SC films exhibited low transparencies with the average values taken in the wavelength between 400–800 nm were 25.9% and 13.8%, respectively. The optical bandgap energy values of the SL and SC films were 3.64 eV and 3.61 eV, respectively. The current-voltage measurement results show that both films exhibited ohmic behaviour with the SC film has lower resistance and resistivity, and higher conductivity than the SL film. Based on these findings, both films can be benefited in sensor applications due to the porous film structure and good conductivity characteristics.

Continuing improvement in the field of virtual crack closure technique of metals provides the opportunity for reliable probabilistic fatigue crack growth. The paper presents an analysis of mode I fatigue crack growth in low carbon steel. Experiment was carried out with Single Edge Notched Tension (SENT) specimens to determine its fatigue crack growth parameters on the specimens under constant amplitude loading. Linear elastic fracture mechanic crack path was modelled with the finite element method according to its experimental observation using the virtual crack closure technique (VCCT) in MSC Marc/Mentat. The simulation predicts the fatigue crack growth rate in high cycle fatigue. The simulated fatigue crack growth rate (FCGR) produced using SENT model represents good similar feature with the experimental process at stress ratio R = 0 Based on the remeshing model, it is also found that the results of crack growth rate and cycle count show good agreement within acceptable discrepancy compared to the experiment from Paris law diagram.

This paper presents the application of inherent strain method (ISM) for predicting distortion on selective laser melting (SLM) specimens using general purposed finite element method (FEM) software. Since the prediction distortion might acquire extensive computational time, direct analytical approach is applied as an alternative to other method such as thermo-mechanical method. The procedure will start with the estimation of initial inherent strain value based on process parameters and material properties of austenitic stainless steel SS316L as well as the effective area. The selected SLM parameters are laser power, beam spot diameter and efficiency, along with material properties. It is to be expected, that the simulation outcome of simplified geometry with general purposed numerical software, MSC Marc/Mentat 2019 will exhibit acceptable estimation compared to specialized additive manufacturing software.

Hot embossing of glass micro structures requires long thermal cycle, generally takes no less than 15 min due to the isothermal heating, pressing and cooling performed inside a closed vacuum chamber. In this paper, a new hot embossing procedure was presented. First, the glass was preheated slightly below its glass transition temperature at the heating station. Then, a thin layer of the glass surface was further raised to high temperature temporarily through CO2 laser irradiation. The glass was then quickly transferred to the embossing station for pattern transfer, demolding and followed by external cooling. This method accelerated the filling of glass material into the microlens array mold cavities and outperforms the conventional method in terms of overall cycle time reduction, lower mold working temperature and embossing pressure. Microlens array with diameter of 135 µm, sag height of 18.5 µm and pitch of 200 µm were faithfully embossed onto the K-PG375 optical glass time in a time scale of about ~3 s. Optical evaluation of the glass MLA was also performed using charge couple device (CCD) camera which showed uniform spot intensity.

Titanium dioxide (TiO2) nanotube arrays (NTAs) material have received attention due to their high stability in optoelectronic devices. As-prepared TiO2 nanotubes layers are amorphous and their properties are not sufficient enough to applied in device applications. The TiO2 NTAs was synthesized by electrochemical anodization method. The medium was mixed to facilitate the growth of TiO2 NTAs and annealed to improve the anatase structure. The field emission scanning electron microscopy (FESEM) images revealed the prepared TiO2 NTAs grow uniformly with average diameter 50.82 nm (450 °C) and 68.17 nm (as-prepared sample). The Raman spectroscopy reported the annealing temperature is critical issue to determine the crystallinity and structure of TiO2. The X-ray diffraction pattern showed the TiO2 NTAs exhibit anatase phase with prominent (101) diffraction peak that was recorded for the sample annealed at 450 °C. The band gap value (3.21 eV) was obtained for the sample annealed at 450 °C due to homogeneity of the TiO2 NTAs structures. This approach is cost-effective in synthesizing high quality ordered of TiO2 NTAs for optoelectronic applications.

The concerns and awareness towards environmental benefits have brought the scope of development on composites materials from textile waste fiber (cotton fiber) and polymer matrix (epoxy resins) as an approach to recycle, reduce and reuse practices for high scale of textile fiber waste. This research study was conducted to investigate the effects of silane fiber treatment on tensile and impact properties. The composite specimens were fabricated using a closed compression molding technique, according to ASTM D5224-12. Physical properties such as the density were calculated according to ASTM D792-08, where the untreated specimen has the highest density value with 1.125 g/cm3 as compared to the variable treated values (1 wt% −1.069 g/cm3, 3 wt% and 5 wt% −1.067 g/cm3). The stress-strain parameters in this study were also attained through tensile test ASTM D3039 standards showing that untreated specimens had the highest tensile strength and tensile modulus with 11.02 MPa and 1.38 GPa, respectively as compared to other silane treated composite specimens. Besides, low-velocity drop weight impact test with a constant 10 J impact load was conducted according to ASTM D7136. All the damaged pattern specimens were inspected at macroscopic level observation. The images seen were captured using a smartphone camera model Vivo Y11. Based on the results obtained, the untreated specimens projected the highest values on tensile strength and modulus and owned maximum impact strength and initiation energy as compared to all treated fiber specimens. The reason is due to fiber strength reduction on the composite materials. Damage pattern observation examined also showed that cracking on the surface area was better on the untreated specimens.

This study presents a numerical analysis of spot-welded DP600 steel sheets to evaluate the strength of the spot-welded joint and damage model under tensile-shear loading conditions. The quality of spot-welded joint is highly dependent on process parameter, material properties and setting on the equipment. Experimental testing is commonly used method to validate the spot-weld quality, but it is costly and time consuming. The present work aims to verify the capability of FEM simulation to model the spot-welding process and generate a reliable result. The spot weld is modeled according to a standardized dimension using a non-linear FEM simulation. The main parameters used to simulate the spot-welding process are current, electrode pressure, and weld cycle. The boundary conditions were set-up in the simulation according to mechanism applied in real application and experiment. As spot weld is governed by electrical-thermal, mechanical, and metallurgical, it has been observed that the material plasticity, thermal and electrical contact conductivity are critical input in spot welding simulation. The simulation result obtained from this study is useful for future works to validate the spot-welding behavior in the FE simulation compared with experiment.

Turn signal neglects have been identified as among the main contributors to motorcycle crashes and injuries in Malaysia. To date, several prior naturalistic observational studies have been conducted to address this situation. Nevertheless, aspects including the use of turn signals for various motorcycle movements, factors contributing to such use and how the motorcycle riders initiate and cancel the turn signals were still lacking. Thus, this study was initiated to address the aforementioned gaps through in-vehicle video recordings from the perspective of a car driver, along the pre-determined routes in several locations in Selangor and Kuala Lumpur, Malaysia. Based on the 3963 observations, the multivariate logistic regression analysis revealed that female riders and those who wore helmets, carried a pillion, ingressed and egressed the expressways, turned at the 3-legged unsignalized intersections, entered the roundabouts, performed right turns, and travelled on weekdays, at dawn, dusk, night, during inclement weather, and on single carriageway, and single lanes were significantly more likely to activate their turn signals. The results also indicated that the majority of riders initiated the turn signals before crossing the line either along expressways or at intersections. Longer duration of turn signal initiation and cancellation were observed at unsignalized intersections as compared to expressways and signalized intersections. These findings necessitate either the development of new or improvement of existing technological system to increase the use of turn signals among riders.

This paper presents an investigation on deformation behaviour using elastic inherent strain method (ISM). The deformation of bead-on-plate substrate is induced by GMAW process in which the selected material of filler and substrate is austenitic stainless steel SS316L. A simplified rectangular bead geometry is modelled and the process is simulated using numerical software MSC Marc/Mentat. The inherent strain value is estimated based on process parameters and physical properties of selected material, the effective area and the structural clamping positions. The residual stress and deformation result predicted using ISM are to be compared with thermo-mechanical numerical simulation which is executed under consideration of temperature dependent isotropic hardening rule and heat source model using model Goldak’s double ellipsoid. Further, computational time between these two methods are to be compared. It can be concluded that ISM is very potential to be implemented to predict residual stress and distortion with short computational time.

Seawater batteries is a useful device for an emergency application with the utilization of the abundant and accessible resources. Most of the small scale batteries that are studied and developed using seawater electrolyte as energy source are published without the report on the materials characterization that may affect the environment quality. Thus this study is focusing on the materials characterization of the electrodes tested for seawater battery. The study performed on carbon rods as a cathode, while magnesium (Mg) and zinc (Zn) are anodes for two different combinations of electrodes for battery cell system; Mg–C and Zn–C cells respectively. The Mg–C cell was able to produce almost constant voltage output up to 8 h which is 2.53 V to power up a small torchlight as a load, while Zn–C electrodes was only 0.90 V and unable to power up the same load. Materials characterization was conducted before and after the test in seawater electrolyte for 4 and 8 h of test duration by using SEM, EDX, and ICP-MS. The results obtained from SEM–EDX analysis showed a major changes on the Mg anode only where the pure Mg (100 at.%) has changed into new phases that identified as a phase containing the mixture of Mg (reduced to less than 4 at.%) with chlorine, oxygen and calcium after the test, while Zn anode and carbon electrode for both cell showed a slight formation of new phases. Based on the ICP-MS analysis on the tested seawater electrolyte, the Mg–C electrodes is considered safe to be used as compared to Zn–C because ICP-MS has recorded zinc particles content in the tested seawater electrolyte exceeded the standard amount of Zn in natural seawater after 8 h of the test duration. Although, the Mg content in natural seawater (215 ppm) has increased about 49% (320 ppm) after the test, but the amount is still considered low for a standard Mg content in natural seawater which is 1300 ppm. The study has proved that Mg can be used as a safe anode to be applied in a battery using seawater as a renewable energy source.

This research presents an investigation of material property model effects of thick-walled Wire Arc Additive Manufacturing (WAAM) process on deformation behaviour which involves thermo-mechanical non-linear numerical computation. A 3D thermo-elastic–plastic WAAM model is developed using general purposed FEA software MSC Marc/Mentat. The material models of component stainless steel SS316L were simulated based on two different sources namely material X5Crnimo18_10_1from default library database and evolved wire. The thermo-mechanical and thermo-physical material properties of evolved wire SS316L were obtained using chemical composition analysis SEDM-EDX and generated by advanced material modelling software. Component geometry was modelled using simplified rectangular shape and mesh which consists of ten layers and three strings. The numerical simulation was implemented under consideration of temperature dependent hardening rule with von-mises yield criteria and Goldak’s double ellipsoid heat source model was utilized. Based on the adjusted thermal coefficient parameters, the transient temperature distribution between two different material property models were analysed. The outcome of this research is to characterise the substrate deformation induced by WAAM process using material models of evolved component SS316L and existing material from default library database.

The railway maintenance industry has been using welding process to repair the damage on the rail head surface due to its constant and continuous friction with train wheels. Hardfacing is one of the adaptable methods that can build up the hard and wear resistant surface layer on the surface of substrate material. In this work, the UIC-54 rail head surface was grinded and welded with three layers by using HF-350 flux-cored wire with 90% argon, 10% CO2 shielding gas under 245A current and 23 V voltage. The deposit specimen and it surrounds have been examined to determine its structure and mechanical properties. Results show that the base microstructure consists of broad ferrite and pearlite structures while for weld area with acicular ferrite structures. Hardness result show improved hardness properties for base to weld metal from 381 to 437 HV. The tensile results show the deposited layer have the highest Ultimate Tensile Strength (UTS), 1162 MPa compared to HAZ and base metal. The fracture mode was assessed by SEM indicates the ductile characterizations that contained micro voids and dimples on fractured surface. The obtained results exhibit superior properties of repaired welded layers, due to the change of microstructure from original pearlite structure in base metal to the acicular ferrite structure in welded layer in relation to mechanical properties results.

A child safety seat is usually installed on a motorcycle when the rider needs to travel along with a small child. However, limited products can be found in Indonesia where motorcycle is the most popular transportation mode. The main objective of this paper is to propose a safe and comfortable child seat design, then perform theoretical strength analyses to evaluate its safety factor. The proposed child safety seat is designed for children under five years old with average weight of 24.2 kg and height of 70–100 cm and is targeted for Honda Vario Techno 150 scooter. The seat is installed on the rear part of the motorcycle, and equipped with a hinge mechanism, hence the rider can refill the gasoline tank by flipping the seat up. Theoretical calculation of safety factors under static and dynamic (fatigue) loading conditions was conducted by two failure criteria, i.e. the Modified Goodman and Gerber. As a result, the fatigue safety factors for Modified Goodman and Gerber criteria are 1.05 and 1.02, respectively. These results imply that the proposed design is reliable and can be considered for real application. In addition, this paper demonstrates a comprehensive machine design procedure which can be referred as a lecture note in mechanical engineering.

The main objective of this paper is to develop an analytical method based on the energy balance equation to model the plastic deformation of thin metallic tubes in a high velocity forming process under axisymmetric conditions. A yield criterion is proposed, which involves the coupled effect of the axial and circumferential internal force resultants. Using a combination of power-law strain hardening and strain rate hardening flow stress models, both strain hardening and strain rate effects are included. The proposed method permits consideration of the influence of different terms of kinetic energy and plastic work of the tube. The study presents a typical electromagnetic tube expansion model, using a dynamic high strain-rate forming method with strain-rates above 103 s−1. In this process, the deformation of the workpiece is achieved by the interaction of a current generated in the workpiece with a magnetic field generated by a coil adjacent to the workpiece. The results reveal that the achieved high strain rates influence the plastic flow stress and the final permanent radial deformation, consequently. The study concluded that an appropriate shape function eventuates a more accurate estimation of both the radial displacement and the deformed meridian profile.

Cellulose nanofibers (CNFs) are linear polymer that exhibits high stiffness and strength due to extensive intermolecular and intramolecular hydrogen bonds among the molecules. These nano materials are taking place in replacing synthetic fiber as reinforcement in nanocomposites. This present work investigates the potential used of CNFs in improving microstructural and mechanical properties of thermoplastic polyurethane (TPU) nanocomposite. Cellulose nanofibers used in this work was extracted from jute fiber via chemomechanical method. Neat TPU and TPU/jute CNFs nanocomposite were successfully prepared by using melt blending method. In addition, the morphology and mechanical properties of prepared net TPU and TPU/jute CNFs nanocomposite were evaluated through field emission scanning electron microscope (FESEM), shore durometer and vickers micro hardness. FESEM micrograph reveals that the jute CNFs exhibited a uniformly dispersed in TPU matrix. The incorporation of jute CNFs result in increases of 20.13% hardness strength of prepared nanocomposites.

Photovoltaic-thermal is a technology that converts solar energy into usable electrical and thermal energy. Many studies have been performed to increase the performance of the photovoltaic efficiency through thermal management of its surface temperature. The efficiency of PVT system is affected by many factors such as its design configuration and operating conditions. In this study, a series of simulations with concentration of 0, 0.1, 0.5, 1.0 and 1.5% wt of Al2O3-Cu were performed and the results were compare with experimental result from literature using ANSYS fluent. Simulations were performed to determine the thermal efficiency and collector efficiency of a PVT system. Based on the simulations, it is shows that at 1.5% wt of Al2O3-Cu dispersed in water based have the highest thermal efficiency of 76.91% at flow rate of 0.044 kg/s and collector efficiency significantly.

Higher Education Institution (HEI) is influential organization to thrive civil society. It perceived to underpin the growth of prosperity. It is assured to provide quality of education. Indonesia with huge numbers of HEI particularly private HEI faces the challenges of competitive in the global order. In terms of quality practices in education, service quality has been increasingly recognized in HEI context, whilst research on student satisfaction research is known as a prominent factor in HEI. Research to measure student satisfaction on service quality in Indonesian private HEI is rarely featured. Therefore, this study attempted to develop framework to measure service quality of Indonesian Private HEI from student satisfaction. The proposed framework is interpreted through Structural Equation Model (SEM). The results are expected to be used as a notion for Indonesian Private HEI to enhance the quality of service provided in the effort of quality of education.

This paper presents basic procedure on coupled design and simulation process for 3D metal printing. As case study, the selected automotive component is front upright with the proposed material of austenitic stainless steel SS316L. This component is modelled based on real application loads and constraints in order to improve driving performance. Various outcomes are created by using generative design method based on preserve and obstacle geometry, selected materials and additive manufacturing method. Preferred design outcome will undergo smoothing process using T-Spline method and be analysed to identify the weak point at the base and bionic shape. Smoothing procedure will include additional material and sharp edge removal until desired stress and safety factor are achieved. Since 3D metal printing consist of rapid high temperature gradient during printing process, the residual stress and distortion of the final component are to be identified in order to mitigate the imperfection using mechanical analysis from inherent strain direct approach method. This process simulation using numerical computation is conducted to define best build orientation. It is expected that, the coupled design and simulation procedure for 3D metal printing can contribute to lightweight and resource-efficient additive manufacturing process.

Structural integrity and high specific stiffness made wide applicability of aluminum alloys for various transport vessels in the automobile and aerospace industries. The advent of friction stir welding (FSW) is making it more realizable with the advantage of welding of dissimilar materials in solid-state. However, the lack of online defect monitoring techniques in FSW bars the wide use of it in industries. Therefore, the online assessment technique in FSW is a focal research area because of its propensity to reduce material wastage, rework time, and cost. This article reviews recent research efforts on online defect monitoring in FSW of aluminum alloys, intending to identify research gaps that need to be addressed to boost the effectiveness of the online welding process. In this study, the sensor-based monitoring approach in literature was grouped into two: a single sensor approach and the multisensory approach. It was noticed that although researchers using the single sensor detection approach recorded higher prediction accuracy, the use of multiple sensors has been demonstrated to give hope towards the development of robust detection of defects that will be able to cope with variations in material thickness and type of materials. This study further suggests the need for research efforts to focus on grey-box online monitoring techniques, sensor fusion, and cloud computing as pathways towards industrial adoption of online defect monitoring.

Apart from the functional and economic aspects, the sustainability of any manufacturing process in terms of resource consumption and production of waste has gradually evolved as one of the most important performance metrics in any industrial landscape. Now-a-days, a significant fraction of joining works in automobile and aerospace industries are carried out using friction stir welding (FSW), that make butt or lap joints of similar or dissimilar materials using frictional heat and mechanical mixing caused by a rotating and traversing non-erodible tool. Unlike fusion welding, the strength of the welding in FSW welded aluminium alloys can be very close to that of the parent materials due to the suppression of formation of oxide and voids. Energy consumption and greenhouse gas emission in FSW has been reported to be less by around 40% and 31% respectively as compared to gas metal arc welding. Feasibility of welding aluminium to other metals by FSW bears the promise of lightweight structures, and thus, may lead to improved life of the structures and higher fuel efficiency for vehicles. This paper explores the recent advances in the field of FSW that establish this process as a more sustainable green alternative to the other joining processes.

Jute fiber reinforced polymer (JFRP) is extensively used nowadays especially in the automotive, marine, aerospace because of its lightweight, high strength, and high confrontation to erosion. However, the machining of JFRP is very hard to machine, and its requirement also very high to be machined. Besides, the lack of proper quality machining technique and parameter can lead to JFRP machining as poor surface quality and delamination. Solid carbide cutting tool was used to machine JFRP composite and the diameter of the cutting tool was 8.0 mm. In this study, the effect of input variables (feed rate, depth of cut, cutting speed) was investigated to observe the surface quality of the JFRP and delamination factor by following the milling process. The designed cutting parameters of JFRP during milling operation ranging from 671.57 to 6328.41 rpm for the cutting speed, 0.79–2.21 mm range of depth of cut, and lastly feed rate from 108.51 to 391.42 mm/min. The experiment number was 15 and performed following the CCD of Response Surface Methodology. The optimum input parameters were determined during milling of JFRP and most significant factors were highlighted. On the basis of the established mathematical model, the most significant factor was determined as the feed rate that affected the surface quality and delamination. Finally, it was found that lower surface roughness and delamination factor were achieved at higher cutting speed, lower feed rate, and lower depth of cut. The optimized cutting parameter was cutting speed, feed rate, and depth of cut 4293.78 rpm, 150 mm/min, and 1 mm respectively with the surface roughness of 1.18 µm and delamination factor 1.09.

The characteristics of the interaction between the tire and the road pavement surface are one of the important aspects that must be taken into account in maintaining the safety of driving. Although the tire tread design might have a significant effect onto the contact behavior whereas various design of tire tread available in the market, there is still lacking of understanding on its relationship to tire performance. Thus, the objective of the study is to simulate tire-road contact behavior related to tire tread design utilizing Finite Element Analysis. In the study, several basic design of tire tread had been proposed, and modelled for FEM application. The simulation condition chosen was based on the domestic application, where vehicle ride by average persons was taken into consideration. It is shown that, tread design has a direct effect onto stress distribution inside the tire structure, which cause variation of deformation behavior. The stress distribution is well distributed inside tire and higher intensity 4.0 MPa can be estimated between tire and road in vertical tread designed tire compared to other chosen tire tread designed. This is due to constantly large contact area between tire and road, giving the chance for the force to be distributed inside the tire structure. The estimated stress distribution might have an affect onto tire contact performance, as higher intensity contact stress might mean higher effective contact, while large distribution might mean better stability where force is distributed nicely inside the tire structure.

Nowadays, JFRP composite is known as an eco-friendly, cost-effective, lightweight, higher stiffness product and the demand for this composite is increasing tremendously in various applications like automotive, aerospace, marine, and domestic upholstery. In order to achieve the required shape and design of this composite, machining is essential during the assembly stage. Thus, machining arises some difficulties in where the delamination factor is one of the major drawbacks during the machining of the milling process. The cutting parameter of machining influences on the output performance of the product. The main aims of this study are to find out the effect of milling parameters such as feed rate, spindle speed, depth of cut on the output response of the delamination factor which generates during milling on JFRP composite. The machining was done by using a solid carbide cutting tool of 8 mm width and the experiments were conducted according to the CCD. A mathematical model also developed in this study to correlate the milling parameters with the output parameter of the delamination factor.

Major challenges for any direct nanostructuring method on glass substrate is the difficulty to scale up the patterning area to industrial scale. In this work, a rapid and large area direct thermal imprinting of glass nanostructures using silicon mold assisted by CO2 laser irradiation was demonstrated. Pattern transfer was successful for experiment trial of one spot laser irradiation and laser scanning with imprinting area of 100 mm2 and 400 mm2; confirmed by SEM and AFM measurement. When the method was extended to a larger imprinting area (2000 mm2), the glass was cracked and partially imprinted due to the high cooling rate of the glass after laser irradiation and misalignment of the glass during the contact pressing step in our molding setup.

Spacecraft needs thermal protection systems material that rise more than ±1.260 °C on nose cap and wing leading edge. It depends on the heat loading encountered during the re-entry of the orbiter into the atmosphere. Recently, the spacecraft uses thermal protection system (TPS) materials like reinforced carbon-carbon (RCC), High-Temperature Reusable Surface Insulation (HRSI), Low-Temperature Reusable Surface Insulation (LRSI), and Felt Reusable Surface Insulation (FRSI). The TPS is an isolator material which have range temperature −121 °C until 1.649 °C. This paper analyzes Tantalum Carbide (TaC) and Hafnium Carbide (HfC) for spacecraft material. We show that Tantalum Carbide (TaC) and Hafnium Carbide (HfC) would rise above the TPS materials temperature. The comparison among RCC, HRSI, LRSI, FRSI, and TaC-HfC is on the heat resistant temperature. The TaC and HfC is heat resistant material that rise 3726.85 °C. The TaC-HfC is recommended for spacecraft using, especially on nose cap and lower surface. Nose cap and lower surface are area of spacecraft body which would experience extremely high temperatures when aircraft fly to left and entry the atmosphere.

Free-piston engine generator (FPEG) provides a novel method for electrical power generation in hybrid electric vehicle applications. This paper presents a new piston positioning method for assessing the performance of a dual-piston type FPEG. Numerical simulations were conducted to obtain motion profiles necessary for the algorithm development. A flowchart for the algorithm was produced. The new piston referencing is named cyclic position which illustrates similar crank-angle-based referencing employed for conventional crank slider engine applications. The results demonstrated cyclic position as qualitative tool for FPEG performance assessment which can be used for data-acquisition user interface in experimental investigations.

Lanthanum manganite is a material that has wave-like properties because it has a single-phase reflection loss that is suitable for microwave absorbing material application. Further improvement in reflection loss is done by substituting Fe3+ ions into the lanthanum manganite lattice structure. In this study, material engineering has been examined by substituting iron into lanthanum manganite (La0.8Ba0.2Mn1-xFexO3) for Fe3+(x = 0.1–0.7) using the solid reaction method through mechanical deformation techniques. The refinement results from the X-ray diffraction pattern indicate that the single phase is obtained for the composition x ≤ 0.3. At concentrations x > 0.3 has formed hexagonal fetite phase (BaFe12O19). Single phase formation of lanthanum manganite monoclinic structure with group space I 1 2/a 1 with lattice parameters, cell unit volume, and atomic density changing as a function of composition. Morphological observation of particles using a scanning electron microscope showed that the particle size distribution was evenly distributed for the composition of x = 0.3 with particle sizes ranging from 100–500 nm. Increased reflection loss occurs in the composition of x = 0.3 in all frequency values in X-Ku band. It is concluded that the effect of Fe substitution on the lattice structure of lanthanum manganite results in the structure parameter changing as a composition function with the best reflection loss in the composition x = 0.3.

Comparative analysis on morphological, structural, and optical between zinc oxide (ZnO) nanorods on unseeded and seeded glass substrates was estimated. Both samples were synthesized by simple solution immersion method and annealed at 500 °C for 1 h. The morphological, structural, and optical properties of the investigated ZnO nanorods were characterized using Field Emission Scanning Electron Microscopy (FESEM), X-Ray diffraction (XRD) spectroscopy, and Ultraviolet-Visible Spectroscopy (UV-vis), respectively. Average diameter size of ZnO on seeded glass substrates calculated from FESEM was 90 nm, four-fold smaller from the sample on the non-seeded layer. The wurtzite ZnO showed rod arrays morphology. It was found out that the (002) peak is the most dominant, indicating that the ZnO grows preferentially along the c-axis. No other peaks are suggesting that no impurities other than pure ZnO were obtained. The optical band gaps of seeded glass substrates ZnO nanorods decreased to 3.48 eV. High crystalline of ZnO nanorods on seeded glass substrate was achieved and can be beneficial for optoelectronics application.

Undoped ZnO and ZnO doped with various concentration of TiO2 (ZnO:TiO2) at 1, 3, 5, 7 and 9 wt% were prepared on ZnO seeded layer coated glass substrate by hydrothermal method. Based on XRD analysis, the crystallite size of ZnO:TiO2 thin film decreased when the concentration of TiO2 increase. The diffraction peak for all ZnO:TiO2 samples show the presence of dominant ZnO phase at (002) plane that refer to hexagonal wurtzite structure with c-axis orientation. For the UV-Vis analysis, ZnO:TiO2 thin film that have doped at 5 wt% of TiO2 concentration has the highest transmittance. This sample also shows the highest porosity with value of 1.3044. The the absorbance edge at UV range of ZnO:TiO2 doped at 5 wt% of TiO2 concentration has shifted towards lower wavelength which possibly the increasing of charge carrier. Therefore, it can be concluded that the properties of ZnO will change when TiO2 at different concentrations is doped into ZnO material.

In this work, graphene oxide was prepared using a modified Hummers’ method and then decorated with nickel using the hydrothermal method. FESEM images of the graphene oxide and graphene oxide-nickel oxide showed that they presented different nanoflake structures. EDX spectra confirmed that oxygen, carbon, and nickel were present in the graphene oxide—nickel oxide. XRD spectra revealed that the crystallinity of the graphene oxide decreased after nickel oxide was added to the system. FESEM images of the nanocomposite polymer showed the morphological changes when graphene oxide and nickel oxide were added to the composite structure. The conductivity results were discussed using a Nyquist plot to confirm the electrical properties of the polymer nanocomposite with the presence of a semicircle and a 45° straight line. The conductivity increased to 1.61 × 10−9 S/m when graphene oxide decorated with nickel oxide was added to the composite system.

Snap fits are the easiest, fastest and most cost-effective joint approach to assemble two parts. When properly designed, elements with snap-fits can be jointed and disjointed repeatedly without any negative impact on the attachment. Snap-fits can reduce the product’s assembly time by as much as 60%. Snap-fits need to give more attention to their engineering designs compared with mechanical fasteners. It is because if snap-fit is not designed properly, the parts may fail before or during assembly or also during the usage of the snap-fits. The work carried out intended to analyze the influence of snap-fits design parameters towards the insertion forces exhibited during the matting process. A different set of parameters are used for cantilever snap-fits type. In the analysis, ANSYS is used to imitate the assembly process of the joint and produce force data. The result indicates the influence of each parameter to the insertion force required for assembly. As conclusion, beam lengthy, beam thickness and width plays an important roles in increasing the value of force reaction during assembly.

Numerous studies have been conducted on the lightweight design of vehicle structures and components due to the stricter environment and safety regulations. There are two ways to reduce the vehicle’s weight namely optimizing the design or re-designing, and material substitution. Material substitution is one of the most promising approach in lightweight design due to cost and time consideration. This paper is looking into an optimal material selection approach for lightweight design of a vehicle component. Firstly, the design requirements for the vehicle component of study, which is car door panels are determined through literature review. The material selection of the car door panels is performed by screening of available materials, giving four material choices which are steel alloy, aluminium alloy, magnesium alloy and Carbon Fiber Reinforced Composite (CFRP). CAD model of the car door panels are designed and assembled using Solidworks software. Using the same software, a side impact test is also done for each material, using forces ranging from 775 to 3100 N, to evaluate the mechanical performance and crashworthiness of the materials. The process is followed by choosing the optimum material with the genetic algorithm (GA) based optimization in GANetXL. Magnesium alloy proves to be the optimal lightweight material without compromising the mechanical properties and cost.

Lean is a concept that eliminates all waste and maximizes customer value with fewer resources needed based on the Toyota Production System. The purpose of this study is to identify lean manufacturing practices from the literature review and industrial experts, and to develop a lean assessment tool to measure the level of lean implementation in manufacturing firms. A quantitative lean assessment approach in the form of a Likert Scale questionnaire survey with a total of 19 lean practices were developed and sent to two different electronics manufacturing firms with similar processes and product range. The high values of Cronbach’s Alpha which is more than 0.8 show that the questionnaire is reliable. The Two-Sample T-test was used to compare the level of lean implementation between the two companies as well as to compare the view of Top management and Executive position. The results of statistical analysis show that the average mean score for Hard Lean practice for Company A is 3.63 and for Company B is 3.05, while the mean score for Soft Lean Practice for Company A and Company B is 4.14 and 2.85, respectively. The level of lean implementation of Company A for both category of Lean Practices is significantly better than Company B. Therefore it can be concluded that Company A is having a better lean implementation compared to Company B. This study has implications for the firms as it can explore the extent of lean manufacturing implementation and to compare the leanness of departments within a firm. The limitations of the research were small sample size and lack of involvement from the executive level. For future study, the open-ended interview can be integrated into the research and the contents of the questionnaire can be modified based on firm types.