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Exposure of commuters to pollutants on trains has been an essential topic of discussion in recent years due to its health implications. This review summarizes literature that measures particulate matter (PM) in trains to understand the concentration levels and health effects caused due to exposure. The databases searched were Scopus, Web of Science (WOS) and Google Scholar. Articles, conference papers and textbooks written in English, measuring PM in train carriages and published between 1998 and 2022 were selected for this review. Out of the 3247 articles identified, only 73 were included in this study. 15/20 articles agreed that concentration is significant at the underground segment by a factor of 7 than the counterpart above/ground levels. The review observed that 80% of the publication of in-train concentrations of PM10 and PM2.5 were above the WHO standard. In-train PM2.5 concentration ranges from 2 μgm−3 to 563 μgm−3, and in-train PM10 concentration ranges from 6 μgm−3 to 997 μgm−3. People’s activities, mechanical movement of train parts, train operation conditions and local emissions were the primary source of PM. Future research should focus on health damage due to PM exposure and the effect of the filtration system on PM levels in trains.

Nafion based proton exchange membrane (PEM) has long been used as conventional PEM in direct methanol fuel cell (DMFC) industry. However, the high cost of Nafion membrane and other drawbacks like high methanol crossover hinder the advancement of this industry. This study aims to develop a low cost membrane using sulfonated poly ether ether ketone (SPEEK) polymer. Silica and silicotungstic acid (SiWA) were incorporated into the membrane matrix using solution casting method. The optimum loading of the additives was tuned and it is discovered that the SPEEK membrane containing 10 wt% of silica and 5 wt% of SiWA has the best performance due to its high proton conductivity and moderately low methanol permeability. The performance of the membrane can further be enhanced by adding (3-aminopropyl)triethoxysilane (APTES) and carbonyldiimidazole (CDI) as coupling agents. Inclusion of APTES and CDI in SPEEK could not only improve the compatibility between organic SPEEK and inorganic additives, but also improve the homogeneity and dispersity of the additives. As a result, the resultant membrane with a better dimensional stability achieves high selectivity (10.60 × 104 S.s/cm3) up to 6.5 times more than pristine SPEEK membrane and 1.3 times higher than the commercial Nafion 117 membrane.

The roof is the primary heat source for landed buildings since it is exposed to the sun. This will lead to significant heat gain in the attic, causing thermal discomfort for the indoor dwellers and increasing cooling loads. An ideal cool roof system plays an important role in inhibiting excessive heat gain and lowering the cooling load for attic temperature reduction. The experiment was conducted indoors by projecting two 500 W halogen spotlights at each roof model to replace the sunlight. The temperature of roof surface, attic, and moving-air-cavity (MAC) were measured using K-type thermocouples. The variation of temperature versus time for each roof model was compared against the predecessor design and base model. Significantly, with the cool roof model integrating vegetation layer, lightweight foam concrete roof tile, and active MAC with solar-powered fans, the attic temperature remained cool at 26.9 °C with a rate of 0.003 °C/min, 96.77% lower than the based model with reinforced concrete roof. The outstanding performance is due to the inventive cool roof system comprising the ability to minimize the heat gain while circulating the hot air efficiently in keeping the attic cool.

Concrete is one of the broadly used construction materials in the construction industry. This research intends to recommend the replacement of conventional coarse aggregates with recycled lightweight expanded clay aggregate (LECA) which offers several advantages such as lightweight, low cost, and easy availability. Lightweight concrete (LWC) offers numerous benefits; therefore, many researchers are using lightweight aggregate to produce lightweight structural composites concrete to compensate heavy loads by reducing the concrete self-weight due to lower density of lightweight concrete, improving in thermal properties and fire resistance, saving the cost of transportation and handling of precast units in the site. Different percentages (0, 0.15, 0.30, and 0.45%) of volume fraction of barchip polypropylene (BPP) fibre have been incorporated to improve the mechanical properties of lightweight aggregate concrete (LWA) concrete. In this study, the mixture of crushed lightweight expanded clay aggregate (CLECA) and barchip polypropylene (BPP) fibre have been used to achieve compressive strength between 28 and 37 MPa at 28-days with an oven-dry density ranged between 1900 and 2000 kg/m3. It is found that the inclusion of BPP fibres at an optimum volume fraction concrete enhances the compressive strength, splitting tensile strength and modulus of rupture. The compressive strength of the lightweight aggregate concrete containing 0.45% volume fraction of BPP fibre (CLLWAC-BPP0.45%) had achieved the highest compressive strength of 37 MPa at 28-days with a significant increment of about 31% compared to plain concrete. Hence, the findings of this research showed that the development of eco-friendly lightweight structural composites can be used as an alternative solution for conventional lightweight concrete, infrastructure and marine fields application.

The performance of a plate heat exchanger (PHE) using water as the working fluid with zigzag flow channels was optimized in the present study. The optimal operating conditions of the PHE are explored experimentally by the Taguchi method, with effectiveness as the objective function. The results are further verified by the analysis of variance (ANOVA). In addition, the zigzag flow channel geometry is optimized by the non-dominated sorting genetic algorithm-II (NSGA-II), in which the effectiveness and pressure drop of the PHE are considered the two objective functions in the multi-objective optimization process. The experimental results show that the ratio of flow rates is the most important factor affecting the effectiveness of the PHE. The optimal operating conditions are the temperatures of 95 °C and 10 °C at the inlets of hot and cold water flows, respectively, with a cold/hot flow rate ratio of 0.25. The resultant effectiveness is 0.945. Three geometric parameters of the zigzag flow channel are considered, including the entrance length, the bending angle, and the fillet radius. The sensitivity analysis of the parameters reveals that a conflict exists between the two objective functions, and multi-objective optimization is necessary for the zigzag flow channel geometry. The numerical simulations successfully obtain the Pareto optimal front for the two objective functions, which benefits the determination of the geometric design for the zigzag flow channel.

The present work analyzed the fire protection performances, char formation and heat release characteristics of the thin film intumescent fire protective coatings that incorporate the eggshell (ES) waste as a renewable flame retardant nano bio-based filler. The fire performances of the coatings were evaluated using Bunsen burner and cone calorimeter. The fire behaviors of the samples in the condensed phase were conducted in accordance with the ISO 5660-1 standard. On exposure, the samples B and D reinforced with 3.30 wt.% and 2.75 wt.% of ES nano bio-filler, respectively showed a significant reduction in total heat rate, promoting thicker and more uniform char layer in protecting the steel structural. As a result, ES nano bio-filler composition has shown to be efficient in fire protective performance of the intumescent coatings.

This study aims to investigate the performance of using a Diffuser on a horizontal wind turbine. Diffuser variation used has two different geometries : without an Inlet Shroud (L/D = 0.25) and with an Inlet Shroud (L/D = 0.39). The wind turbine’s test is performed on a wind tunnel with a low wind speed ranging from 1 m/s to 5 m/s. The results showed that with the addition of a Diffuser, the power produced shows an increased. Variation of the Diffuser without an Inlet Shroud is able to increase power efficiency up to 20.5% while the Diffuser with an Inlet Shroud can increase power efficiency up to 41.1%. This suggests that the use of a Diffuser is capable of improving the performance of the wind turbines by improving produced power efficiency.

Electric vehicle (EV) has been steadily gaining attention and as a viable alternative to mitigate pressing global energy crisis and environmental issues caused by conventional internal combustion engine vehicles. Nonetheless, the dynamic operation of EV encompassing high charging and discharging currents generated from regenerative braking and acceleration, respectively, may adversely affect the cycle life of the conventional energy storage system. Hence, incorporation of supercapacitors into the energy storage system is recommended in view of its superior cycle efficiency and high power density, which aids in relieving the battery’s stress and thus extends its cycle life. In this study, a hybrid energy storage system (HESS) comprising Li-ion batteries and supercapacitors are modeled to evaluate its electrical and thermal performances under different driving cycles. The results obtained reveal that the dynamic stress, peak power demand and thermal performance of the battery have been significantly improved by incorporating supercapacitors into the battery pack in HESS. In comparison with the conventional battery energy storage system, the peak current demands of the battery in HESS for UDDS and US06 cycles have been reduced by 63%, 72.9% and 71.7%, respectively. This approach has shown to be effective in extending the battery’s lifespan and is able to improve the safety and reliability of the conventional battery energy storage system.

Concentrated photovoltaic cell (CPV) had gained much attention recently due to high efficiency at a competitive cost. However, efficiency of CPV is inversely proportional to the temperature. Hence, it is important to reduce the maximum temperature and variation of temperature across the CPV. Metal foam with its high specific surface area, thermal conductivity and tortuous flow path to promote mixing is an ideal candidate for thermal management for CPV. However, the thermal performance of the metal foam may drop from upstream to downstream and lead to poor cooling performance near the outlet. In this study, functionally graded metal foam is attached on the CPV to extract the heat generated. Functionally graded aluminum foam with gradual variation porosity are modelled to investigate the thermal performance and flow field using computational thermal fluid dynamics analysis. Heat transfer correlation, permeability and resistance loss coefficient are extracted from the literature and used in the simulation. The results showed that functionally graded metal foam with gradual reducing porosity offered a better temperature uniformity for the CPV. Therefore, this approach will further extend the cycle life as well as improve the overall efficiency of the CPV.

Single-chamber sediment microbial fuel cells (SSMFCs) have received considerable attention nowadays because of their unique dual-functionality of power generation and enhancement of wastewater treatment performance. Thus, scaling up or upgrading SSMFCs for enhanced and efficient performance is a highly crucial task. Therefore, in order to achieve this goal, an innovative physical technique of using interface layers with four different pore sizes embedded in the middle of SSMFCs was utilized in this study. Experimental results showed that the performance of SSMFCs employing an interface layer was improved regardless of the pore size of the interface material, compared to those without such layers. The use of an interface layer resulted in a positive and significant effect on the performance of SSMFCs because of the effective prevention of oxygen diffusion from the cathode to the anode. Nevertheless, when a smaller pore size interface was utilized, better power performance and COD degradation were observed. A maximum power density of 0.032mW/m2 and COD degradation of 47.3% were obtained in the case of an interface pore size of 0.28μm. The findings in this study are of significance to promote the future practical application of SSMFCs in wastewater treatment plants.

Industrial 4.0 accelerates the need to introduce clean energy to accommodate the increase in electricity demand globally without causing environmental issues. Metal-air battery is a new type of energy storage system in which the metal anode is consumed to generate electricity through the electrochemical reaction. Among various types of the metal anode, aluminum is a promising energy carrier. Aluminum-air battery shows advantages such as high capacity, abundance, low cost, and being environmentally friendly. Traditional aqueous aluminum-air battery experiences restriction from application due to its self-corrosion issues. In this study, instead of reducing or limiting the self-corrosion issues, a different approach is proposed so to make use of the self-corrosion issues of the aluminum-air battery. By incorporating an additional hydrogen-air subcell to the aluminum-air battery, this hybrid system turned the self-corrosion issue into a beneficial reaction by utilizing the hydrogen gas produced from the aluminum anode as the fuel to power the hydrogen-air fuel cell and improving the overall power performance. The electrical performance of each system is studied experimentally using potassium hydroxide electrolytes. The hybrid system shows a great improvement as compared to a single system. The maximum power is improved by more than 40%. This study shows that the hybrid design is feasible in enhancing the aluminum-air battery performance and yet, maintaining low cost and low weight in nature.

The COVID-19 pandemic has plunged the world into uncharted territory, leaving people feeling helpless in the face of an invisible threat of unknown duration that could adversely impact the national economic growths. According to the World Health Organization (WHO), the SARS-CoV-2 spreads primarily through droplets of saliva or discharge from the mouth or nose when an infected person coughs or sneezes. However, the transmission of the SARS-CoV-2 through aerosols remains unclear. In this study, computational fluid dynamic (CFD) is used to complement the investigation of the SARS-CoV-2 transmission through aerosol. The Lagrangian particle tracking method was used to analyze the dispersion of the exhaled particles from a SARS-CoV-2-positive patient under different exhale activities and different flow rates of chilled (cooling) air supply. Air sampling of the SARS-CoV-2 patient ward was conducted for 48-h measurement intervals to collect the indoor air sample for particulate with diameter less than 2.5 μm. Then, the reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) was conducted to analyze the collected air sample. The simulation demonstrated that the aerosol transmission of the SARS-CoV-2 virus in an enclosed room (such as a hospital ward) is highly possible.

Fire-resistant board is the crucial recent development for fire safety protocol in many buildings. A fire rated board can provide valuable time for the human to evacuate during a fire outbreak. Intumescent fire protection materials provide a wide variety of passive fire protection system with the most efficient utilization. In this research project, the water-based intumescent binder was mixed with vermiculite and perlite to construct the fire-resistant board. Furthermore, the fire-resistant boards were conducted and evaluated by small-scale fire test and three-point flexural test. The best fire protection performance of fire-resistant board was selected and compared with the commercial gypsum board (GB) under the fire test. The experimental result was noticed that this novel fire-rated board (P2) incorporated with the addition of aluminium hydroxide and eggshell flame-retardant fillers in the intumescent binder formulation was consistently proven to be more effective by reducing the temperature up to 78 oC as compared to commercial gypsum board in preventing fires with respect to its sustainability and maintaining the technical integrity throughout the period of 2-h fire test. Lastly, the three-point flexural test observed that P2 reveals the highest flexural stress of 3.542 MPa and the lowest flexural modulus of 208.33 N/mm2 as compared to other fire-resistant boards by exhibiting the highest ductility characteristics.

Fire-resistant intumescent coatings applied in steel buildings are important passive fire protection measure to ensure the structural integrity of steel during fire accidents. This study highlighted the use of BioAsh as natural substitute to industrial fillers in the water-based intumescent coating. Fire-resistant properties of water based intumescent coating reinforced with different particle sizes of BioAsh were investigated via fire-resistant test (FRT), carbolite furnace test (CFT), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). GIC3 sample showed the lowest equilibrium temperature of 115.5 °C and the thickest char expansion to effectively limit the penetration of heat. GIC3 formed the densest and most compacted char layer as shown in the SEM, indicated an excellent char quality and strength to inhibit the heat propagation to the steel substrate. TGA demonstrated the highest residual weight 33.12% of GIC3 at 1000 °C. This research revealed the green intumescent coating incorporated with renewable BioAsh was a promising fire-resistant approach to protect the steel from fire.

Self-consolidating concrete (SCC) is an extensive conventional concrete technology which uses the similar constituent materials but possesses distinctive characteristic compared to conventional concrete. Self-consolidating concrete is highly deformable that can spread into every corner of formwork without any mechanical compaction. The main objective of this research is to study the effect of silica fume on the fresh and hardened properties of self-consolidating concrete in terms of slump diameter, compressive and ultrasonic pulse velocity. Different percentage of silica fume (0, 10, 15 and 20%) as the cement replacement material are incorporated in the self-consolidating concrete to produce self-consolidating concrete with a minimum compressive strength of 50 MPa at 28 days. The significant finding of this study is the implementation of new method in the mixing of concrete constituent materials. This new method resulted in 33% total reduction of time for the mixing process as compared to the conventional mixing method. Hence, this research revealed the incorporating of silica fume with new mixing method was a promising approach to achieve good compressive strength in concrete industry.

Waste Heat Recovery System (WHRS) technology, e.g., Organic Rankine Cycle (ORC) has been explored as a solution to the increase in geothermal potential, possibly applied in binary or combined form, as a single-flash plant. This approach utilizes waste brine obtained from the separator. The purpose of this study, therefore, was to determine the performance of R134a refrigerant on ORC systems, using scroll-expander. The experiment was conducted with motor different frequency, at 7.5 Hz, 10 Hz, 12.5 Hz, 15 Hz, 17.5 Hz, and 20 Hz, evaporator temperature regulation of 95 °C, condenser at 10 °C, and an initial working fluid pressure of 5 bar. The results showed modifications in the ORC system performance with scroll-expander, alongside the motor frequency, which influenced the net power and energy efficiency. In addition, the maximum speed produced by the expander was 505.8 rpm, while the highest for energy efficiency achieved from the system was 3.17%, at a motor frequency of 7.5 Hz, with a resulting net power of 584.5 Watt.

In the modern design of commercial buildings, the requirements for fire safety and evacuation must comply with to ensure the protection of human lives and property. The applications of flame-retardant materials in buildings play a vital role in reducing the risks of fire propagation. This study aims to synthesize an eco-friendly intumescent coating by incorporating the novel eggshell (ES) nano bio-filler. The samples were then characterized using Bunsen burner, thermogravimetric analysis (TGA), scanning electron microscope (SEM), Fourier transform infrared (FTIR) and pull-off adhesion tester. The coating D with an appropriate combination of the binder and flame-retardant ingredients had significantly improved the formation of char thickness in protecting the coated steel. This char layer showed a denser and more uniform foam structure surface in the SEM micrograph. Additionally, this formulation had exhibited the highest adhesion strength of 2.13 MPa, which indicated the effectiveness of interface attachment on the substrate. Moreover, the thermal stability of the formulation had also increased in thermal analysis. Therefore, the outcomes of the research revealed that uses of optimal quantity of nano bio-filler leading to better fire protective performance and mechanical properties of the intumescent coating.

Oil palm shell (OPS) is a renewable resource obtained from agricultural solid end products via the extraction of palm oil. A study on preparing the lightweight concrete (LWC) using heat-treated and...

This piece of research presents the capability of active and passive cool roof systems, which is designed to reduce the heat transmission into an attic through the metal deck roofing for industrial buildings in Malaysia. In this study, an ideal cool roof system focusing on utilizing solar energy, cavity ventilation and thermal reflective coating (TRC) were employed and investigated. This technique is one of the most innovative and sustainable practices at reducing the energy consumption that provide buildings with comfortable indoor conditions through natural means. The four cool roof models were designed and built in active and passive systems to examine the effect of attic temperature reduction. Application of TRC can significantly reduce the heat absorption of the metal roof. The roof and attic temperatures of the roof models were measured to determine the performance of cool roof system. The roof design (d) results indicate a great reduction at about 15 °C in the attic air temperature compared to normal roof. The outstanding performance is due to the cool roof system that integrated TRC, improved moving air cavity (MAC)-solar powered fans and opened attic inlet comprise the ability to reflect the sunlight and circulate the hot air efficiently.

Thermal management system is crucial for a Lithium-ion battery pack as cycle life, driving range of electric vehicle, usable capacity and safety are heavily dependent on the operating temperature. Optimum operating temperature of Lithium-ion battery pack is about 25–40 °C. Power availability of the battery pack may differ according to the operating temperature. Although air cooling is the simplest and cheapest cooling solution, the cooling capacity is still limited by the low specific heat capacity. This will cause large variation of temperature of cells across the battery pack. In this study, mist cooling is proposed for battery pack thermal management system. Experiments and numerical simulations are conducted to investigate the thermal performance of conventional dry air cooling and mist cooling. Simulation results are then validated with the experimental data. The simulation results show that mist cooling can offer lower and more uniform temperature distribution compared to dry air cooling. Mist cooling with mass flow rate of 5 gs−1 and 3% mist loading fraction is sufficient to ensure the surface temperature of the battery module maintained to below 40 °C. Therefore, mist cooling is a potential solution for the thermal management system of Lithium-ion battery pack.

Recent advancement in the micro-scale and nano-scale electronics systems, the demand of an innovative solution for the thermal management to dissipate the high amount of heat flux generated have become more rigorous to ensure good reliability of the devices. Micro-channel heat sink has been introduced to dissipate the heat flux with capacity of 10 MW m−2, which providing an ideal solution in the thermal management technology. Researches have been done experimentally or numerically to investigate effect of different geometric designs of micro-channel heat sinks to promote better heat transfer between micro-channel walls and cooling fluid. Other than micro-channel geometric design, type of cooling fluids and two-phase flow boiling are important issues in the micro-channel based thermal management system. In addition, applications of nano-fluids in the micro-channel heat sink are also highlighted which helps in improving the thermal conductivity of the coolant and leads to better heat dissipation rate. In addition, applications of micro-channel in the engineering sector such as solar cell, fuel cell and medical devices are reviewed. For the literature, implementation of micro-channel in the electronic devices as a thermal management solution is highly recommended due to its ability to protect and prolong the lifespan of electronic devices.

How to improve the performance of thermoelectric generators is an important issue to recover waste heat and convert it into green power, which is conducive to practicing net-zero carbon dioxide emissions. The heat transfer and power generation of a thermoelectric module (TEM) under the influence of fin installation is investigated by three-dimensional fully numerical simulations where vehicle exhaust waste heat is harvested. This study considers a TEM in a hot channel without fins as well as with plate fins and square pin fins, while a cold channel is used to cool the TEM. The results show that installing plate fins or square pin fins can drastically intensify waste heat harvest, and the optimal number of square pin fins is 78 which increases the output power of the TEM by 24.14% compared to the plate fins. A compromise method in terms of heat flow rate ratio and heat flow rate ratio per unit area of square pin fins is conducted, which simultaneously considers the TEM’s output power and material cost. As a result, it is found that the optimal number of square pin fins is 54. The influences of the temperature and mass flow rate of the hot fluid on TEM performance are also evaluated, and the results indicate that the former has a pronounced impact whereas the latter is relatively unimportant. Installing more square pin fins gives rise to a higher pressure drop. Nevertheless, the net output power of the TEM increases with increasing the number of square pin fins and the highest value occurs at 78.

In tropical countries, air conditioning system is commonly used to provide thermal comfort in buildings. However, operating the air-conditioning system for long hours daily will result in escalating electricity bill. Hence, an effective roof cooling system is desired to reduce the high energy cost while maintaining the thermal comfort in the buildings. In view of this, closed loop pulsating heat pipe (CLPHP) roof cooling system is introduced in this study. The thermal performances of the CLPHP roof system are investigated through a series of experiments and benchmark with the bare metal roof system design. The experiment results showed that the cool roof system with CLPHP technology can lower the attic temperature from 34 °C to 29.6 °C, with about 13% of temperature reduction as compared to the bare metal roof design. The results showed that CLPHP cool roof system is found to be a promising method for attic retrofitting interventions to improve thermal comfort in the building.

The utilization of bio-based renewable lightweight aggregates with pre-treated coating methods, using a grout binder derivative of water/cement (w/c: 1.25), is a recent development meant to enhance the performance of high strength and lightweight concrete. It aims to promote the long-term sustainability in the field of concrete technology. In this experimental analysis, coated tenera shells (CTS) and coated dura shells (CDS) acted as a replacement for tenera shells (TS) and dura shells (DS), respectively. It has previously been investigated in terms of its physical strength and associated material properties, as a lightweight bio-based aggregate concrete (LWBAC). The results revealed that through the substitution of raw TS and DS aggregates with that of CTS and CDS, the density of the samples which fell within the range of high strength lightweight concrete (HSLWC), slightly increased. As a result, the workability of the oil palm shell concrete (OPSC) showed a significant improvement by almost 41% with the use of the pre-treated OPS aggregates, as compared to the non-treated OPSC. The strength of the HSLWCs with the CDS mixture achieved the highest compressive strength and modulus of elasticity at 28-days, which were recorded at 52 MPa and 17.1 GPa, respectively. The ultrasonic pulse velocity (UPV) was also assessed, and the outcome revealed that a good condition was attained after 7 days. Therefore, pre-treated CDS and CTS has proven to be a highly recommended, eco-friendly aggregate, which serves as an alternative solution to improve the properties of OPS aggregates, and substantially enhance the performance of the LWBAC.

This paper investigates a fluidized bed boiler used in an ethanol production plant. The boiler uses biogas fuel produced by the waste system of the distillation unit within this ethanol plant. Using Engineering Equation Solver (EES), a mathematical model is developed by employing the exergy analysis. Before the study was undertaken, initial operating data of the components in the plant was collected. The results show that the boiler system has an overall efficiency of 68.238 %. The exergy efficiency in each component was also calculated. The evaporator and heat exchanger have the lowest efficiency at 45.97% and 28.96%, respectively. The efficiencies of the other components are 61.41% for the pump water pit, 54.42% for the soft water tank and 66.39% for the de-aerator.

Li-ion battery is widely used as an energy storage system in electric vehicles and it has several advantages such as long cycle life, high energy density, superior usable capacity, low self-discharge rate and fast charging capability. However, the optimum operating temperature window of the battery is limited to 25 °C - 40 °C. Actual performance can deviate substantially if it is operated at higher or lower temperatures. Although electron and ion mobility is increased at high temperature due to low internal cell resistance, It may initiate irreversible chemical reactions which can cause thermal runaway. At temperature below 0 °C, the cell’s internal resistance is high and the performance starts to deteriorate due to Lithium plating. Therefore, this highlights the importance of the thermal management system for the Li-ion battery. In this study, thermal performance of the mist cooling was studied and compared with conventional dry air cooling using computational fluid dynamic simulation. Simulation results are then validated with experimental data and the correlation between Nu and Re was derived. From this study, it is shown that mist flow rate of 0.37 gs-1 and air velocity of 2 ms-1 is sufficient to maintain the surface temperature of dummy battery below 40 °C. Hence, mist cooling can be used as a new cooling solution for the Li-ion battery.

With the rapid development of the micro-scale and nano-scale electronic systems, the requirement of the operating temperature becomes more stringent to ensure good reliability and safety. Hence, thermal management technologies for dissipating the heat generated become an important agenda for researchers over the world. Micro-channel heat sink has been widely investigated by researchers and it is known that by increasing the total heat transfer area to volume ratio could enhance overall heat transfer performance. There are various types of micro-channel available such as straight channel, pin fin and wavy channel. Straight channel is the most common used of micro-channel in the market due to ease of manufacturing and low cost. There are several drawbacks associated with the straight channel design especially cooling performance is deteriorated along the flow direction. This will lead to the development of high temperature gradient from upstream to downstream and resulted uneven cooling performance which in turn shortens the device life expectancy. In this study, a novel geometrically graded micro-channel heat sink is introduced to improve the thermal performance of the conventional straight channel heat sink. Computational fluid dynamic simulations were conducted to investigate the performance of the novel fin micro-channel and straight channel heat sink. Under heat load of 2000 W, the geometrically graded micro-channel heat sink could reduce the average temperature to 69.6 °C and variation of temperature to 2.7 °C.

Temperature is one of the factors which affect the power availability, driveability and durability of the battery pack. Folded fin and serpentine channel are commonly used to provide cooling for the battery pack. During the cooling process, fluid absorbed the heat generated along the flow direction and caused the reduction of the cooling capacity. Hence, downstream temperature is always higher than the upstream temperature. Inconsistent cooling effect will lead to high variation of temperature distribution and shorten the life expectancy of the battery pack. In this study, a battery module consists of three pieces of LiFePO4 pouch cell arranged side by side, and aluminium foam is sandwiched between two heat spreaders to form a cooling plate. Aluminium foams with different porosity and pores density were modelled to investigate the thermal performance and flow field numerically. Correlation of Nusselt number, permeability and resistance loss coefficient from the literature was extracted and used in the CFD simulation. From the simulation results, it is shown that 10 PPI aluminium foam with 0.918 porosity offered the highest thermal performance and lowest flow resistance. Hence, the optimized aluminium foam cooling plate can be used as a new type of cooling system for the battery pack.

Successful implementation of electric vehicle relies strongly on its energy storage systems. Li-ion battery is the best candidate for the energy storage systems due to its energy density, power density and low maintenance. Temperature will affect the power availability, driveability and cycle life of the battery. Hence, effective thermal management system is needed to prolong cycle life and ensure balance charging/discharging among the cell in the battery pack. In this study, a battery module comprised three pieces of Li-ion pouch cell is arranged side by side and attached to aluminum foam heat sink to extract heat generated. The performance of two different type of pores density aluminum foams with different porosity were investigated numerically. Experimental correlation of Nusselt Number, permeability and resistance loss coefficient from the literature was extracted and used in the steady state CFD simulation. Among the metal foams, 10 PPI aluminum foam with 0.918 porosity offered the highest thermal performance and lowest flow resistance. Hence, it was shown that aluminum foam can be used to replace heat sink in the battery pack.

The aim of this study is to present the performance of an innovative wind–solar-rain water hybrid renewable energy generator and harvester roof system. A novel V-shape roof guide vane (VRGV) that located above the vertical axis wind turbine (VAWT) is introduced to guide and increase the wind speed by the venturi effect before it interacts with the rotor blades, hence improve the performance of the wind turbine. 2D CFD simulations was carried out to verify the optimized effect of VRGV out of nine different angles of roof designs and to estimate the increased speed by the VRGV. From the simulations, the optimum inclination arrangement of the V-shape roof guide vane is 25°. The wind speed augmented factor of the VRGV was 44%, from 2.00 m/s to 2.88 m/s. The working concept of the VRGV is to minimize the negative torque zone of a VAWT and to reduce turbulence and rotational speed fluctuation. Besides, the design of the VRGV that blends into the building architecture can be aesthetic as well. An experimental setup has been developed to verify the effect of VRGV using a prototype. Anemometric measurements were used to calculate the power of wind turbine. The system was also designed to provide optimum surface area and orientation for solar power generation. An automatic cooling and cleaning system with a stream of rain water was designed to clean and cool the roof which can improve the electrical efficiency of the solar photovoltaic modules. The ventilation vents of the system allow warm air inside the building to be ventilated out from the building by the pressure difference. The skylighting in the system improve the living comfort level and reduce power consumption of artificial lighting.

The huge amount disposal of light expanded clay aggregate (LECA) had become a serious environmental issue across the globe which represents an immediate threat to the environment. One of the potential solutions is to incorporate these wastes into construction materials, mainly concrete. These waste materials are abundant and easily available. The addition of recycled crushed LECA creates void space in the concrete which helps in decreasing the density of concrete, and reducing the dead loads needed to be sustained for buildings. In this study, different volume fraction (0, 0.15, 0.3 and 0.45%) of macro polypropylene (MPP) fibre have been used to enhance the strength properties of lightweight concrete (LWC). The combination of lightweight LECA and MPP fibre have been used to achieve compressive strength between 25 to 40 MPa with a density ranged between 1800 to 2100 kg/m3. It is found that the addition of MPP fibres at an optimum volume fraction concrete enhances the compressive strength. Hence, the findings of this research revealed that it can be used as an alternative solution for concrete industry.

The aim of this research project was to investigate the effects of hybrid flame-retardant fillers on the fire protection and mechanical properties of solvent-borne intumescent coatings. Formulations of intumescent coatings with different combinations of flame-retardant fillers were developed and investigated through Bunsen burner test, adhesion strength test and Scanning Electron Microscopy (SEM). It was found that the formulation of intumescent coating was optimized with four combinations of flame-retardant fillers in proper compositions and had improved the fire protection performance and mechanical properties of the coating. In overall, filler compositions of coating sample D (1 wt.% nano CES/ 2 wt.% expandable graphite/ 1 wt.% zinc borate/ 4 wt.% calcium silicate) had contributed to positive fire protection performance (equilibrium temperature of 190 °C) and adhesion strength (2.62 MPa). Significantly, the incorporation of an appropriate combination of hybrid nano CES bio-filler, expandable graphite, zinc borate and calcium silicate had led to a better fire protection performance and mechanical properties of the solvent-borne intumescent coating.

A technical feasibility study of an innovative hybrid solar-wind-rain eco-roof system with natural ventilation and skylight for electrical energy generation and saving is presented in this paper. The system integrates and optimizes five green technologies: wind turbine, solar photovoltaic system, rain water harvesting and utilization system, natural ventilation and roof sky lighting. The design was conceptualized based on the experiences acquired from meteorological data for Malaysian application. The V-shape top roof which was designed above the wind turbine was able to increase the wind speed by the venturi effect before the wind interacts with the wind turbine located between the roofs, hence improve the performance of the wind turbine. An automatic cooling and cleaning system with a stream of water was designed to clean and cool the roof which can improve the electrical efficiency of the solar photovoltaic modules. The ventilation vents of the system allow warm air inside the building to be ventilated out from the building by the pressure difference caused by high speed wind due to the roof design. The skylighting in the system improve the living comfort level and reduce power consumption of artificial lighting. Technical assessment of the system showed the estimated annual energy generated was 21205.65 kWh, estimated energy savings was 1839.6 kWh, the estimated annual ventilation rate was 2.17 × 108 m3 and reduction of CO2 emissions was 17767.89 kg/yr.