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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.

Rubberwood biomass ash (RWA), which was derived from the combustion of rubberwood biomass in a fuel factory, was obtained for reuse as a natural mineral filler substitute in water-based intumescent coatings. The specific surface area of the RWA was 3.10 m2/g, with the particle's surface areas predominant composed of mesopores, which was justified using the Brunauer–Emmett–Teller Test (BET). Rubberwood ash coatings (RWAC) formulated with 3.0 wt% RWA exerted the most homogenous and durable surface matrix in the Accelerating Weathering Test (AWT). Fire-resistant test (FRT) and thermogravimetric analysis (TGA) demonstrated the incorporation of the RWA with the intumescent flame-retardant formulation, generated positive effects in equilibrium end temperature, thermal decomposition, and weight loss reductions. These effects are most prominent in the RWAC-3, which was comprised of 3 wt% RWA, and 50/40/7 wt% vinyl acetate (VA)/intumescent flame retardant additive (IFRA)/pigment. The RWAC-3 showed the lowest equilibrium end temperature at 131.4 °C, the lowest thermal degradation at 71 wt%, and the highest carbonaceous char formation at 12.8 mm. The Surface Electron Microscopy (SEM) and Energy Dispersive X-Ray Spectroscopy (EDX) results exhibited a dense, compact, and coherent char formation for the RWAC-3 sample. The abundant O and P crosslinking structures in the RWAC-3 contributed to the quality of the char barrier. These results are supported by the evidence from Fourier-Transform Infrared Spectroscopy (FTIR), and X-Ray Diffractometer (XRD), which revealed the stretching of the O–H, P–O–C, and P O molecular functional groups, and the presence of thermally stable phosphate compounds in the RWAC-3.

The utilization of wastes in concrete as bio-based aggregate can alleviate disposal issues as well as preserve precious natural resources. This research highlights the wet grout binder derived from different water-cement ratios (0.65, 0.85, 1.05, and 1.25) in modifying the surface of lightweight bio-based coarse aggregate (LWBCA). In this research, the strength properties of lightweight aggregate concrete (LWAC) mixed with modified LWBCA were evaluated. The outcomes showed that through the replacement of non-treated bio-based aggregate with that of pre-treated grout coating bio-based aggregate, the density of the samples slightly increased. The results indicated that the slump value of the treated LWBCA showed a significant enhancement by almost 45% at 10 min for treated dura oil palm shell at 0.65 water-cement ratios (TDOPS/0.65), as compared to the non-treated bio-based aggregate. In addition, the strength of the TDOPS/0.65 mix shows more appropriate quality enhancement of pre-treated LWBCA when compared to non-treated, and correspondingly the strength properties of the concrete, particularly the significant increment of compressive strength and elastic modulus were recorded at 21% and 31%, respectively. Based on the water absorption test assessment, the LWBCA concrete indicated that good concrete was obtained for all the mixes. Therefore, a new technique of surface modification on bio-based aggregate has shown to be a highly suggested method, which performs as one of the most promising solutions to enhance the interfacial bonding strength. Thus, treatment improves the bio-aggregates to a level without scarifying the quality of the LWAC and substantially mitigating the environmental impact in concrete.

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.

Globally, the COVID-19 pandemic has had both positive and negative impacts on humans and the environment. In general, a positive impact can be seen on the environment, especially in regard to air quality. This positive impact on air quality around the world is a result of movement control orders (MCO) or lockdowns, which were carried out to reduce the cases of COVID-19 around the world. Nevertheless, data on the effects on air quality both during and post lockdown at local scales are still sparse. Here, we investigate changes in air quality during normal days, the MCOs (MCO 1, 2 and 3) and post MCOs, namely the Conditional Movement Control Order (CMCO) and the Recovery Movement Control Order (RMCO) in the Klang Valley region. In this study, we used the air sensor network AiRBOXSense that measures carbon monoxide (CO), nitrogen dioxide (NO2), sulfur dioxide (SO2) and particulate matter (PM2.5 and PM10) at Petaling Jaya South (PJS), Kelana Jaya (KJ) and Kota Damansara (KD). The results showed that the daily average concentrations of CO and NO2 mostly decreased in the order of normal days &gt, MCO (MCO 1, 2 and 3) &gt, CMCO &gt, RMCO. PM10, PM2.5, SO2 and O3 showed a decrease from the MCO to RMCO. PJS showed that air pollutant concentrations decreased from normal days to the lockdown phases. This clearly shows the effects of ‘work from home’ orders at all places in the PJS city. The greatest percentage reductions in air pollutants were observed during the change from normal days to MCO 1 (24% to 64%), while during MCO 1 to MCO 2, the concentrations were slightly increased during the changes of the lockdown phase, except for SO2 and NO2 over PJS. In KJ, most of the air pollutants decreased from MCO 1 to MCO 3 except for CO. However, the percentage reduction and increments of the gas pollutants were not consistent during the different phases of lockdown, and this effect was due to the sensor location—only 20 m from the main highway (vehicle emissions). The patterns of air pollutant concentrations over the KD site were similar to the PJS site, however, the percentage reduction and increases of PM2.5, O3, SO2 and CO were not consistent. We believe that local burning was the main contribution to these unstable patterns during the lockdown period. The cause of these different changes in concentrations may be due to the relaxation phases during the lockdown at each station, where most of the common activities, such as commuting and industrial activities changed in frequency from the MCO, CMCO and RMCO. Wind direction also affected the concentrations, for example, during the CMCO and RMCO, most of the pollutants were blowing in from the Southeast region, which mostly consists of a city center and industrial areas. There was a weak correlation between air pollutants and the temperature and relative humidity at all stations. Health risk assessment analysis showed that non-carcinogenic risk health quotient (HQ) values for the pollutants at all stations were less than 1, suggesting unlikely non-carcinogenic effects, except for SO2 (HQ &gt, 1) in KJ. The air quality information showed that reductions in air pollutants can be achieved if traffic and industry emissions are strictly controlled.

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 global increase in world population is followed with a rise in waste generation and energy needs in various sectors. Organic waste, also known as biomass, is the most substantial contribution of the waste generation and it also can be utilized in energy generation. Therefore, the purpose of this study is to analyze the syngas production from co-gasification using Renewable Densified Fuels (RDF) with gasification temperature, lower heating and gas emission values, on the performance of the biomass co-gasification process in an open-top downdraft fixed bed gasifier. In this study organic waste used woods, coconut fibers and rice husks in pellets to blend the compositions of raw materials during the co-gasification process. The method used is the co-gasification technique with feed pellets WCF (wood-coconut fiber) and RH (rice husk) in various compositions, for example: 100% WCF, with 0% of RH, 75 WCF: 25 RH, 50 WCF: 50RH, 25 WCF: 75RH and all 100% RH with 0WCF. Furthermore, the syngas testing was directly measured on the burner with TCD type Shimadzu 8A gas chromatography. The result showed that the highest reactor temperature in the pyrolysis zone is 700 °C–900 °C which was significantly stable at 800 °C with oxidation temperature of 1000 °C–1100 °C. Furthermore, the result of the synthetic gas showed that the highest lower heating value of 100% WCF pellet composition at 3.582 kJ/Nm3 and lower heating value of RDF blending composition (75:25) at 3.392 kJ/Nm3. The increase in pellet fuels also leads to a rise in the LHV syngas value. These results produced a visually low tar content and ash particles in all compositions by approximately 30–35% of the initial mass, with the lowest ash in 100% WCF pellets composition at 0.25 g.

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 printed circuit heat exchanger (PCHE) is a promising waste heat recovery technology to improve energy efficiency. The current investigation presents the experimental results on the thermal performance of a novel PCHE for low-temperature waste heat recovery. The novel PCHE was manufactured using precision machining and diffusion bonding. The thermal performances, such as effectiveness and NTU values at different temperatures, are evaluated, and water is used as a working fluid. The experimental results indicate that the PCHE’s effectiveness is around 0.979 for an inlet flow temperature of 95 °C. The predominant factors affecting the thermal performance of the PCHE are the inlet flow temperature and the flow rate of the working fluid. In addition, a comparison of the experimental results and the literature shows that the effectiveness of the PCHE is better than the others, which have fewer layers of PCHE fins.

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.

This cool roof system focuses on utilization of rainwater harvesting systems by integrating the smart sensor to cool the roof and attic temperatures for the improvement of comfort level of building occupants. An ideal cool roof technology system is basically made up of these three components: (1) moving-air-cavity (MAC) ventilation, (2) solar-powered fan and (3) rainwater harvesting system. These three main components integrate to perform and control the cool roof system. Four small-scale cool roof models were designed and constructed to inspect the performance of the rooftop and attic temperatures. The experimental work was carried out indoors by employing the halogen lamp as the replacement for solar irradiation, while the ambient temperature is monitored to be around 29.8 °C throughout the test. The temperatures of the rooftop surface, MAC aluminum tube, and attic region were measured by K-type thermocouples to evaluate the performance of the cool roof designs. The solar-powered fans were incorporated into the MAC, which accelerated the airflow rate within the cavity and rejected the hot air out before transferring it to the attic region. Meanwhile, an innovative rainwater harvesting system was executed to cool the rooftop temperature rapidly by reducing the rate of heat transfer to the attic region. The result of this inventive cool roof system (Design Z) has successfully reduced the attic temperature by 10.8 °C compared to the normal metal deck roof model (Design W). The findings of the project revealed that the integrated cool roofing technology system comprises the ability to enhance the comfortability of building occupants toward a long-term sustainable development for a better world.

Global energy demand is rising due to the rapid development and adoption of new technologies in every sector. Hence, there is a need to introduce a clean energy source that does not cause damage to the environment. Aluminium-air battery with its high theoretical specific volumetric capacity is an exciting alternative for post-lithium energy storage and has been at the forefront of energy research for years. However, the conventional aqueous electrolyte-based aluminium-air battery with bulky liquid storage, parasitic corrosion of aluminium in contact with the electrolyte, and formation of a passive oxide or hydroxide layer has precluded its widespread application. In order to achieve successful simplification and cost-effectiveness, a novel idea of a polypropylene-based aluminium-air battery is proposed. In this work, a polypropylene-based aluminium-air battery was constructed using aluminium foil as an anode, carbon fiber cloth as an air-cathode, and Polypropylene and Kimwipes as the separator. The effects of the electrolyte concentration on the aluminium-air battery were investigated and analyzed using various discharge currents. The study showed that the performance of the polypropylene separator is better than that of the Kimwipes separator. The battery capacity is negatively correlated with the concentrations of the electrolyte. At a discharge current of 30 mA, the aluminium-air battery has a specific capacity of 375 mAh g−1 when 1 M of potassium hydroxide was used as electrolyte.

This paper presents a novel cool roof technology system that promotes both passive and active cooling methods in reducing the attic temperature of the building. The project aimed to evaluate the effect of various roof model designs on the heating load to establish the capacity of a cooling roof system by maintaining the thermal comfort level for occupants in the buildings. There are four main components in constructing the cool roof models: (1) metal deck roof, (2) lightweight foam concrete roof, (3) moving-air-cavity (MAC) ventilation and (4) solar-powered fan. Four small-scale cool roof models were built to evaluate the performance of each cool roof designs. The performances of the roof surface and attic temperatures of each designed cool roof models were compared with the conventional metal deck roof. The roof models were conducted indoors by using halogen spotlights. The result of the Roof Design IV with the integration of lightweight foam concrete, MAC and solar-powered fans has effectively reduced the attic temperature by 6.0 °C as compared to the normal roof model (Roof Design I). As a result, this integrated cool roof design comprises the ability to enhance the comfortability of occupants towards long-term sustainable development with the utilization of renewable energy to protect and improve the natural environment.

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.

Recent developments of intumescent fire-protective coatings used in steel buildings are important to ensure the structural integrity and safe evacuation of occupants during fire accidents. Flame-retardant intumescent coating applied to structural steel could delay the spread of fire and heat propagation across spaces and structures in minimizing fire risks. This research focuses on formulating a green intumescent coating utilized the BioAsh, a by-product derived from natural rubberwood (hardwood) biomass combustion as the natural substitute of mineral fillers in the intumescent coating. Fire resistance, chemical, physical and mechanical properties of all samples were examined via Bunsen burner, thermogravimetric analysis (TGA), carbolite furnace, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared (FTIR), freeze&ndash, thaw cycle, static immersion and Instron pull-off adhesion test. Sample BioAsh intumescent coating (BAIC) 4-7 incorporated with 3.5 wt.% BioAsh exhibited the best performances in terms of fire resistance (112.5 &deg, C for an hour under the Bunsen burner test), thermal stability (residual weight of 29.48 wt.% at 1000 &deg, C in TGA test), adhesion strength (1.73 MPa under Instron pull-off adhesion test), water resistance (water absorption rate of 8.72%) and freeze&ndash, thaw durability (no crack, blister and color change) as compared to other samples. These results reveal that an appropriate amount of renewable BioAsh incorporated as natural mineral fillers into the intumescent coating could lead to better fire resistance and mechanical properties for the steel structures.

In this study, surface chemistry, the morphological properties, water retention values, linear viscoelastic properties, crystallinity index, tensile strength and thermal properties of water hyacinth (WH) cellulose were correlated with the degree of mechanical processing under high-pressure homogenisation. An initial low-pressure mechanical shear of WH stems resulted in the ease of chemical extraction of good quality cellulose using mild concentrations of chemical reagents and ambient temperature. Further passes through the homogeniser resulted in an overall improvement in cellulose fibrillation into nanofibrils, and an increase in water retention property and linear viscoelastic properties as the number of passes increased. These improvements are most significant after the first and second pass, resulting in up to 7.5% increase in crystallinity index and 50% increase in the tensile strength of films, when compared with the unprocessed WH cellulose. The thermal stability of the WH cellulose was not adversely affected but remained stable with increasing number of passes. Results suggest a high suitability for this process to generate superior quality cellulose nanofibrils at relatively low energy requirements, ideal for sustainable packaging applications and as a structural component to bioplastic composite formulations.

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.