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Abstract: With an aim to partially replace conventional diesel fuel, this work investigated the impact of injecting hydrogen into an intake manifold of a diesel engine on its performance. Due to the benefits of hydrogen fuel, such as its high calorific value and flame velocity, it can be used in a dual-fuel mode of operation with diesel. The experiment was carried out for various engine loads with engine speed maintained constant at 1500. By using a digital volume flow metre, hydrogen was injected at three different volume flow rates, namely 3, 6, and 9 lpm. Engine combustion, emission, and performance parameters were evaluated for different hydrogen flow rates and compared to sole diesel. The result revealed that the brake thermal efficiency of the engine increased, whereas the brake-specific fuel consumption decreased due to hydrogen enrichment. The hydrocarbon and carbon monoxide emissions were lower in dual fuel mode when compared to sole diesel operation under all load situations. On the other hand, Oxides of Nitrogen (NOx) emission increased with hydrogen flow rate and resulted in higher NOx than diesel. Furthermore, hydrogen enrichment increased the values of the peak heat release rate and cylinder pressure by a significant margin from the corresponding values given by diesel fuel. Among the evaluated H2 flow rates, 9 lpm is found to be the best, demonstrating enhanced engine characteristics background: Due to the benefits of hydrogen fuel, such as its high calorific value and flame velocity, it can be used in a dual fuel mode of operation with diesel. The experiment was carried out for various engine loads with engine speed maintained constant at 1500. objective: By using a digital volume flow metre, hydrogen was injected at three different volume flow rates, namely 3, 6, and 9 lpm. Engine combustion, emission, and performance parameters were evaluated for different hydrogen flow rates and compared to sole diesel. method: The result revealed that brake thermal efficiency of the engine increased, whereas the brake specific fuel consumption decreased due to hydrogen enrichment. The hydrocarbon and carbon monoxide emissions were lower in dual fuel mode when compared to sole diesel operation under all load situations. conclusion: Among the evaluated H2 flow rates, 9 lpm is found to be the best, demonstrated enhanced engine characteristics.

In this research, gasoline engine performance and emission characteristics were studied when powered by diisopropyl ether-gasoline blends. The main objective of this study is to determine the behavior of diisopropyl ether-gasoline blends at various engine speeds and compression ratios. Further, the engine parameters were optimized using the response surface methodology. Enriched oxygen, higher latent heat of vaporization, and the readily volatile nature of the fuel enhanced the brake thermal efficiency and lowered the hydrocarbons and carbon monoxide due to a better combustion rate. The developed model exhibited superior R2 values with a 0.957 desirability factor. The optimum parameters such as speed, compression ratio, and fuel-blend concentrations were found at 2250 rpm, 10:1, and D25 (75% gasoline and 25% diisopropyl ether), respectively. The responses for the optimal input parameters were brake thermal efficiency (31.53%), specific fuel consumption (0.2923 kg/kWh), carbon monoxide (0.14% by Vol.), hydrocarbons (31 ppm), and oxides of nitrogen (708 ppm). The predicted values for optimum engine parameters were validated with the experimental data, and their percentage of absolute error was found to be less than 5%. Thus, the study concludes that diisopropyl-ether gasoline blends can be used as an alternative fuel to enhance the brake thermal efficiency and reduce the pollution level, and the proposed numerical model can predict the responses with high accuracy. WOS:000862659300004 Q1

This study focuses on effectively utilizing the biodiesel extracted from Azolla (third-generation biofuel), which is regarded as a renewable energy source, for fueling diesel engines. Biodiesel is unique due to its increased viscosity and different fatty acid composition, which proved difficult to attain better engine performance with a mechanical type injection system. This study expands on the previous investigation in modifying the fuel system when using Azolla biodiesel by using a common rail fuel injection system with wider injection flexibility. Considering the lack of more engine optimization studies for Azolla biodiesel, a parametric study is conducted by changing the fuel injection pressure in the range between 300 bar and 900 bar for diesel engine fueled by B20 (20% Azolla +80% diesel) blend. The experimental engine study revealed that the physical properties of the fuel adversely affect the in-cylinder combustion, which leads to poor engine performance and higher emissions at lower injection pressure (300 bar) for B20 when compared to diesel. As the injection pressure increases, the fuel atomization and other spray characteristics are enhanced and thereby improve the combustion. The Brake Thermal Efficiency (BTE) for B20 at 900 bar injection pressure is 3% higher than the diesel fuel at 300 bar injection pressure under full load conditions. The HC, CO, and smoke emission in the engine exhaust for B20 at 900 bar injection pressure was reduced by 13.3%, 28.5%, and 12.3%, respectively, when compared to diesel. Overall, this study recommends the operation of Azolla biodiesel blend in diesel at 900 bar fuel injection pressure to attain improved engine characteristics. WOS:000862937200005 35977574 Q1

In the present study, experiments were conducted to compare the effect of oxide layer formation on the piston crown coated using Micro-Arc Oxidation (MAO) with uncoated piston on the combustion and emission characteristics of the port injected Spark Ignition engine fueled by gasoline. The micro-arc oxidation (MAO) coating technique is the modern process to form a ceramic oxide layer on the reactive metal substrate (base metal) by electrochemical and electro-thermal oxidation in an alkaline electrolytic solution. Using MAO technique, an oxide layer of thickness 72 μm was formed on the piston crown. This oxide layer acts as a thermal barrier to reduce the in-cylinder heat rejection and increase the durability of the piston by withstanding high temperature and pressure produced during combustion. Combustion flames have been captured using the AVL combustion analyzer to analyze the development and propagation of flames within the engine cylinder. From the flame images, it was observed that propagation of flame was faster in MAO coated piston compared to uncoated piston. This is because of higher local temperature inside the combustion chamber that was resulted due to low thermal conductivity of MAO layer. It was also found that carbon monoxide (CO) and hydrocarbon (HC) emissions were reduced as a result of efficient fuel combustion, while NOx emissions increased because of increased combustion temperatures for MAO coated pistons. Keywords: Electro-thermal oxidation, Flame propagation, Micro-arc oxidation, Piston crown, Thermal barrie

IF=5.578; International audience; Currently, India imports 84% of its total oil needs and aims to bring that down to 67% by 2022. To aim for this, the hunt for sustainable production of non-toxic, renewable, and low-cost alternative fuel sources is the need of the hour. Azolla microphylla plant which grows on the water surfaces can be a potential feedstock for the production of biodiesel. The oil was extracted from the azolla plant by the solvent extraction method. The biodiesel was produced from the azolla oil through the transesterification process. The azolla biodiesel was blended with the diesel in the ratio of 25:75, 50:50, and 75:25 by volume and tested in a diesel engine at the part and maximum load conditions. The engine characteristics of the azolla biodiesel blends, neat azolla biodiesel, and sole diesel were compared. The result showed that brake thermal efficiency (BTE) was highest for the B25 (25% azolla biodiesel, 75% diesel) blend with a value of 25.9% which was less than sole diesel, whose BTE value was 26.8% at maximum load. The high viscous nature of biodiesel blends results in inferior evaporation and improper air–fuel mixing process. Due to this, the B25 blend gave the least CO, HC, and smoke emissions among the test blends, but slightly higher than that of neat diesel. The NO emission for diesel was 852 ppm, 882 ppm, and it is 806 ppm, 824 ppm for B25 at the part and maximum load respectively. The peak cylinder pressure for diesel and B25 blend was 50.8 bar and 49.4 bar respectively at maximum load.

In this research, an ample attempt was made to make use of oil extracted from bergamot fruit peel, which can be regarded as a renewable energy source. A systematic experimental approach was adopted to evaluate the feasibility of bergamot peel oil (BGT) as a substitute for gasoline fuel in spark-ignition (SI) engine applications. The oil derived from the rinds of the bergamot fruit was blended in gasoline on a volume basis in the ratios of 10:90, 20:80, 30:70, and 40:60 and experimentally tested in a multi-point fuel injection (MPFI) installed SI engine. The fuel properties of the BGT and its blends were tested. Endoscopic visualization technique was used to analyze the spatial flame distribution on a crank angle basis for the gasoline and bergamot blends. Also, the performance, combustion, and emission characteristics of bergamot-gasoline blends were evaluated, and the results were compared with sole gasoline at various engine brake powers. The endoscopic results revealed that bergamot-gasoline blends exhibited higher flame spread than sole gasoline. The performance study revealed that the brake thermal efficiency and specific fuel consumption exhibited by bergamot-gasoline blends were almost equivalent to that of sole gasoline. The mean in-cylinder pressure was marginally higher, and peak pressure crank angle degree was slightly advanced for bergamot-gasoline blends in comparison to that of gasoline fuel. With an increasing concentration of BGT in the blend, the hydrocarbon (HC) and carbon monoxide (CO) emission decreased at the expense of nitrogen oxides (NOx). Furthermore, BGT exhibits a research octane number (RON) of 80 and a calorific value comparable to that of gasoline, making it a potential candidate for SI engines. From the outcome of this study, it can be concluded that BGT could be a promising alternate biofuel for the partial replacement of gasoline in SI engines. © 2022 Elsevier Ltd 2-s2.0-85123890947

The experimental investigation is performed on the MPFI spark-ignition engine fuelled by 20% camphor blended gasoline (CMO20) at various load conditions. In order to improve its performance characteristics, 2-methyl furan (2-MF) is added as an additive to the CMO20 blend in the proportions of 1%, 2%, and 3% by volume. In this study, the endoscopic combustion visualization technique is employed to compare and analyze the changes observed in the spatial flame characteristics between the test fuels. Also, the effect of 2-methyl furan as an additive with CMO20 blend on the engine combustion characteristics is studied. From the endoscopic results, it is found that the flame spread area with respect to different crank angle positions increases with2-MF concentration in the CMO20 during the early and middle stages of the combustion. The engine characteristics study results revealed that the CMO20 blend with 3% 2-MF gives a brake thermal efficiency (BTE) of 27.22% which is higher than sole gasoline and CMO20 blend whose values are 26.82% and 26.05%respectively at 8 kW load. It is observed that the early start of combustion and faster burn rate associated with 2-MF increased the cylinder pressure and heat release rates of the CMO20 blend. The CO and HC emission decreased by about 3.75% and 4.76% for 3% 2-methyl furan blended CMO20 blend when compared to sole gasoline and NOx emission slightly increased.

The low carbon biofuel (pine oil) derived from the pine tree is endowed with enhanced fuel properties with good octane rating and can be used for SI engine applications. In order to operate pine oil blends with improved fuel efficiency, engine design modification is required. This work investigates the change reflected on the engine characteristics of the port fuelled SI engine due to a thin thermal barrier coating layer formed on the piston crown using the Micro-arc oxidation technique. Furthermore, an endoscopic visualization technique was adopted to compare the combustion flames of uncoated and coated piston engines fuelled with pine oil blends. The coated piston engine fuelled by pine oil blends displayed improved peak in-cylinder pressure and heat release rate. Among the pine oil blends, P20 (20% pine oil + 80% gasoline) blend showed superior engine characteristics at all engine load conditions. The brake thermal efficiency of the coated piston engine fuelled with the P20 blend was improved by 1.8% compared to the uncoated piston fuelled with gasoline. With the P20 blend, the CO, HC emissions were decreased by 8% and 14% respectively and NO emission was increased by 19% for coated piston when compared to gasoline with an uncoated piston engine.

This research work endeavours to study the effect of 2-butoxyethanol blended gasoline on the engine in-cylinder spatial flame propagation, performance, and emission characteristics of a twin-cylinder spark ignition engine at a constant speed of 2400 rpm. The four blends were prepared by adding 1%, 1.5%, 2%, and 2.5% 2-butoxyethanol by volume proportion to the sole gasoline. The visual characteristics of the spatial combustion flame propagation were studied by flame visualization technique using engine endoscope. The captured flame propagation images were analyzed by the combustion diagnostic tool and digital image processing method to compute the flame speed. The results show that the percentage increase in flame speed for 2BE10, 2BE15, 2BE20, and 2BE25 blends is 0.046%, 0.2%, 0.8%, and 1.4% respectively as compared with gasoline. The peak in-cylinder pressure and heat release rate of 2BE25 (97.5% gasoline + 2.5% butoxyethanol) fuel blend is higher by 1.9 bar and 5.06 kJ/m3deg when compared to the sole gasoline whose values are 31.35 bar and 74.322 kJ/m3deg. All the butoxyethanol blends showed a slight improvement in brake thermal efficiency. At full load condition, the CO and HC emissions of 2BE25 blend are decreased by about 15.6% and 9% respectively, whereas NOx emissions of 2BE25 are increased by 10% when compared to that of sole gasoline.

The investigation on the influence of swirl induced piston on the diesel engine characteristics powered using papaya biodiesel blends was studied. Papaya oil biodiesel, extracted from papaya seed, was blended by volume ratio of 25:75, 50:50, 75:25, and 100:0 with diesel and tested in a diesel engine. The fuel properties of the biodiesel blends were tested and a detailed fuel characterization was performed to analyze their feasibility as a partial substitute fuel. The experimental research study using a standard piston revealed that the B25 blend (25% papaya seed biodiesel, 75% diesel) shows Brake Thermal Efficiency (BTE) close to that of sole diesel. In order to improve the engine performance and pollutant emission for the B25 blend, a slight modification on the piston bowl geometry was introduced. Based on this, six helical holes with diameters Φ2, Φ2.5, Φ3, and Φ3.5 were drilled on four different piston crown surfaces to enhance the swirl ratio and turbulence. A numerical investigation was performed initially with modified piston geometries to understand the fundamental effects of swirl air motion due to piston modification. The numerical investigation results show that Φ2.5 mm hole size piston produces better swirl motion with increased uniform swirl velocity. The turbulent kinetic energy for the modified piston was higher compared to convention piston due to swirl enhancement. With this justification, investigation of the B25 blend was performed experimentally with three different pistons having six helical holes of size Φ2, Φ2.5, and Φ3 mm respectively. The experimental results showed improved engine characteristics for Φ2.5 mm hole piston due to swirl enhancement as indicated in the numerical study. The BTE with Φ2.5 mm hole piston for the B25 blend was 5.6% higher when compared to the conventional piston for diesel fuel. On the other hand, exhaust emissions such as HC, CO & Smoke are decreased with Φ2.5 mm hole piston for B25 blend by 17.9%, 30.5%, and 11.6% when compared to the conventional piston for diesel fuel.

The current research paper deals with the experimentation on direct injection diesel engine characteristics for different proportions of diethyl ether in diesel-hydrogen-cashew nut shell liquid blends. Initially, the optimized B20 (20% CNSL and 80% diesel) blend was tested with different proportions of hydrogen such as 4, 6 and 8 L per minute which were optimized at 6 lpm H2 flow rate. The diethyl ether, of 2%, 4%, and 6% proportions, is blended with B20 in which the 6 lpm H2 flow rate was maintained as constant. The experiments were conducted in a single-cylinder diesel engine with a constant speed of 1500 rpm. From the experimentation, it was revealed that the brake thermal efficiency got increased whereas the exhaust emission of both Carbon monoxide and hydrocarbon got decreased when H2 is added with CNSLB20. But the NOx emission got increased with H2 addition. Further, the 6 lpm H2-CNSLB20 and diethyl ether with 6% blends exhibited 43% and 50% decrease respectively in hydrocarbon and CO emissions, when compared to CNSLB20. The brake specific fuel consumption got reduced up to 45% in the fuel combination mentioned above. Meanwhile, when DEE was added with 6 lpm H2-CNSLB20 fuel combinations, the NOx emission, in-cylinder pressure, and heat release rate were increased.

The strive for mitigation of toxic pollutant emissions and carbon footprints has resulted in the incursion of many renewable alternate fuels, produced from bio-derived sources. Amongst them, biodiesel, an ester of vegetable oil, has amassed immense popularity and interest for diesel engine applications. In order to operate higher blends of biodiesel in a diesel engine, engine design modification strategies are essential. This study investigates the effect of nozzle hole geometry on the characteristics of a diesel engine fueled by biodiesel. Based on this modification, the number of nozzle holes was increased from three to five and the engine characteristics were examined for the higher blend B50 (50% kapok biodiesel + 50% diesel). Modifying the nozzle hole geometry resulted in improved combustion characteristics on account of expected enhanced fuel atomization and air/fuel mixing process. The experimental study revealed an increase in peak heat release rate and in-cylinder pressure of 32.5% and 10%, respectively, for B50 when the number of nozzle holes was increased from 3 to 5 at full load condition. Furthermore, the ignition delay was shortened with a shorter burn duration (improved combustion rate) as the number of nozzle holes is increased. The modification of nozzle hole geometry offers the benefit of improved engine performance with the increase in brake thermal efficiency of 6.1% for 5 hole nozzle geometry when compared to 3 hole nozzle geometry at full load condition. Finally, from the emissions front, HC, CO, and smoke decreased with the increase in the number of nozzle holes at the penalty of increased NOX emission.

This paper attempts to explore the impact of the addition of 1,4-dioxane (DOX) with gasoline by volume proportion of 1.5%, 3% & 5% as a performance enhancer in the spark-ignition engine. The DOX possess two oxygen molecules in its chemical structure with good flammable characteristics, and also results in good miscibility and stability with gasoline. The endoscopic technique is employed for spatial visualization and characterization of the combustion flame on the crank angle basis. Spatial flame characteristics and temperature distributions are evaluated by processing the captured digital images. The result shows that flame initiation and propagation are advanced and faster with the addition of DOX in the gasoline respectively. The ring structure and inherent oxygen content of the DOX increased flame speed and improved the combustion characteristics. From the performance and emission analysis, it is found that brake thermal efficiency of gasoline fuel is 24.72%, which is less when compared to the brake thermal efficiency of DOX3 (gasoline 95% + DOX 5%), whose value is 25.42% at full load condition. The HC and CO emissions are decreased by about 6.8% and 10.3% for the DOX3 blend when compared to sole gasoline at full load. This is due to the presence of inherent oxygen and faster burn rate exhibited by the DOX blend which promotes fuel oxidation. NOx emission increased slightly with an increase in the DOX percentage.

Optimization of fuel injection strategies can maximize the utilization of biodiesel by addressing the issues concern with fuel consumption, engine performance, and exhaust gas emission. In the midst of the pervasiveness of plant-based biofuel, this paper focused on maximizing the pine oil biodiesel usage in a diesel engine having common rail direct injection (CRDI) system without any engine modifications. Pine oil derived from pine tree resins, has shown impressive fuel properties such as lower viscosity, flash point, boiling point and comparable calorific value to diesel. In this study, the impact of high fuel injection pressure on the engine characteristics of a diesel engine fueled by 30% pine oil biodiesel blend (P30) was analyzed. At standard 200 bar fuel injection pressure, the brake thermal efficiency (BTE) of P30 biodiesel blend was decreased compared to sole diesel. To improve the utilization and performance of the P30 blend, fuel injection pressure increased from 200 bar to 350 bar at a step of 50 bar. The results show that BTE and combustion characteristics are improved with an increase in injection pressure. The P30 fuel exhibits maximum BTE of 26.1% at 350 bar which is 6.9% higher the BTE of diesel at 200 bar. Exhaust emissions (CO, HC & Smoke) decreased gradually with increase in fuel injection pressure due to high atomization of fuel, faster evaporation, and formation of the better air fuel mixture. At 100% load condition, the P30 blend shows a maximum decrease in CO and HC emission at 300 bar, which is 16.6% and 13.1% less respectively compared to sole diesel at 200 bar injection pressure. The NOx is increased by about 9.4% for P30 blend at 350 bar when compared to that of Diesel at 200 bar. Thus, the blending ratio of pine oil biodiesel in the diesel can be extended by increasing the fuel injection pressure.

This paper endeavors to study and investigate the performance of pine oil as a replacement of Gasoline in a spark ignition (SI) engine. The pine oil was blended with gasoline in proportions of 10, 20 and 30% by volume and tested in twin cylinder engine. The spray and combustion images captured by endoscopic visualization technique were analyzed and the characteristics of the spray and flames of the pine oil blends were compared with that of standard gasoline. The performances were found to be superior at full load with 20% pine oil in terms of achieving the highest brake thermal efficiency (BTE) of 26.68%, the lowest CO and HC emissions, earlier start of combustion than that of gasoline and the highest heat release. The study has also indicated that the performances deteriorate with further addition of pine oil.

This paper reports the results of experimental work carried out on a twin-cylinder gasoline Port Fuel Injection (PFI) engine fueled with lemon peel oil blends. Flame visualization photography is used along with combustion diagnostic tools to investigate the effects of non-octane enhancer bio-fuel lemon peel oil (LPO) on the combustion, performance and emission characteristics of the gasoline engine. The captured combustion flame photographs are post-processed using MATLAB code to single out high diffusion flame regions. The oil extracted from lemon grinds is blended with gasoline in the ratios of 10%, 20% and 30% by volume and tested in the engine at different load conditions. The flame images of 20% and 30% LPO blends show higher diffusion flame regions whereas 10% LPO blend shows least. The gasoline at 80% load shows the least diffusion flames. But the same gasoline shows higher diffusion flame at full load. Among the blends, 10% lemon peel blend shows a better heat release rate compared to gasoline. From the performance analysis, it was determined that the brake thermal efficiency of 10% LPO blend increased by 3% over sole gasoline at full load. The CO, HC, and NOx emission were decreased by 5%, 6.3% and 5% for 10% LPO blend compared to gasoline. From the results, it is concluded that the LPO up to a maximum of 10% by volume can be added with gasoline to improve the performance and emission.

This research revisits on high strength concrete (HSC) using common admixtures, looking at the fundamental requirement to achieve the HSC. Basic requirement of HSC is low water-cement (w/c) ratio. In this project, silica fume (SF) is the mineral admixtures chosen to be applied in the mix, and Super plasticizer (SP) is the chemical admixtures used to enhance workability while reducing water content. The SP and SF portions influence on compressive strength are studied. Concrete cubes size 100 x 100 x 100 mm are casted and tested for compressive strength. The highest average 7 days’ compressive strength achieved is about 49 MPa. Thus, the expected strength after 28 days is 70 MPa, equivalent to concrete grade C70. In this study, the mix with 10% of silica fume to cement content, and 0.04 liter of super plasticizer to one m 3 concrete mix seems to produce the best result.

Water is the most important resource in times of emergency and during military missions. In addition, if there is a war in a country, sources of clean water are essential for life. But, the safety and cleanliness of the river water for the campers and hikers still uncertain. Usually, polluted and contaminated river water is not safe to be directly consumed by human. However, this problem can be partly resolved by using water filter where the river water can be consumed directly after the filtration process. In respect of that, this study was conducted to design the filter media for personal water purification system. Hence, the objective of this work also is to develop a personal, portable dual purpose handy water filter to provide an easier way to get safe, clean and healthy drinking water for human wherever they go. The water quality of samples collected before and after filtration were analyzed. Water samples were taken from a waterfall near Lestari Block and Lake beside Marine Centre UPNM Campus. The ...

The research is conducted to study the exact need of the signage at disaster prone area. The smart signage is needed to increase the safety, reduce the search and rescue time and finally will ease the help to arrive at the relieve center in any condition at any time without interruption. Signage implementation for disaster relief centers is still a foreign matter in Malaysia. The level of preparedness to the natural disaster mainly flood among our citizens is inadequate. Here the signage which usually used as a tool to help and protect the health and safety of the road users, employees and work place visitors. For many years, the signage has played its part miraculously to provide vivid information to the users in whatever condition. The signage also could be used as an indicator or information provider for the natural disaster victims to move to a safer place on time. Sometimes, the victims would not have sufficient time to safe themselves due to lack of information and time. Thus, it can be concluded that the signage at disaster prone area is vital.

Sustainable development becomes the significant tool of planning and design of building structures and infrastructures in this decade. The land use development for neighbourhood construction should be protected from being overused and devastated. Malaysia must starts to incorporate sustainable neighbourhood planning and design so that the future generation can be benefited from this type of development. However less focus is being paid to this type of development which needs attention to be given especially on small-scale green areas. The main concern of this paper is to address the practice of sustainable neighbourhood planning and design in Malaysia as it gives much impact to the living environment of a group of community. The issues pertaining Malaysian sustainable development planning and sustainable neighbourhood design were discussed in this paper. Results from the Malaysian Local Council Structure Plan review were discussed to highlight the sustainable neighbourhood importance. The result indicates that the sustainable neighbourhood planning and design in Malaysia needs to be improved over the current practices to create more environmental-friendly neighbourhood.

Hymenocallis littoralis (Jacq.) Salisb (Melong kecil) commonly known as 'Spider Lily' is an herbaceous plant from the family Amaryllidaceae. Study was carried out to determine the effect of H. littoralis leaf extract on the growth and morphogenesis of two pathogenic microbes, Candida albicans and Escherichia coli. The leaf extract displayed favourable anticandidal and antibacterial activity with a minimum inhibition concentration (MIC) of 6.25 mg/mL. Time kill study showed both microbes were completely killed after treated with leaf extract at 20 h. Both microbes' cell walls were heavily ruptured based on scanning electron microscopy (SEM) analysis. The significant anticandidal and antibacterial activities showed by H. littoralis leaf extract suggested the potential antimicrobial agent against C. albicans and E. coli.

o-ChlorobenzylideneMalononitrile (CS) is a riot control agents (RCAs) that is a non-lethal compound that has relatively short onset and limited duration of action by temporarily incapacitating human through irritating the skin and mucosal membranes on eyes, airways and digestive tract. This research was aimed to find out whether military personnel in Malaysian that is exposed to CS in a confined gas mask facility during a gas mask testing training would affect the respiratory health, especially the lung health symptoms manifested and their lung functions. A total of 58 military personnel participated in this study where 29 of them are NBC trainers and 29 others are the control group. The experiment was conducted onto participants via interview using a standardized Medical Research Clinical Questionnaire (MRCQ) (UK) 1986 and spirometer method for lung function tests.

Dam provides many benefits to the society, but it can also cause extensive damage to downstream area when it fails. Dam failure can cause extensive damage to properties and loss of human life due to short warning time available. In general, dam spillway was designed to drain the maximum discharge from the dam during the Probable Maximum Flood (PMF). The spillway is functioned to prevent the dam from failure due to overtopping, which can lead to the dam failure. Dam failure will result in large volume of water travelling at very high velocity to the downstream area of the dam. It can cause extensive property damage, destruction of important facilities, and significant loss of human life along the way. Due to the potential of high hazard it poses to the downstream area, a dam break analysis is considered very essential. This paper focuses into the dam failure analysis for Kahang Dam by prediction of breach flow hydrographs and generation of inundation map at downstream area. From the PMF scenario simulation, the maximum inflow is 525.12 m3/s and peak discharge from the dam during dam failure is 6188m3/s. The results are able to provide information for preparation of Emergency Response Plan (PMF), in which appropriate steps can be taken by relevant authorities to avoid significant loss of human lives.