Conversion of carbon dioxide emission using catalytic methanation method in hot mix asphalt

The purpose of this study is to mitigate the carbon dioxide (CO2) emission from bitumen tank combustion unit in hot mix asphalt (HMA) plant. This study has been conducted by introducing the catalytic methanation method to reduce the CO2 emission which majorly contributed to the greenhouse gases emissions in atmosphere. The benefit of using the method is that a high amount of CO2 can be reduced without effecting the asphalt mixture properties which are very crucial to ensure high-quality asphalt pavement service life. This study suggested the conversion of CO2 from flue gases emission to utilize it into methane (CH4). The first stage of the study is the analysis of flue gases emissions from bitumen tank combustion unit in HMA plant by on-site gas analysis and laboratory analysis. The flue gas emission analysis shows that CO2 is the major emission produced by combustion activities in bitumen tank combustion unit in HMA plant which the emission is between 4.95 - 15.55%. For the mitigation stage, Fourier Transform Infrared (FTIR) analysis is done to determine the percentage of CO2 conversion and CH4 formation over the catalyst used. After preparation and optimization, Ru/Sr/Ce (5:30:65)/Al2O3 catalyst calcined at 700°C for 5 hours and pre-treated at 300°C for 30 minutes with compressed air has been proposed as the best catalyst for the application of catalytic methanation method. This is because the catalyst produced the optimum values in term of CO2 conversion and CH4 formation during the reaction. The final stage of the study is the characterization of the catalyst to determine the factors contributed to its catalytic activities. The results show that the higher catalytic activities are caused by the uneven surface of catalyst with well shape hexagonal like particle on it. Besides that, the higher amount of Ruthenium (Ru) element composition in the catalyst, moderate basicity properties of the catalyst, and the higher pore volume in the catalyst also significantly contributed to its higher catalytic activities

RF-DC power conversion of Schottky diode fabricated on AlGaAs/GaAs heterostructure for on-chip rectenna device application in nanosystems

The Schottky diodes enjoined with coplanar waveguides are investigated for applications in on-chip rectenna device applications without insertion of a matching circuit. The design, fabrication, DC characteristics and RF-to-DC conversion of the AlGaAs/GaAs HEMT Schottky diode is presented. The RF signals are well converted by the fabricated Schottky diodes with cut-off frequency up to 25 GHz estimated in direct injection experiments. The outcomes of these results provide conduit for breakthrough designs for ultra-low power on-chip rectenna device technology to be integrated in nanosystems

Evaluation of Emissions by Different Analysis Method at Hot Mix Asphalt Plant Combustion Source

The combustion process for the asphalt mixing in hot mix asphalt (HMA) plant can produce harmful flue gases emission into the atmosphere. Combustion activities produce heat for industrial usage when fuel reacts with oxygen in the air under suitable conditions. High concentrations of undesirable emissions can be formed if the combustion is not properly controlled during the reaction. This paper gives an overview on the method and measurement of these emissions in combustion analysis by focusing on the three types of analysis methods which are laboratory testing analysis, on-site emission analysis, and theoretical analysis. Three types of data were prepared in order to achieve the objective of the study, which are literature study, site visit, and laboratory analysis. The result shows that there is slightly different emission results even though they came from the same source. Clearly, the analysis shows that the air-fuel ratio during combustion can have a significant effect on the emission result. The excess air supplied can cause dilution to the emission and leads to a low emission value

Evaluation of Emissions by Different Analysis Method at Hot Mix Asphalt Plant Combustion Source

The combustion process for the asphalt mixing in hot mix asphalt (HMA) plant can produce harmful flue gases emission into the atmosphere. Combustion activities produce heat for industrial usage when fuel reacts with oxygen in the air under suitable conditions. High concentrations of undesirable emissions can be formed if the combustion is not properly controlled during the reaction. This paper gives an overview on the method and measurement of these emissions in combustion analysis by focusing on the three types of analysis methods which are laboratory testing analysis, on-site emission analysis, and theoretical analysis. Three types of data were prepared in order to achieve the objective of the study, which are literature study, site visit, and laboratory analysis. The result shows that there is slightly different emission results even though they came from the same source. Clearly, the analysis shows that the air-fuel ratio during combustion can have a significant effect on the emission result. The excess air supplied can cause dilution to the emission and leads to a low emission value

Statistical Analysis of Accident Patterns and The Causes at A State Road in Perlis

Data from the World Health Organization have stated that each year, approximately 1.3 million road users are at high risk of a road traffic accident. Therefore, this study aims to evaluate the accident patterns and causes at a state road of Kangar to Alor Setar. The methods used to evaluate the accident patterns are the chi-squared test (CST) and level of service (LOS) survey. The Pearson CST shows that the significant factors for accidents are the age of the drivers, in which people below 30 years old are likely to be involved in accidents ( = 0.037), and type of vehicles used, in which motorcycles are more prone to be involved in accidents ( = 0.000). However, gender shows an equal risk for accident involvement ( = 0.911). The LOS E is observed on evenings of Monday and Friday, indicating the unstable flows of traffic during those periods. Partial least squares structural equation modelling is used to evaluate the causes of accidents from the road user’s perspective via a questionnaire. Before distribution, the questionnaire underwent a pilot study to ensure its validity and reliability. Four hypotheses were developed with the following independent variables: human factors, vehicle factors, environment factors and road condition factors. Results show that the majority of the road users (33.3%) travelled 1 to 3 times per week and 23.1% of them were involved in accidents while travelling on this road. The validity test via the structural model shows that the most significant factors affecting the relationships to the accidents are the road factors (t = 6.166, p = 0.000), the vehicle factors (t = 4.3399, p = 0.000) and the human factors (t = 2.893, p = 0.005). Thus, the factors are significant to the causes of accidents on this road. Countermeasures that emphasise these factors are very important to be considered by authorities to reduce accidents on this road

Effect of aggregate gradation on porous asphalt properties

Rainwater or storm water is very common in Malaysia and even at certain time, several places in this country will face the flooding problem. This condition will give a big trouble to the road in Malaysia as majority of them were made by asphaltic concrete. The run off from the rain water if it is not discharge as soon as possible will cause a lot of problem to the road user as well as for the condition of road itself. Based on the previous study, one of this problem solving is by using porous asphalt as wearing course of pavement. In order of that, this study was conducted to evaluate the effect of aggregate gradation on porous asphalt properties. The method is to compare the properties of Grading A and Grading B based on JKR specification (JKR/SPJ/2008) and binder used is PG76 bitumen. The void ratio of the test specimen was controlled in order to ensure the sufficient permeability of porous asphalt. There are several tests was conducted to evaluate properties of the specimen such as abrasion loss test, binder draindown test, resilient modulus test, creep test, and stability test. The test results indicated that gradation affected the performance and properties of porous asphalt mixtures. Grading B showed the best result in term of the physical properties and performance of porous asphalt mixture. The result from both gradations varies caused by difference of the aggregate size proportion of them. The difference aggregate size proportion resulted in difference arrangement of aggregate skeleton in mixture, thus affected the porosity of mixture. It will also affect an ability of granular to resist cyclic load from the pavement surface, and then affected the physical properties of them

Power conversion efficiency of AlGaAs/GaAs schottky diode for low-power on-chip rectenna device application

A Schottky diode has been designed and fabricated on n-AlGaAs/GaAs high-electron-mobility-transistor (HEMT) structure. Current-voltage (I–V) measurements show good device rectification with a Schottky barrier height of 0.4349 eV for Ni/Au metallization. The differences of Schottky barrier height from theoretical value are due to the fabrication process and smaller contact area. The RF signals up to 1 GHz are well rectified by the fabricated Schottky diodes and stable DC output voltage is obtained. Power conversion efficiency up to 50% is obtained at 1 GHz with series connection between diode and load. The fabricated the n-AlGaAs/GaAs Schottky diode provide conduit for breakthrough designs for ultra-low power on-chip rectenna device technology to be integrated in nanosystems

Prediction of n-AlGaAs/GaAs Schottky diode properties for milliwatt range application

The Schottky diodes enjoined with coplanar waveguides are investigated for applications in on-chip rectenna device application without insertion of a matching circuit. The design, fabrication, DC characteristics and RF-to-DC conversion of the A1GaAs/GaAs HEMT Schottky diode is presented. The RF signals are Well converted by the fabricated Schottky diodes with cut-off frequency up to 20 GHZ estimated in direct inj ection experiments. Preliminary investigation on design, fabrication and DC and RF characteristics of the integrated device (planar dipole antenna Jr Schottky diode) on AlGaAs/GaAs structure is also presented. From the preliminary direct irradiation experiments using the integrated device, the Schottky diode is not turned on due to Weak reception of RF signal by dipole antenna. Further extensive considerations on the polarization of irradiation etc. need to be carried out in order to improve the signal reception. The outcomes of these results provide conduit for breakthrough designs for ultra-low power ori-chip recterma device technology to he integrated in nanosystems