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Disposing of demolition waste materials has become a global challenging issue due to expanding construction projects and the cost required to discard them. Re-using these materials particularly satisfies the sustainable development goals. Thus, in this study the recycled concrete aggregate (RCA) has been selected in two soil improvement techniques: stone columns and soil replacement to treat peaty soil. The study aims to investigate numerically the potential of using RCA-made stone columns to reduce the settlement and enhance the bearing capacity in highly compressible soil using Plaxis 3D software. The replaced soil (t) thickness varies from 0.25, 0.5, and 0.75 to 1.0m. The depth and diameter of stone columns are 0.4, 0.6 and, 0.8 and 10, 12, and 14m, respectively. The results indicate that the method of stone columns is better than the replacement technique in reducing foundation settlement. Furthermore, the maximum improvement in bearing capacity was achieved when 16 RCA-made columns with 0.8m diameter and 14m long were used; then the bearing improvement ratio (BIR) and settlement reduction ratio (SSR) were found to be 1000% and 0.18 respectively. [ABSTRACT FROM AUTHOR]

Malaysia has introduced 21st-century learning initiatives through the Malaysia Education development plan 2013-2925. Among the focus are learning, teaching, and facilitation (TLF) by teachers in schools. This study aims to understand the knowledge, attitude, and practice of 21st-century education among teachers in the Rompin District, Pahang. This study employs a quantitative approach with the help of a questionnaire. The sample comprised 152 school teachers with simple random sampling techniques. This research employed a descriptive analysis and inferential analysis (Pearson correlation, t-test. The findings showed the moderate level for knowledge (M=2.95, SD=0.22), attitude (M=2.94, SD=0.23) and practices (M=2.90, SD=0.29). The t-test showed a significance difference between knowledge (t=-2.11, df=157, p<0.05) and attitude (t=-2.26, df=157, p<0.05) while there are no significant differences in practice (t=-1.81, df=157, p>0.05). Pearson correlation analysis showed a modest positive relationship between knowledge and practices (r=0.677, p<.01) and a high positive relationship between attitudes and practices (r=0.837, p<.1). In conclusion, the knowledge, attitude, and practices level are moderate among teachers. So, teachers need to improve their 21st-century education from time to time with, among others, short courses. Help from the obligatory authorities and academicians will increase teachers' awareness of 21st-century learning in their lives. This study's implications showed that 21st-century education literacy among teachers can increase the teachers' knowledge, attitude, and practice and always use 21st-century education in their teaching process. [ABSTRACT FROM AUTHOR]

Mobile robots must have the ability to guarantee safety for operation in a dynamic environment and close to other moving objects. There are many research had been conducted to make the robot safer by utilizing sensors and big data technology to make the mobile robot able to navigate autonomously and intelligently. One of the key elements in autonomous robots is communication between robots. In this paper, device-to-device (D2D) technology has been used to develop communication between robots. To establish the algorithm for D2D communications, radio frequency (RF) used as communication protocols that can perform D2D communication in real-time applications. The performance of D2D communication was then be assessed in terms of distance and latency. RF transceiver module has been mounted on the robot with Arduino to allow communication between mobile robot to other mobile robots in order to transfer data from robot's sensors to the other mobile robots. By utilizing the gathered information and data, the robot can assess its surroundings and predict the movement of other robots to avoid collisions between robots. The results show that the RF transceiver module is capable to send and receive data between two robots with latency up to 4.865s. It is envisaged that the proposed module can be very useful for developing D2D communication between robots to operate in dynamic environments. [ABSTRACT FROM AUTHOR]

Application of friction stir welding in joining process has gain much interest in many industry sectors such as in automotives, aerospace and other metal forming area. It is solid state welding process which intended to overcome problems encounter during fusion welding. However incorrect parameter setting could minimize the strength of the joining area which results in total failure of the welded join. Effect of tensile strength with different friction tool's tip with round, square and triangle shape was used with optimized for different spindle speed and feed rate in order to predict the strength ability of the welded specimen. Taguchi Method was used and specimen used was aluminum 6061 T6 where the tool tip was made of low carbon steel. Conventional milling machine was employed with the parameters of rotational and traverse speed are varies from 700 to 1400 rpm and 100 to 200 mm/min respectively. Results shows that rotational speed of 700 rpm, 200 mm/min in tranverse speed and square pin profile gain an optimum strength of welding joint specimen. [ABSTRACT FROM AUTHOR]

Modern technological applications demand engineering parts and structures that have specific property requirements and performance at certain locations. Functionally graded material can be used to serve such requirements, where the microstructure and percentage of composition can be varied with respect to the specific function at that region. The present study deals with the processing, microstructural characterization, and hardness evaluation of functionally graded A356-15 % SiCp metal matrix composite. The A356-15% SiCp Functionally Graded Metal Matrix Composite (FGMMC) is prepared by vertical centrifugal casting technique. Optical microscopy is used to evaluate the gradient distribution of the reinforced SiCp and microstructure of prepared FGMMC. The variation in hardness values along the radial direction due to gradation of SiCp is correlated with the microstructure variation. Wear behaviour of A356-15% SiCp FGMMC test pins taken from outer SiCp rich and inner alloy region is studied for a constant sliding distance of 350m and sliding velocity of 1m/s. The temperature induced wear transition of A356-15% SiCp FGMMC is analyzed under different loading conditions of 60N, 75N, 90N and 105N for particle rich outer pin from room temperature to 350°C. The transition temperature for change in wear behaviour is found to be 200°C and the transition load noticed at 75N for the outer pin. Similarly the inner pin was tested under loads of 45N and 60N for same temperature range. The wear debris collected and the stereo images of worn surface were clearly examined to study the temperature induced wear transition behavior. The outer pin show good wear resistance than inner pin till 60N load even at high temperature up to 350°C due to the SiCp reinforcement. [ABSTRACT FROM AUTHOR]

In rural areas of Sabah, Malaysia, the groundwater source is the only water supply for domestic consumption. Therefore, the monitoring of groundwater quality is essential to adhere to the standards by Malaysia's Department of Environment. This article seeks to evaluate the groundwater quality through the quantitative analysis, and the sampling carried out between January and March 2019. Among national water quality standards sampled including dissolved oxygen, pH, ammonia nitrogen, and total suspended solids. The result showed that the chemical oxygen demand was above the standards, >197mg/l (Station 5) and fall into Class V. However, the index of water quality for all stations indicate Class II with the lowest in Station 5 (80 per cent) and the highest in Station 6 (90 per cent). All stations showed clean category except for Station 5 (moderately polluted). This study also implicates that the water quality assessment could act as a tool in monitoring the groundwater. [ABSTRACT FROM AUTHOR]

The increase in the aging population in the ages of above 60 years old has given huge impact on the socioeconomic, growth and human development of a country. Meanwhile, poor well-being initiatives in a nation contribute more on neglect of elderly welfare, and mental and physical abuse affecting better life quality and satisfaction. Approximately 703 million persons aged 65 years old in the world in year 2019, and it is projected to double to 1.5 billion in 2050. Millions of senior citizens are exposed to two main problems, physical and mental health, and financial capacity. Financial poverty, particularly, is the core in an ageing society due to lack of regular income, the death of a spouse, mounting medical bills, and poor planning for retirement among elderly people. Thus, the main aim of this article is to review the role of financial support in improving elderly well-being. The main implication of this article reacts to government authorities in planning and providing initiatives or assistance for the elderly financially. Therefore, proper welfare, policy and legal services for the elderly require a deeper understanding of the relationship between the individual characteristics of adults and preferred financial components to improve elderly well-being and life satisfaction. For future recommendations, studies through observations, interviews, and empirical investigations would provide evidence the real demand of financial support and its components towards improving elderly well-being. [ABSTRACT FROM AUTHOR]

This study aims to look at the effectiveness of Geography fieldwork study among form six students in Machang, Kelantan. A quantitative approach was applied in this study by using a questionnaire as an instrument. A simple random sampling method was used for the selection of respondents and the total number of respondents was 80 form six students who were taking Geography in some selected schools in the Machang district in Kelantan. Four study variables were used, namely interest, understanding, skills and effectiveness, in the implementation of the Geography fieldwork study. Descriptive analysis was used to examine the level of each variable I, II, III and IV, and inferential analysis (Pearson's correlation and regression) was used to examine the relationships and influential contributions of each study variable. The findings showed that all of the variables, namely interest (M = 2.89, SP = 0.32), understanding (M = 2.87, SP = 0.32), manipulative skills (M = 2.33, SP = 0.50), soft skills (M = 2.75, SP = 0.44) and the effectiveness of the implementation (M = 2.90, SP = 0.30) were at a moderate level. The results of the Pearson's correlation analysis also found that there was a significant positive relationship between the interest and understanding variables (r = 0.538, p <0.005), understanding and manipulative skills (r = 0.556, p <0.005), manipulative skills and soft skills (r = 0.595, p <0.005) and soft skills with effectiveness (r = 0.677, p <0.005). In addition, regression analysis showed that soft skills had the highest impact on the effectiveness of the Geography field study by 45.8% with R2 = 0.581, F (26.030) = 0.324, P<0.05. In conclusion, this study finds that students show an interest, understanding, and skills in the effectiveness of the Geography field study. This shows that the implementation of Geography field study in schools can bring about change among students, and indicates that an effective Geography field study can enhance students' interest, understanding and skills in the subject of Geography and is able to give students the opportunity to be more innovative and to think creatively. [ABSTRACT FROM AUTHOR]

The combustion of the internal combustion engine results in high heat and pressure produce as exhaust gas. The high-temperature exhaust gas will transfer the heat to surrounding via convection, conduction, and radiation. In the combustion chamber, the exhaust valve and its seat will reach high temperatures due to hot gases exit through the engine exhaust port. This high temperature must be reduced to avoid damaging the engine. In this project, the existing material of the valve seat is tested using computational fluid dynamics simulation for heat analysis. Simulation of transient thermal is conducted to study the detailed behavior of heat transfer of the valve and valve seat in the engine. Four copper-based material of the valve seat is selected which is beryllium copper, chromium copper, brass, bronze are simulated. In the simulation, the brass valve seat has the highest heat absorbance rate which averagely 30% higher than cast iron valve seat in terms of temperature differences. Most of the copper-based valve seat can absorb averagely 10% to 30% more heat than cast iron valve seat depends on the material's thermal conductivity. [ABSTRACT FROM AUTHOR]

Objects such as vehicles are considered one of challenging obstruction on the road and very little attention has been made to address its significance on the wireless signal. As such, this paper validates the impact of vehicle obstruction on signal propagation using received signal strength indicator (RSSI) based on the wireless channel measurements of realistic environmental obstruction at 2.4 GHz frequency band. Low mobility IEEE 802.15.4 XBee S2C compliant device which is designed to collect received signal power was used and these devices were deployed at area congested with cars. The channel measurements were conducted on LOS car parking area with two scenarios; single-sided and double-sided vehicle obstruction which mimics the obstruction of metal objects. The effect of existing vehicle on the signal propagation is demonstrated based on RSSI and RMSE. The attenuation profile of vehicular obstruction on wireless signal is modeled and compared with large-scale propagation models. Results show that metal object significantly reduce transmission range and signal power. The findings may incite for future implementation of cooperative deployment program and internet of things (IoT) applications in vehicle-to-infrastructure (V2I) and vehicle-to-vehicle (V2V) communication. [ABSTRACT FROM AUTHOR]

In this paper, the effect of catalyst, Na2SO4 and temperature on carbothermal reduction and nitridation of Langkawi black sand was investigated. Reduction was performed under 100% nitrogen gas (N2) with a temperature range of 1200 °C - 1400 °C for 3 hours soaking time respectively. Four different amount of catalyst, Na2SO4 range from 0% to 15% were investigated in the reaction. By adding of Na2SO4, it is slightly down the reaction temperature from 1400 °C to 1200 °C by using at least 10% of catalyst. Catalyst, Na2SO4 assist the formation of titanium oxycarbonitride (TiOXCyNz) but the concentration of impurities not affected by catalyst. The XRD pattern indicate that titanium oxycarbonitride phase with the composition of TiO0.19C0.53N0.32 at 1400 °C detected from 0%-15% of catalyst. From XRD pattern, increasing the reduction temperature, will increase the formation of titanium oxycarbonitride. With addition of catalyst, the microstructure of the iron particles coarsened whereby this coarsening is important to increase the reduction of ilmenite and titania. [ABSTRACT FROM AUTHOR]

Delay Study is to evaluate the quality of traffic movement along a route and to determine the level of service at a study area. This study can be used to compare and evaluate operational conditions before and after roadway or when intersection improvements have been made. The objective of this study is to compare before and after the improvement of intersection into roundabout in term of delay time and level of service. This study only focused at the intersection which had massive congestion along Pengkalan Weld road. There are two intersections which experience a massive traffic jam during morning peak hour. The worst traffic jam occurs at the intersection connected to Gat Jalan Magazine (Case study area 1) especially for the vehicle coming from south of Pengkalan Weld to north bound. This traffic jam occurs because of the long cycle of traffic signal. The second worst traffic jam occours at the intersection connected to Gat Lebuh Chulia (Case study area 2). It is a 4 leg-intersections without a traffic signal. The traffic jam occur at the particular section because there is no traffic light which could guide the road users to cross that conflict area. The minor road which is from Gat Lebuh Chulia has disrupted the major road which is the Pengkalan Weld road. Thus, the motivation of current research is to evaluate these intersections into the space sharing intersection or also known as roundabout. To achieve this purpose, the simulation VISSIM model had been created.VISSIM software was also used to analyse the field data by using the average speed method. The field data was collected during AM peak hour since it has the highest traffic volume per hour compare to PM peak and off peak. From the result both method (vissim and field data) produced slightly the same result in delay time. This means that VISSIM simulation is acceptable to be used. Second model was develop in order to design roundabout by using the VISSIM simulation. As conclusion, by using Vissim simulation it was found that the improvement from intersection to roundabout had minimized delay time and improvement of LOS by 97.8% for Case study area 1 and 75.6% for Case study area 2. [ABSTRACT FROM AUTHOR]

The simulation process being conducted to determine the air flow effect between the original exhaust system and modified exhaust system. The simulations are conducted to investigate the flow distribution of exhaust gases that will affect the performance of the engine. The back flow pressure in the original exhaust system is predicted toward this simulation. The design modification to the exhaust port, exhaust pipe, and exhaust muffler has been done during this simulation to reduce the back flow effect. The new designs are introduced by enlarging the diameter of the exhaust port, enlarge the diameter of the exhaust pipe and created new design for the exhaust muffler. Based on the result obtained, there the pulsating flow form at the original exhaust port that will increase the velocity and resulting the back pressure occur. The result for new design of exhaust port, the velocity is lower at the valve guide in the exhaust port. New design muffler shows that the streamline of the exhaust flow move smoothly compare to the original muffler. It is proved by using the modification exhaust system, the back pressure are reduced and the engine performance can be improve. [ABSTRACT FROM AUTHOR]

Indoor positioning system (IPS) is a system that is used to locate and navigate inside a building. GPS systems are unusable indoors because it relies heavily on satellite signals. Thus, a number of methods have been proposed by researchers to solve this problem in order to locate user's position inside buildings. In this paper, we propose methods for IPS by utilizing the RSS of Wi-Fi access points (AP) and using trilateration technique. A new algorithm has been developed based on proposed methods. Four Wi-Fi APs have been placed on grid in obstacle-free environment to send the signal to the receiver (i.e. portable personal computer) for determining the position by using trilateration technique. The receiver has been placed on the predefined locations in order to investigate the accuracy of the proposed method. The results gathered after series of experimental works and show an acceptable level of accuracy. The highest percentage of error is 10%. In terms of distance, the actual location varies compared to the one displayed on the application are merely at decimeter level. The level of accuracy is enough to be implemented for indoor positioning usage. [ABSTRACT FROM AUTHOR]