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Effect of emulsifier on physical properties of cup lump modified emulsified bitumen residues
Get PDFThe improvement of physical properties of emulsified bitumen residues is the prime concern for researchers to improve the performance of cold mix asphalt and different types of polymers are incorporated in emulsified bitumen for this purpose. However, the bitumen emulsion is usually prepared with the help of emulsifier and the function of emulsifier in the emulsions is to reduce the interfacial tension on the surfaces of bitumen and water droplets which results in a stable droplets suspension system for a sufficient period of time. Despite using it as an emulsifying agent, the impact of emulsifier on physical and rheological properties of bitumen emulsion's residues is never studied before. In this study, different types of bitumen with pen 80/100, 60/70 and Cup lump rubber (CLR) modified bitumen were emulsified at 0.5%, 1% and 6.5% emulsifier (Redicote-EM44) content respectively. Physical tests such as penetration, softening point and viscosity were carried out on bitumen residues to investigate the effect of emulsifier. The results indicate that the emulsifier enhances the physical properties of bitumen emulsion residues. The resistance to penetration was improved up to 20% and 16% for the bitumen emulsion residues of 80/100 and 60/70 respectively while it had adverse effect on penetration value of CLR residue resulting in a decreased performance up to 19%. The effect of emulsifier on softening point was not remarkable but has improved SPV of 80/100 and 60/70 bitumen residues whereas the values decreased for CLR bitumen residue. The viscosity results were with better agreement of penetration and softening point results
A factor analysis to establish a group of causes of deferred maintenance at Malaysia’s public university buildings
Get PDFThe building has deferred the maintenance activities either planned or scheduled and delayed from the original schedules by some factors and therefore cause dissatisfaction of the building users commonly become a familiar issue. The public university buildings are an important place, everyone gathers to learn and share knowledge. They are producing future leaders, engineers and industry players. Therefore, it is also the heart of the development of a country. Hence, this study is intended to establish a group of causes factors of deferred maintenance of public university buildings in Malaysia. Questionnaires survey were carried out amongst the targeted respondent and the Statistical Package for the Social Sciences (SPSS) software were used to analyse 220 data collections for factor analysis. The study reveals 42 factors of causes are then classified into three groups. Group 1 is the organization and it displays 20 factors, group 2 is the resources which display 13 factors and group 3 is financial display 9 factors. This study shared useful information and insight knowledge of deferred maintenance of public university buildings in Malaysia
Empowering education transformation through IR 4.0: efforts in improving the quality of Arabic language education
No full textEducation is one of the important aspects and it is becoming the most influential social institution in the society. The impacts of Industrial Revolution 4.0 are not only on industrial and the electronic sector, but the education sector is also affected by it. The main objective of this article is to identify the elements of Arabic language learning implementation amongst teachers and to oversee the challenges faced by the teachers in incorporating technology with Arabic language teaching. This study used a qualitative methodology by collecting and assessing the information from previous studies such as journals, articles and books. This study found that there were four basic elements related to the implementation of Arabic language learning in teaching and facilitating process include teachers' perception, preparation, practice and challenges in implementing and practicing this learning technique. Teachers are required to implement a new approach in PdPc process especially in Arabic language subject
3D finite element modeling of precast wall panels connection under monotonic loading
No full textThe behaviour and possible failure modes of precast wall panels connection under severe loading conditions remain challenging to achieve a reliable connection. Furthermore, the interaction between precast wall panels' interfaces in terms of shear-slip relationship due to adhesion, friction, clamping stress, and dowel action is a complex phenomenon. In this paper, a 3-dimensional nonlinear finite element model was developed to simulate the shear-slip behaviour due to the interaction between the concrete-to-concrete interface of precast wall panels numerically using Abaqus Software and validate the experimental findings of previously published research work. The concrete-to-concrete interface was reinforced with steel bars crossing the shear plane. The constitutive law of materials for concrete and steel, concrete-to-steel bond-slip relationship, and interaction of concrete-to-concrete interfaces are considered. The bond-slip law was employed for the steel bars crossing the shear plane, while a simplified stress transfer approach using perfect bond was considered for the horizontal and vertical reinforcements embedded in both wall panels. The monotonic loading was applied as a displacement control parallel to the shear plane of connection interfaces. This research work will also provide a simplified methodology for incorporating the bond-slip behaviour when modelling the precast wall panel connection under monotonic loading using the connector approach. The purpose of this study is to contribute to a better understanding of simulating the shear-slip behaviour due to the interaction between concrete-to-concrete interfaces with steel reinforcement of precast concrete wall panels under direct shear loading. The essential findings of this study are that the finite element obtained results agreed well with the experimental findings in terms of load–displacement response, and the failure model associated with the connection is a ductile bending failure in the dowel action. The stress distribution of the reinforcing steel bar with different spacing configurations exhibits similar trends along the steel bar
Light bulbs comparison from different brand and working principle
No full textChoosing the best light bulbs for energy saving purpose is common for consumers and mostly will prefer a low power rated bulb. However, some low power rated bulbs are false claimed. Therefore, this paper reports the comparison between light bulbs with different brands in local market. The comparison is carried out in term of light intensity, energy usage, circadian rhythm and price for a few low power rated bulbs. The method used to measure the light intensity was using a spectrometer. The energy usage for all bulbs are measured and eventually the results is tabulated and analyzed. From the experiment, it can be deduced that every light bulb had its own advantages and deficiencies in term of light intensity, energy usage and price. The result also shows that some light bulbs are over rated in term of power usage. The power measured are much higher (88- to 135%) compare to the power rated by the manufacturer. It is hoped that this paper can be used by the consumer as a reference to choose the best bulb for lighting purpose
Development of android-based multimedia to improve student learning outcome in crystal structure subject of engineering materials course
No full textThe study aims to develop and evaluate the android-based multimedia for Crystal Structure subject in the Engineering Materials course. A Crystal Structure is one of the materials contained in the Engineering Materials course. The concept must be mastered well so that students can understand the subject matter being taught. Meanwhile, without being facilitated with adequate media, students experienced difficulties in the learning process. This is because the material of this Crystal Structure subject is abstract and complex. The multimedia development used the Analysis, Design, Development, Implementation, Evaluation (ADDIE) model which consists of five stages. The multimedia developed was validated by experts to assess its feasibility. Furthermore, it was implemented with experimental methods on the control group and the experimental group to find out the impact on improving student learning outcomes. The samples used in this study were 18 DPTM class A students as a control group and 18 DPTM class B students as an experimental group, with an age range of 17-20 years. The results confirm that the android-based multimedia that was developed received a very good response from users and experts. Android-based learning multimedia can facilitate students in understanding the Crystal Structure subject. This can be seen from the increase in learning outcomes in the experimental class using android-based learning multimedia with an N-gain value of 0.94 and categorized in the high category
A piecewise affine system modeling approach of thin McKibben muscle servo actuator
No full textDynamic characteristic of thin McKibben muscle has not yet been fully investigated. Therefore, the objective of this study is to propose a piecewise affine system to model a thin McKibben muscle servo actuator. The static and dynamic modeling of the actuator has been performed using first principle approach. Different models for extension and retraction operations have been presented. The step input responses of the model have been simulated and compared to the actual system response. Result shows that the model’s response is similar to the actual system with steady-state errors of 1.18% for 0.2 MPa input and 0% for 0.25 and 0.3 MPa inputs. The evidence from this study suggests that a piecewise affine system can be used to model a thin McKibben muscle servo actuator, which would facilitate future development of a novel switching controller
Students’ educational game acceptance in higher education in Saudi Arabia
No full textStudies on educational games (EG) have shown growing interest among researchers due to the potential and preferences of the younger generation. Games technology is among the most popular forms of technology nowadays with billions of transactions yearly. Compared to traditional learning, games have features to provide opportunities for more enjoyable and engaging learning. Despite their great potentials, studies done among researchers on educational-game acceptance among students and teachers are still limited. This is due to challenges to design EG that is well-balanced between fun and learning features. Therefore, it is important to explore factors that contribute to the acceptance of EG. Despite many studies done on EG acceptance, most have only focused on the acceptance factors but not on the game features themselves. Thus, this study fills the gap by integrating the game-design factors, namely feedback, challenges, goals, and rewards, into the Extended Technology Acceptance Model (TAM) that contains 10 constructs and 66 items. A quantitative study among 300 survey participants has been administered at Taif University in Saudi Arabia. Data have been analysed using the structural equation modeling by utilising the PLS-SEM tool. Findings show that game-design features, which are challenges, goals, and rewards, are significant on perceived ease of use, while feedback and challenges are significant on perceived usefulness. Features, goals, challenges, and rewards have a significant effect on perceived usefulness, while intention to use educational games is influenced by learning content, enjoyment, and perceived usefulness. In conclusion, several game-design features are important to be incorporated into EG to ensure the presence of its fun elements while not compromising the learning features. Therefore, educational-game designers and developers should integrate these factors in game design and development in order to increase student engagement and acceptance of educational games
Hydrogen-based energy storage targeting for the integrated heat and power system in urban-industrial symbiosis
No full textGreenhouse gaseous (GHG) emissions are significant global challenges, leading to climate change. The industrial sector is the most significant contributor to global energy consumption, burning fuel and emitting GHG. This study aims to extend the Total Site Heat Integration (TSHI) methodology for clean decentralised energy systems to power an eco-city with Urban-Industrial Symbiosis (UIS). The system is assumed to work on the UIS's thermal energy and power systems. A Pinch-based cascade analysis is extended to simulate the hydrogen energy storage to recover thermal and electricity in the energy system, which can determine the hydrogen storage capacity, known as Total Site - Hydrogen Storage Cascade (TS-H2SC). The hydrogen energy storage system is configured to store excess electricity, and waste heat energy potential to be consumed later or sold off by the system. The methodology is demonstrated with an illustrative case study to integrate hydrogen storage for energy recovery in an Urban-Industrial Energy System. In the illustrative case study, the total electricity to be sold to the grid is found at 701 kWh, while the capacity of the Liquid Organic Hydrogen Carrier (LOHC) system is targeted at 2,616 kg of loaded LOHC. The application of a hydrogen storage system is compared with thermochemical energy storage and power storage systems. The research found that the LOHC system with condensing steam turbine rather than ORC has the most significant potential for energy saving in the UIES
Two-dimensional dam break modelling of Beris Dam using HEC-RAS
No full textDam is built for various functions such as water supply, flood and sediment control, electricity generation and irrigation. Floods due to dam breaches create higher peak flows than floods produced by heavy rainfall. When a dam collapses, the stored water may cause devastating catastrophe towards downstream areas by causing fatalities and property damages. The aim of this study is to perform a two-dimensional dam break modelling of Beris Dam due to probable maximum flood (PMF). The HEC-RAS software was used to predict the breach outflow’s hydrograph and produce the flood inundation and velocity map. Dam breach parameters were calculated using Froehlich and MacDonald and Langridge-Monopolis (MDLM) equations. A 4-day simulation conducted showed that a breach was initiated at almost 10.35 am, 34 hours and 35 minutes after the PMF scenario. Peak discharge during the PMF failure is 10,745.12 m3/s at 12.45 pm the next day which is after 2 hours and 10 minutes of dam breach initiation. Felda Lubuk Merbau, Kampung Betong, Jeniang, Padang Serai and Kota Kuala Muda are among the areas affected by the simulated Beris Dam break. Information obtained on flood velocity, depth and arrival time are useful to local authorities in order to respond effectively and immediately in the event of dam break