Performance of Al2O3-SiO2/PAG employed composite nanolubricant in automotive air conditioning (AAC) system

Automotive Air conditioning (AAC) system is the contributor of harmful gasses emission and global warming. In order to solve the issues, investigation on potential improvement in lubrication used in air conditioning system is done to improve the system performance and efficiency. The performance of AAC system namely cooling capacity, compressor work, coefficient of performance (COP) and power consumption was investigated by comparing pure lubricant and Al2O3-SiO2/PAG nanolubricants. Performance of AAC by using different ranges of refrigerant charges (95 to 155 g) and speeds (1200 and 1800 rpm) was investigated. The result shows that the cooling capacity and COP of pure lubricant were relatively lower than Al2O3-SiO2/PAG nanolubricants. The compressor work and power consumptions of Al2O3-SiO2/PAG nanolubricants were greatly reduced. Cooling capacity and COP are enhanced by 102.99% and 23% respectively. The compressor work and power consumption are reduced by 25.9% and 28.24% respectively. From the results, nanolubricants gives more advantages in AAC performance over pure lubricant. Therefore, Al2O3-SiO2/PAG composite nanolubricants is recommended to be used as the compressor lubrication to enhance AAC performances system

Air Quality Study at Different Elevation Levels Using Drone Payload Air Quality Measurement Device (D-PAQ)

Construction sites can be found in both urban and rural areas, often in close proximity to residences. They can thus cause home pollution due to the distance and the materials used. This study aims to visualize PM2.5, PM10, temperature and humidity by producing air quality mapping and correlating parameters at the stadium and construction site. An Arduino-based air quality measurement payload device was developed to measure the air quality by different levels. The drone was used to collect air quality data by mounting the device to the drone. Measurements were taken at three different elevations for each study area, and the application software generates the air quality map based on the location coordinates. The correlation evaluation of the concentration of PM2.5 and PM10 with temperature and humidity was then determined. The results showed that the concentrations of PM2.5 and PM10 at the construction site are much higher compared to the stadium due to the construction activities nearby. Keywords: air quality, unmanned aerial vehicle, mappin

Intensity Stability Comparison Between Different Colors of Laser Pointer

Different source of light can be used as a main light source in an open path optical method. Sunlight, tungsten lamp, LED, laser, mercury vapor lamp and halogen are the example of the light source. It is important to test the stability of the light source used to avoid inaccuracy in the measurement. The purpose of this project is to determine which color of laser has higher stability. Once the light is switched on, the intensity of the light source changes slowly until it comes to a stable state. Each color has different counts of intensity and stability. Different set of laser pointer is used in this project which included blue, violet, red and green color. An open path optical method is used in the experiment. A different color of laser pointer will be used as a light source while spectrometer will act as a detector. The stability for each color of laser pointer is reported in this paper where the standard deviation for each color is calculated to determined which color have a higher stability. Results shows that standard deviation for green color has the smallest value among these four colors where the standard deviation is15.97.Color with smaller standard deviation has the highest stability

Study of factors influencing construction delays at rural area in Malaysia

Construction is one of an important industry which contributes to the economic growth in Malaysia. However, it has been revealed that 79.5 percent and 66.7 percent of the public and private projects were not completed within the time specified in the contracts out of 359 projects in Malaysia. Therefore, the purpose of this study is to investigate the delay factor caused project delay at rural area. A 5-points Likert scale questionnaire survey were answered by 111 respondents which having experience with rural construction project. The questionnaire data were analysed by using Relative Importance Index (RII). Five top factors were determined from this study based on their RII values which are improper construction method implemented by contractor, weather condition, difficulties in providing delivery to site, breakdown of site equipment, and poor qualification of contractor’s technical staffs

Level of Service for Pedestrian Movement towards the Performance of Passenger Information in Public Transport Stations in Klang Valley

Rapid growth in car ownership in Malaysia plays a major role to traffic congestion. Hence, public transportation is crucial to cater the residents in high-density area especially in Klang Valley. Signage information in public transport station is one of an important passenger information system. Poor placement of sign information will decrease the efficiency of passenger flow and caused congestion in the station. Passenger information system is very useful for trip planning and decision making. Therefore, it is interesting to study the performance of passenger information system in focusing the movement behavior of pedestrian at non-peak period. Thus, the study on pedestrian movement during non-peak period on weekdays and weekends in mass transit stations and bus transit stations in Klang Valley was carried out by using video observation. The observation of the pedestrian movement was made in Mass Transit Station 1 in the middle of Kuala Lumpur and Mass Transit Station 2 in southern of Kuala Lumpur. The other site was focused at Bus Transit Station 1 in Putrajaya and Bus Transit Station 2 in Kajang. Findings shown that Mass Transit Station 1 having the best facility in terms of passenger information which the level of service obtained is LOS A, while the lowest level of service which is LOS E was obtained in Bus Transit Station 2

Effects of Staggered Array of Cubical Obstacles on Near- Ground Wind Environment and Air Quality

Deterioration of natural ventilation in outdoor environments due to rapid urbanisation has raised the issues pertaining to pedestrians’ thermal comforts and pollutant exposures. There are substantial interests in the recent years to get an insight on how deficient these situations are and later propose the appropriate urban layout for optimum wind ventilation in a dense urban area. The objective of this paper is to numerically study the effects of urban layouts (i.e., staggered arrangements and cubes’ densities) on wind ventilation and air quality near the ground subjected to one wind direction; perpendicular to the disposition direction. Computational fluid dynamics simulations were carried out by the use of standard k−ε turbulence model and found to be in fair agreement against the experimental data. Our result showed that loosely packed cubes exhibited lower pollutant concentration and higher wind speed near the ground compared to medium and densely packed cubes. Air quality was improved in closely packed cubes with staggered layout but did not show any improvement in medium and loosely packed cubes with staggered layout. Adversely, disposition of cubes exhibited lower wind speed compared to regular cubes for all street gap sizes. This paper also illustrates a practical strategy in optimising building layouts for wind flow enhancement and air quality improvement in an idealised urban area

Application of geophysical technique in investigation of groundwater quality at Melaka Tengah, Malacca

A study on 2D geo-electrical resistivity imaging at Melaka Tengah, Malacca was conducted to determine the potential groundwater zone. This investigation is needed to identify the quality of the groundwater, since the site is located in the coastal areas where groundwater influence tends to diminish due to intrusion of seawater. Two resistivity lines were proposed with length of 400m each by using Terrameter SAS 4000 and ES1064. Geo-electrical of electrical resistivity and induced polarization method with the Wenner-Schlumberger configuration were carried out. The Res2Dinv software would then render the 2D resistivity image through inversion method which provided detailed information of both the laterally and vertically geological structures based on their part. The electrical resistivity measured the resistance of the subsurface to the flow of electric current in units of ohmmeters and value of chargeability during the transient decay of the applied voltage in ms for induced polarization. Well data provided was very useful in direct determination of subsurface soil lithology. The result obtained showed an 84.7-meter subsurface depth for both areas which then reflected that the subsurface consisted of two different layers namely overburden (laterite, clay, and/or peat soil) with ranged 1 ohm.m – 10 ohm.m and 50 ohm.m – 500 ohm.m for schist formation. However, this area was considered to be brackish water area because of the low chargeability value of 0ms – 1ms especially in top soil layer and 5ms – 20ms for schist formation. Thus, this area was deemed not suitable for groundwater exploration due to the intrusion of salt water

Exploring terrain indices and slope morphometry for trail and campsite planning on Mount Irau, Malaysia

Terrain analysis and elevation profiling are widely utilized in geographical studies where spatial information system is one of the foremost tools in assessing characteristic patterns of hiking trails and plain areas suitable for a campsite. The main objective of this study is to classify the landforms of Batu Gangan Forest Reserve by conducting a morphometric analysis of the digital terrain model (DTM) with a 10 m resolution. The classification process is based on calculating the topographic position index (TPI). Using TPI, the landscape was classified into slope position and landform categories. The delivered TPI landform classes are spatially correlated with the elevation, slope, LS factor, and topographic wetness of the mountain. Site observation was carried out to identify water sources, viewpoints, and their significance as suitable campsites and potential trails. An alternative trail was proposed to reduce the visitor impacts towards the main trail. The result suggested that the plains landform only covered 3.26% or 2.03 km2 of the study area, where two potential campsites were identified. The method presented and research findings derived from the study are beneficial to support sustainable recreation resource planning, especially in a complex mountainous area. The study's findings and data will lead to proper forest use for recreational reasons consistent with conservation efforts

Sonication Time Effect towards Stability of Al2O3/PAG and SiO2/PAG Nanolubricants

Ultrasonication is the act of applying sound force to agitate particles in a sample with the frequency of more than 20 kHz. It is an external vibration induced during preparation of nanolubricant that helps the particles to overcome the van der Waals force bonding. Nanolubricant prepared is intended to be used in automotive air conditioning (AAC) system to improve its performance. In this work, stability Polyalkylene glycol (PAG) and SiOi/PAG nanolubricants of 0.2 % volume concentrations with different sonication lime were investigated. Five samples for each nanolubricant were prepared by two-step method process with variation of sonication time from zero to two hours' time with half an hour interval. The stability tests were done by visual sedimentation and UV-vis spectrometer. The optimum sonication time found to be one and half hours and two hours for AI2O3/PAG and SiOi/PAG nanolubricants respectively. Both nanolubricants were found stable for more than two weeks 'period

Plastic optical fibre sensor for spine bending monitoring

peer-reviewedThis paper presents a study on the application of plastic optical fibre for spine bending monitoring based on an intensity modulation. The bending angle is measured as the angle between the emitting and receiving fibres is changed. The measured light attenuation is compared with a theoretical evaluation and the differences between these values are discussed. It was found that the light attenuation for the light intensity agreed well (margin of error < 15%) with the theoretical value for the range between 180o (representing no bend) and 200o and it was significantly increased for the bending angle beyond that value due to the effect of fibre gap increment which resulted in a less reliable experimental estimation.PUBLISHEDpeer-reviewe