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An automotive air conditioning system that uses thermal expansion valve (TEV) as an expansion device. The pressure drop from the condenser and evaporator pressure is considered an isenthalpic process (constant enthalpy), where this process causes energy loss (entropy generation) in the expansion process. The ejector recovers energy losses, which was previously lost in the expansion valve, and an ejector can be used to generate isentropic condition in the expansion process. The use of an ejector as an expansion device in this study can reduce power consumption of the compressor and increase cooling capacity of the evaporator. The experiments were conducted with temperature set-points of the conditioned space of 21, 22 and 23°C with internal heat loads of 100, 200 and 400 W. Measurements were taken during the one hour experimental period at a time interval of five minutes. The experiment results indicate that the ejector system is better than TEV and save fuel.

An air conditioning (AC) system design requires two main aspects that should be taken into consideration, there are reducing energy consumption and ensuring thermal comfort. This paper present variable speed drive on compressor motor is being tested to reduce the energy consumption. Conventional AC system to use on/off controller where the compressor motor turns itself on and runs at maximum speed then turns back off to achieve the temperature setting. This controller consumes more energy, however, by using a variable speed drive, the compressor motor will constantly run at various speeds while achieving the temperature setting. A system that developed software to implement the controller algorithms was installed in a thermal environmental room with data acquisition to monitor the room temperature, energy consumption, energy saving and coefficient of performance. Measurements were taken during the one hour experimental period at a time interval of three minutes for temperature set-points of 22, 23 and 24°C with internal heat loads of 500, 700 and 1000 W. The proposed technique can save energy and thermal comfort in comparison with conventional on/off control. The experiment results indicate that the application of variable speed drive on compressor motor is better than conventional on/off.

In this research, a physico-chemical treatment method of coagulation-flocculation process is implemented in treating partially stabilized leachate from Matang Landfill, Perak, Malaysia. Central composite design has been used to optimize the independent variables namely polyaluminum chloride (PAC) coagulant dosage (A), rapid mixing speed (B) and rapid mixing time (C). The experimental results were analyzed by using analysis of variance (ANOVA). The results revealed that the percentage of color and COD removal was found increased by increasing rapid mixing speed with optimum removal of 95 % and 56 % respectively. Besides, the R-squared values implied that 86.22 % and 97.34% of the total variation explained by the model equation. Furthermore, the model analysis revealed that rapid mixing speed were significant for removal of color and COD through single parameter (B) and interaction between parameter (AB) respectively. This finding proves the influence of mixing parameter in coagulation-flocculation process for leachate treatment.

Coagulation and flocculation are two of the most common chemical treatment methods used in leachate treatment. Existing coagulants are mainly based on Al and Fe salts. The use of non-chemical based coagulants, especially natural polymers, in leachate treatment has not been thoroughly investigated. Natural coagulants have less harmful effects to human health compared with metal salts. This study aimed to investigate the effectiveness of ferric chloride (FeCl3) and chitosan as coagulant in removing the turbidity and color from landfill leachate. Leachate was collected from the Matang Landfill site located at Taiping, Perak, Malaysia. When used as the main coagulant in this study, FeCl3 was able to remove 97.78% of the turbidity and 95.54% of the color of the leachate at an optimum dosage of 3600 mg/L. At a dosage of 60 mg/L, chitosan only removed 23.52% of the turbidity and 14.67% of the color at pH levels of 9 and 4, respectively. The optimum pH value for FeCl3 was 6. Therefore, FeCl3 is an effective coagulant that can help to remove the colour and turbidity compared to chitosan.

This article reviewed selected works on how decision makers (DMs) utilize integrated geographic information system (GIS)/analytical hierarchy process (AHP) tools to analyze land suitability for sanitary landfill sites as part of regional planning. We analyzed the hierarchy process of certain pervious works to facilitate better understanding. The innovative work of Siddiqi et al. in 1996 highlighted the advantages of integrating AHP in GIS software and reviewed some limitations. The present paper explained the background study on multi-criteria decision analysis/aid (MCDA) so-called multi-criteria decision makers (MCDM) in conjunction with the advantages of GIS as a new remedy for utilizing the AHP weights of the decision makers. For this study we often use the term MCDA and MCDM.

Parking a car under the hot sun with all windows closed could increase in-cabin temperature as high as 70oC. For such situation, human occupancy will exposed to thermal shock and inconvenience when embarking the vehicle. Another concerned of this accumulated heat gain is the effect of gas emitted by the interior material which mostly is made of vinyl. These experimental studies try to look the possibilities of bringing down the temperature and hence to suit human habitation. In this study, two methods were implemented and they are by creating fresh air change and introducing evaporative cooling by generating water mist in the air flow for further enhancement of temperature drop. Fully automated control strategy was used based on in-cabin temperature activation by the assistance of electronic control unit (ECU). Observation was made and compare for original car condition and the one equipped with In-Cabin Ventilation (IVS). The result shows the car cabin temperature can reach as high as 65oC without ventilation. With fresh charged of air and evaporative cooling, temperature drops to a range of 40 to 50oC.

Understanding the characteristic of leachate is important since it has complexity properties because of the variation in its composition. This study, analyzed and compared two leachate from two landfill sites, namely, Matang and Kuala Sembeling landfill. Leachate raw samples were collected by grab sampling and were analyzed for 11 parameters. The average concentrations of MLS and KSLS leachate such as BOD5 (146 and 61 mg/L), COD (828 and 363 mg/L), pH (7.6 and 8), SS (407 and 220 mg/L), ammonia (868 and 367 mg/L) , BOD/COD (0.18 and 0.14), cadmium (0.19 and 0.1 mg/L), cuprum (0.09 and 0.1 mg/L), nickel (0.17 and 0.1 mg/L), manganese (0.09 and 0.22 mg/L), and ferum (2.3 and 8.3 mg/L) were recorded, respectively. The results revealed that the both landfills are categorized as partially stabilized leachate. The strength of leachate pollutants from MLS are higher than KSLS because of the higher fraction of organics concentration. There are 5 parameters (BOD5, COD, ammonia, SS and cadmium) in MLS and 7 parameters (BOD5, COD, ammonia, SS, cadmium, manganese and ferum) in KSLS exceeded the permissible limit stated by MEQA (1974), and so leachates from both landfill sites need a suitable treatment to reduce the concentration of the leachate pollutants before discharge into environment.