Enhanced Cooling of Laptop Computer for Improvement of Processing Performance

A major problems in the operation of laptop computers is overheating since it can affect the performance and stability, sometimes leading to system crash and hardware fatality. The objective of this work was to study the thermal behavior inside a laptop computer and to test the effectiveness of aproposed cooling method to overcome overheating problem. The proposed cooling system contained a thermoelectric device that reduced the intake air temperature into the laptop internal cooling system. An external exhaust blower, located at the exhaust air outlet of the laptop, was mounted to ensure sufficient air flow rate delivered by the cooling system. To assess the effectiveness of the system, temperatures of critical components in the computer were measured. It was found from the study that, under extreme utilization situation, the temperature of the graphic processing unit could increase to 99B0;C. The proposed cooling system could bring down the temperature by up to 6B0;C

Low and Medium Calorific Value Gasification Gas Combustion in IC Engines

Higher hydrogen to carbon ratio of gasification gases produced from solid fuels has been utilized in internal combustion engines (ICE) since long ago. Advancements in the conversion technologies and the abundant availability of solid fuels added with advancements in the technology of gas engines and their fuelling system have renewed the interest and are believed to be transition fuels from carbon based to hydrogen based. Over the past 30 years, there were many trials to bring back the gasification gas technology in ICE. This study is mainly focused on the investigation of technical challenges with lower and medium calorific value gasification gases in IC engines The range of operation of these fuels is found to be influenced by available injection duration and injector pulse width in direct-injection spark-ignition engines. The lower calorific value of these gases also make them less competitive to CNG and H2 in the dual fueling in CI engine even though they have better advantage in the emissions. Furthermore, red glow color deposit was spotted on the surface of the combustion chamber after short running on all fuels that was resulted from decomposition of iron pentacarbonyl (Fe(CO)5) contaminants

On the Diversification of Feedstock in Gasification of Oil Palm Fronds

Co-gasification of biomass can be beneficial since relying on only one type of biomass can interrupt operations if the supply of feedstock is disrupted for any reason. Despite this a gasifier system is usually designed for operation with only one specific feedstock. The gasifying of different biomasses can lead to failure or inefficiency. In this work the gasification of different forms of feedstock derived from oil palm frond was tested in an updraft gasifier that was specially designed for oil palm fronds. The feedstocks considered were dried frond blocks, briquetted fronds and overdried (at 150°C) frond blocks. The air flow rate was maintained to the value set for dried fronds in order to investigate the robustness of such configurations. The resulting syngas from the gasification was analyzed in terms of the composition of combustible gases and higher heating value (HHV). Overall, it was found that the altered forms of feedstock caused degradation in the syngas quality, which resulted in a decrease in the HHV of up to 65%

Groundwater resources assessment using integrated geophysical techniques in the southwestern region of Peninsular Malaysia.

Combined geophysical techniques such as multi-electrode resistivity, induced polarization, and borehole geophysical techniques were carried out on volcano-sedimentary rocks in the north of Gemas as part of the groundwater resource’s investigations. The result identifies four resistivity units: the tuffaceous mudstone, tuffaceous sandstone, the tuff bed, and the shale layer. Two types of aquifer systems in terms of storage were identified within the area: one within a fracture system (tuff), which is the leaky area through which vertical flow of groundwater occurs, and an intergranular property of the sandy material of the aquifer which includes sandstone and tuffaceous sandstone. The result also reveals that the aquifer occupies a surface area of about 3,250,555 m2 with a mean depth of 43.71 m and a net volume of 9.798 × 107 m3. From the approximate volume of the porous zone (28 %) and the total aquifer volume, a usable capacity of (274.339 ± 30.177) × 107 m3 of water in the study area can be deduced. This study provides useful information that can be used to develop a much broader understanding of the nature of groundwater potential in the area and their relationship with the local geology

Methane Enrichment of Syngas (H2/CO) in a Spark-ignition Direct-injection Engine: Combustion, Performance and Emissions Comparison With Syngas and Compressed Natural Gas

Syngas produced from gasification of solid fuels can serve best as transition fuel from the carbon-based to the hydrogen-based fuels in the internal combustion engines. The lone drawback is its low calorific value being between one tenth and one fifth of that of CNG (Compressed Natural Gas). This results in higher BSFC (brake specific fuel consumption) and limitation on the injection duration at late injection timings in the DI (direct-injection) SI (spark-ignition) engine. Recently, there have been efforts to enrich the syngas with methane so that the calorific value can be improved. This paper presents experimental results on the effect of methane-enrichment of syngas on the combustion, performance and emissions in the DISI engine. The result shows that the MES (methane-enriched syngas)(has extended the operation excess air ratio (λ) compared to syngas and CNG at the same engine speed. Methane-enrichment has maintained the faster and smoother combustion, the lower brake emissions of carbon monoxide and total hydrocarbon, and higher brake emissions of nitrogen oxides observed with syngas. Besides, MES improved the maximum brake thermal efficiency and the BSFC of the syngas by 30.2% and 21.3%, respectively. Therefore, MES can be better replacement to CNG in the DISI engine at all load conditions

Effect of Blending Ratio on Quality of Producer Gas From Co-Gasification of Wood and Coconut Residual

Biomass gasification often encounters the shortage of biomass supply for continuous operation. Co-gasification of different biomass materials is a promising solution that can address the shortage of biomass supply for the continuous gasification process. However, the effectiveness of co-gasification is not well understood. Furthermore, there is nearly no reported work of co-gasification of two or more biomass materials. In this study, two Malaysian local biomass materials, wood residual and coconut shells were co-gasified in a 33.6 kW thermal capacity downdraft gasifier to investigate the effect of blending ratio the on quality of the producer gas. The results show that producer gas composition increased as coconut shells proportion increased in blends of up to 60%. A blend of 40:60 W/CS results in a synergetic effect as compared to discrete gasification of both feedstock. The maximum H2 and CO were obtained as; 11.46 vol.% and 23.99 vol.% respectively at 40:60 W/CS blending ratio. The results achieved from 40:60 W/CS blend were 16.70% and 10.96% higher as compared to pure wood gasification for H2 and CO respectively. It is concluded that coconut shells can be utilized a substitute of wood residual in form of blends or as discrete feedstock for the continuous gasification process without the change in gasifier geometry

Syngas (H2/CO) in a Spark-Ignition Direct-Injection Engine. Part 1: Combustion, Performance and Emissions Comparison with CNG

The combustion, performance, and emissions of syngas (H2/CO) in a four-stroke, directinjection, spark-ignition engine were experimentally investigated. The engine was operated at various speeds, ranging from 1500 to 2400 rev/min, with the throttle being held in the wide-open position. The start of fuel injection was fixed at 180�before the top dead center, and the ignition advance was set at the maximal brake torque. The air/fuel ratio was varied from the technically possible lowest excess air ratio (l) to lean operation limits. The results indicated that a wider air/fuel operating ratio is possible with syngas with a very low coefficient of variation. The syngas produced a higher in-cylinder peak pressure and heat-release rate peak and faster combustion than for CNG. However, CNG produced a higher brake thermal efficiency (BTE) and lower brake specific fuel consumption (BSFC). The BTE and BSFC of the syngas were on par to those of CNG at higher speeds. For the syngas, the total hydrocarbon emission was negligible at all load conditions, and the carbon monoxide emission was negligible at higher loads and increased under lower load conditions. However, the emission of nitrogen oxides was higher at higher loads with syngas

Study on Co-Gasification of Oil Palm Fronds and Wood

Over the decade, gasification experiment on different biomass materials has been carried out to investigate the biomass potential as one of the alternative sources of fuel. Although gasification has been proven to be successful in bringing out the potential of different biomass fuels, it commonly involves conversion of only one type of biomass materials for a single run. This paper discusses the co-gasification experiment of different composition of oil palm fronds (OPF) and wood using a downdraft gasifier. The conducted study focuses on the temperature profile within the reactor and also the characteristic of the dynamic temperature profile in each zone within the gasifier reactor. The temperature profile in the drying, pyrolysis, oxidation and reduction zone of the reactor was experimentally investigated. Effect of bridging on the temperature profile is also observed. The temperature profiles obtained are compared with literature result. In addition, syngas production was monitored by observing the flare produced during the operation. However, further experiment need to be done to investigate the composition of syngas produced during the co-gasification experiment