680 research outputs found
Power Consumption Modeling and Analysis of Integrated Optical-Wireless Access Network
The integration of optical and wireless technologies at access networks are considered as a future solution which provide both high bandwidth and high mobility in an efficient way. GPON is a suitable candidate for optical backhaul due to the combination of higher data rates, greater split ratio and support for triple play services hence it offers maximum flexibility and cost advantages. On the other hand, recent developments of new radio access technologies and introduction of femtocell base stations provide the potential of offering broadband services and applications to everyone and everywhere. However, the power consumption of this network demands a particular attention because access networks are the largest contributor the network related electricity consumption. Therefore, in this paper we evaluate the power consumption of integrated optical-wireless access network which is based on independent ONU-BS architecture. We proposed a power consumption model for such network and the assessment has been done under different simulation scenarios. The constructed model will provide insight of the energy performance of the integrated access network so that in the network design process, focus can be done to the most energy saving strategies
Kesan penambahan limonena terhadap mikroemulsi asid oleik/Cremophor rh 40/Transcutol/Air
Gambar rajah fasa pseudo-ternari sistem mikroemulsi asid oleik/Cremophor rh 40/Transcutol/Air diperoleh melalui pentitratan air pada nisbah surfaktan:kosurfaktan (Km) yang berbeza. Nisbah optimum bagi surfaktan/kosurfaktan adalah Km=2:1. Kesan penambahan limonena sebagai fasa minyak campuran terhadap sistem mikroemulsi diuji pada nisbah limonena:asid oleik (1:1, 2:1 dan 3:1). Penambahan limonena berupaya menghasilkan rantau mikroemulsi yang lebih besar sehingga 70%-80 % bt. air bagi kesemua nisbah limonena:asid oleik. Nisbah limonena:asid oleik (1:1) memberikan rantau mikroemulsi yang paling luas pada nisbah minyak:surfaktan/kosurfaktan (Minyak:S/KoS=1:9). Sifat isotropik mikroemulsi ditentukan dengan menggunakan mikroskopi cahaya polarasi. Mikroemulsi dibangunkan pada nisbah Km=2:1 dan Minyak:S/KoS (1:9) serta limonena:asid oleik (1:1). Kestabilan dan saiz partikel bagi sistem dikaji dan penambahan limonena didapati tidak merubah sifat serta mikro-struktur sistem mikroemulsi. Kajian konduktiviti elektrik dan kelikatan sistem menunjukkan pembentukan mikroemulsi jenis air-dalam-minyak (10% dan 20 % bt. air) dan dwiselanjar (30%-50 % bt. air). Kesemua sistem mempunyai potensi sebagai sistem penghantar bahan aktif dan menunjukkan kestabilan yang baik pada suhu 4, 25 dan 37°C dalam tempoh lebih daripada 6 bulan
Image Reconstruction Validation for CMOS Linear Image Sensor Based Tomography System
Nowadays, the fast-moving industries need a low cost, accurate, low power consumption, non-invasive and safe method for monitoring and tracking of the conveying and manufacturing process. There is many tomography based systems available in the industry, however, with limitations. This project aims to solve industrial problems of monitoring objects inside a transparent conveying pipe and determine the characteristic of the objects such as size, quantity and position. This is done through the image reconstruction of data acquired from Complementary metal-oxide-semiconductor (CMOS) linear image sensor based on optical tomography system. Data from four projections of laser are used to avoid the aliasing problem that may occur due to fewer projections. The image can be reconstructed by using linear back projection technique. The image will undergo image processing to enhance the image for better visualization of the object. Theoretical and experimental image are compared to validate the image reconstruction. As a result, the position, size and number of a symmetrical and solid object can be determined accurately from the reconstructed image. For further improvement, the number of projection may be increased
The influence of surfactant/co-surfactant hydrophilic-lipophilic balance on the formation of limonene-based microemulsion as vitamin C carrier
This research was conducted to produce a limonene-based microemulsion system as vitamin C carrier. The microemulsion was produced using limonene as the oil phase, tween20 and tween80 as surfactants while propylene glycol, polyethylene glycol 400 and glycerol as co-surfactants. Pseudo-ternary phase diagrams were constructed to determine the microemulsion area by using the water titration method at 25°C. The effect of hydrophilic-lipophilic balance (HLB) value of the mixture of S/CoS on the formation of limonene-based microemulsion was studied. The HLB value calculated for the mixture of tween20/propylene glycol in the different ratio was between 10.1 and 13.4. From the experiment, the preparation of limonene-based microemulsion system with tween20/propylene glycol was able to provide large and high stability of microemulsion region on ternary phase diagram (23.6%) while higher HLB value resulted in larger microemulsion area in ternary phase diagrams. The sole formulation with propylene glycol was further selected to carry out the physicochemical characterization of system’s stability, particle size and electrical conductivity. All microemulsion systems showed good stability for four weeks at temperature of 4, 25 and 40°C without any phase change and separation. Particle size characterization results elucidated that all microemulsion systems consisted particle size between 20 and 100 nm. The study of electrical conductivity showed that water-in-oil microemulsion was formed from 5-45% wt. of water whereas bicontinuous microemulsion was formed from 50-90% wt. of water content. Overall, the result showed that microemulsion tween20/propylene glycol/limonene/water was potential as a carrier system of vitamin C
Design of graphic and animation in game interface based on cultural value: verification
No AbstractKeywords: game interface; cultural value; hofstede; prototype; eye tracke
Thermo-kinetic assessment of glucose decomposition to 5-hydroxymethyl furfural and levulinic acid over acidic functionalized ionic liquid
Decomposition of biomass feedstock is a promising technique for producing versatile chemicals such as 5-hydroxymethyl furfural (5-HMF) and levulinic acid (LA). Glucose, the model compound of cellulose, is one of the most important starting components for bio-based chemical synthesis. Herein, the kinetics of glucose decomposition catalyzed by an acidic functionalized ionic liquid, 1-sulfonic acid-3-methyl imidazolium tetrachloroferrate ([SMIM][FeCl4]) was studied in the temperature range of 110–170 °C. A simplified kinetic model was developed based on pseudo-homogeneous first-order reactions. The kinetic model consists of four main key steps: (1) dehydration of glucose to 5-HMF; (2) degradation of glucose to humins; (3) rehydration of 5-HMF to LA; and (4) degradation of 5-HMF to humins. The proposed model was in a good agreement with the experimental results. The evaluated activation energies for glucose decomposition to 5-HMF and 5-HMF decomposition to LA were 37 and 30 kJ·mol-1, respectively. The first-order rate constants were also used to calculate the thermodynamic activation parameters. The kinetic and thermodynamic parameters obtained can be applied to provide insights on the biomass decomposition to 5-HMF and LA using acidic ionic liquid
Landslides and lineament mapping along the Simpang Pulai to Kg Raja highway, Malaysia
Geological structural features, such as the discontinuities that may be detected on satellite imagery as lineaments, in many cases control landslide occurrences. Lineament may represent the plane of weakness where the strength of the slope material has been reduced, eventually resulting in slope failure. The main objective of this study is to assess the relationship between lineament and landslide occurrences along the Simpang Pulai to Kg Raja highway, Malaysia. Lineament mapping was undertaken utilizing Landsat imagery and landslide distributions were identified based on field mapping and historical records. Lineament density maps of length, number and intersections were generated and compared with landslide distributions. The lineaments were also visually compared with the landslide occurrences. The results showed that there is an association between the lineaments and landslide distribution. Thus, lineament mapping is essential for the early stages of planning to prevent hazard potential from landslides
The application of green roof for stormwater quantity and quality improvement
The use of green roof is becoming increasingly worldwide because of its environmental, economic, and aesthetic benefits. The ability to retain storm water and improve the quality of effluent flow are the important characteristics of green roof. It is viewed as a best technology to minimize the negative impact of urbanization. However, the application of green roof in Malaysia is less and literatures regarding these is limited. An attempt has been made to evaluate the performances of green roof in improving the water quantity and quality of stormwater runoff. A lab-scale green roof with five component layers which are vegetation layer using creeping ox-eye and beach morning glory, topsoil substrate layer, non-woven geotextile filter layer, drainage plate layer and liquid waterproofing layer was used. Results indicated that the green roof with creeping ox-eyes shows a better performance in reducing peak flow with as high as 41% percentages of reduction compared to beach morning glory (15%). On the other hand, the green roof with beach morning glory manage to improve the concentration of COD up to 99% improvement while the green roof with creeping ox-eye shows a better performance in improving BOD with 17% reduction
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