Optimization Of Wireless Pricing Scheme

The wireless service providers obtain surplus fromconsumers who applied the service. That pricing strategyis developed by considering the linearity factors, elasticityprice, price factors, acceptance factor and unit serviceprice. Previous researches are focussed on the introductionof the models in general. This new approach of the modelis by considering the model as the nonlinear programmingproblem that can be solved optimally using LINGO 13.0.The optimal solution could give information on decisionvariables and objective function to maximize the revenuefor the providers. The several objectives to be achieved byservice providers are by setting the increment ordecrement of price change due to QoS change and amountof QoS value

Design and development of plasma antenna for wi-fi application

The term plasma is often referred to as the fourth state of matter. When sufficient ionized, plasma can be a conductor element. Plasma antenna is a type of radio antenna that represents the use of ionized gas as a conducting medium instead of metal conductors. The main objective in this research is to design plasma antenna at 2.4 GHz by using commercial fluorescent tube. In this work the commercial fluorescent lamp was chosen because it was low cost to produce plasma element. The plasma antenna in this research was made from fluorescent lamp that functioned as a radiating element with target frequency at 2.4 GHz for Wi-Fi application. The commercial fluorescent lamp consisted of argon gas and mercury vapor with a diameter of 28 mm and a length 589.8 mm. The result showed that a fluorescent tube, can be used to work as a plasma antenna for Wi-Fi application.Keywords: plasma antenna; plasma element; coupling sleeve; Wi-fi applicatio

Influence of oil palm empty fruit bunch (OPEFB) agro-waste properties as filtration medium to improve urban stormwater

Oil palm empty fruit bunch (OPEFB) is recommended as a filtration medium due to its fibrous characteristics and abundance as an agricultural byproduct. OPEFB is utilized to treat urban stormwater using a deep bed filter column. Urban stormwater samples were collected from Sembulan River, which flows through the Kota Kinabalu city area of Sabah, Malaysia. The samples were filtered through single and combination designs of OPEFB and river sand (RS) in mix ratios ranging between 25-75%. Each design’s performance was evaluated in terms of Total Suspended Solid (TSS), turbidity, colour, temperature, Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD), and Ammoniacal nitrogen (NH3-N) removal. Single medium designs demonstrated the poorest performance compared to dual mediums design. The optimum mixed design was 50:50 with ability to remove 52% color, 49% turbidity, 44% TSS, 59% COD, 84% BOD, and 94% NH3-N. Further OPEFB water-washing treatment followed by a backwashing process achieved better separation results than a straightforward maintenance process. The optimized dual-filtration of stormwater was able to increase the urban stormwater quality from Class III up to Class I according to the Malaysian Interim National Water Quality Standard (INWQS), thus classified as suitable for water supply and conservation for natural environment uses

Hepatitis C Virus Prevalence in Haemodialysis Patients From Three Centers in Baghdad, Iraq: A Survey By Polymerase Chain Reaction and Serological Methods

Hepatitis C virus infection is a major health problem among haemodialysis patients in developing countries. Nosocomial transmission of HCV infection was a considerable route, particularly during the outbreaks of infection. To compare serological and molecular methods for detection of HCV infection serum samples were screened for anti-HCV antibodies using a fourth generation enzyme-linked immunosorbent assay (ELISA) and positive samples were confirmed by immunoblot assay. All seropositive and seronegative samples were screened for the presence of HCV-RNA by using reverse transcriptase PCR (RT-PCR). The overall prevalence was (41.10%) in the three centers (range: 26.05% to 62.82%) with higher prevalence in Al-Kadhimiya Teaching Hospital. All seropositive samples were tested by reverse transcriptase PCR, and 24/92 (26.09%) of confirmed samples were found to contain HCV-RNA. Additionally, 2/5 (40%) of immunoblot-indeterminate and 1/3 (33.33%) of immunoblot-negative samples were also found to be HCV-RNA positive. Also all seronegative samples were screened for the presence of HCV-RNA by using pooling strategy and 2/136 (1.47%) of anti-HCV negative samples were found to be HCV-RNA positive. Our data emphasize the need for stricter adherence to infection control measures in haemodialysis centers and reinforce the importance of screening by both PCR and serological methods at regular intervals to identify all HCV-infected patients.en

The Implicit Keller Box method for the one dimensional time fractional diffusion equation

Abstract There are a number of physical situations that can be modeled by fractional partial differential equations. In this paper, we discuss a numerical scheme based o

Polyetherimide hollow fiber membranes for CO2 absorption and stripping in membrane contactor application

Porous asymmetric polyetherimide (PEI) hollow fiber membranes with various non-solvent additives, e.g. lithium chloride, methanol and phosphoric acid (PA) were prepared for CO2 absorption and stripping process in a membrane contractor. The PEI membranes were characterized via gas permeation, liquid entry pressure of water (LEPw), contact angle and field emission scanning electronic microscopy analysis. The CO2 absorption and stripping performance was evaluated via the membrane contactor system. Addition of non-solvent additives increased the LEPw and membrane porosity of the PEI membrane with the formation of various membrane microstructures and contact angles. Absorption test was performed at 40 °C showed that the PEI-PA membrane produced the highest absorption flux of 2.7 × 10-2 mol m-2 s-1 at 0.85 m s-1 of liquid velocity. Further testing on PEI-PA membrane was conducted on CO2 stripping at 60 °C, 70 °C to 80 °C and the results indicated that the stripping flux was lower compared to the absorption flux. Stripping tests at 80 °C produced the highest stripping flux which might due to the increase in equilibrium partial pressure of CO2 in the liquid absorbent. Modification of PEI membrane via incorporation of additive can enhanced the performance of a membrane contactor via increasing the absorption and stripping flux

Evaporation lifetime and boiling curve on hemispherical stainless steel (304) surface

The purpose of this research is to study and investigate the evaporation lifetime and boiling curve on a hemispherical heated surface. The selected material was stainless steel (304). A nearly perfect and smooth hemispherical surface was developed by using EDM die sinker. For the test liquid, distilled water was used during the experimental work. The average droplet temperature was 31.36 °C corresponding to liquid subcooling ∆Tsub = 68.64K. Based on the theoretical calculation, the diameter of the water droplet was approximately 5.00 mm. Meanwhile, the impact height was approximately 65.0 mm corresponding to the theoretical impact velocity of 1.129 m/s. The material was heated using a digital hot plate which was able to give an accurate reading and stable temperature fluctuation during the heating process. The temperature ranged from a low temperature of Tw = 100 °C to a high temperature of Tw = 300 °C. As a result, the boiling curve showed a similar pattern of other experimental work that consists of two (2) important points which are the Critical Heat Flux (CHF) and Leidenfrost temperature

Point Absorber Method as Wave Energy Convertor Device for Power Generation: Effect of Buoy Arrangements

A point absorber is a floating structure with components that move relative to each other due to wave action. They utilize the up and down movement of the wave height at a single point for energy conversion. The relative up and down which is bobbing motion caused by passing waves used to drive electromechanical energy converters to generate power output. This experiment investigates behaviour of the point absorber device used the pneumatic sensor to take the frequency of the displacement of buoy while testing in the wave maker generator. Then, study the efficiency power output of point absorber WEC device and studies the behaviour of the point absorber in a regular wave. Fabricate the linear generator which as power absorption to estimate the effectiveness power output on different configuration by using the multimeter device. The point absorber at the front position of the configuration has good behaviour because of the high frequency produced. By estimated the behaviour of the device on configuration achieved. Configuration shape design of the point absorber used in this testing is square, diamond and parallelogram shape for an estimate the best power output. The configuration of the parallelogram has the best power output compared to another configuration. The best arrangement of the device for efficiency by measure the output voltage as power output is 68.14 mV and increase 8% in every minute

Design, development and performance evaluation of a large-scale hybrid solar dryer

A large-scale hybrid solar dryer was developed to account the limitations encountered in traditional open sun drying. With loading capacity of 500 kg and incorporated with a hybrid heating control system, this dryer is suitable for industrial drying that requires large drying capacity and products with high moisture content. In addition, this drying system offers flexibility in switching between different combinations of air vents based on the drying purpose required. Chaotic air flow produced in the drying chamber ensure uniform temperature distribution across the drying trays in an updraft air movement. Potential application of the drying system for durian skin and chili drying were tested. Based on the performance evaluation, a maximum temperature and maximum average temperature of 66°C and 59°C, respectively, was attained in the drying chamber. The drying of chilli with the drying temperature set at 50°C and operating condition of using the ventilation fan and opening the air vent achieved the drying time of 5 days or 45 hours in total, equivalent to 9 hours of drying time per day