The integration of communication technologies such as radio frequency identification (RFID), global positioning system (GPS), general packet radio system (GPRS), and geographic information system (GIS) with a camera are constructed for solid waste monitoring system. The aim is to improve the way of responding to customer's inquiry and emergency cases and estimate the solid waste amount without any involvement of the truck driver. The proposed system consists of RFID tag mounted on the bin, RFID reader as in truck, GPRS/GSM as web server, and GIS as map server, database server, and control server. The tracking devices mounted in the trucks collect location information in real time via the GPS. This information is transferred continuously through GPRS to a central database. The users are able to view the current location of each truck in the collection stage via a web-based application and thereby manage the fleet. The trucks positions and trash bin information are displayed on a digital map, which is made available by a map server. Thus, the solid waste of the bin and the truck are being monitored using the developed system.
Specific attenuation is the fundamental quantity in the calculation of rain attenuation for terrestrial path and slant paths representing as rain attenuation per unit distance (dB/km). Specific attenuation is an important element in developing the predicted rain attenuation model. This paper deals with the empirical determination of the power law coefficients which allow calculating the specific attenuation in dB/km from the knowledge of the rain rate in mm/h. The main purpose of the paper is to obtain the coefficients of k and α of power law relationship between specific attenuation. Three years (from 1st January 2006 until 31st December 2008) rain gauge and beacon data taken from USM, Nibong Tebal have been used to do the empirical procedure analysis of rain specific attenuation. The data presented are semi-empirical in nature. A year-to-year variation of the coefficients has been indicated and the empirical measured data was compared with ITU-R provided regression coefficient. The result indicated that the USM empirical measured data was significantly vary from ITU-R predicted value. Hence, ITU-R recommendation for regression coefficients of rain specific attenuation is not suitable for predicting rain attenuation at Malaysia.
Gahnite (zinc aluminate) nanoparticle powder is synthesized by a sol-gel method and used to fabricate a microstrip antenna. X-ray diffraction analysis indicates the formation of a face-centered cubic gahnite structure with an average crystallite size of 19.92 nm. The surface morphology of the gahnite is analyzed with field-emission scanning electron microscopy. The presence of water molecules and nitrates within the material is confirmed by Fourier transform infrared analysis. The measured dielectric constant, bandgap and unloaded quality factor of the synthesized powder are 8.70, 4.08 eV and 4592, respectively. The performance of the microstrip antenna is evaluated using return loss, (S11) parameter analysis. The measured impedance bandwidth is 760 MHz in the lowfrequency band and 8.1 GHz in the high-frequency band. The overall performance demonstrates that the fabricated ceramic is suitable for application in a microstrip antenna. Graphical Abstract
A solgel method was used to prepare Ca x Zn (1Àx) Al 2 O 4 thin films and fabricate GPS patch antennas. The addition of calcium (Ca) has increased the e r , crystallite size, and grain size, to increase the ceramics density. The three highest Q 9 f values appear at the position of x = 0.05 (31,091 MHz), 0.15 (63,906 MHz), and 0.25 (40,609 MHz), respectively. The best combination of microwave dielectric properties (e r~9 .02), Q 9 f~63,906 MHz and with the lowest return lost (À25 dB) is obtained for specimen using Ca 0.15 Zn 0.85 Al 2 O 4 (x = 0.15) ceramics, which is the suggested material for GPS patch antennas.
Solid oxide fuel cells (SOFCs) offer high energy conversion, low noise, low pollutant emission, and low processing cost. Despite many advantages, SOFCs face a major challenge in competing with other types of fuel cells because of their high operating temperature. The necessity to reduce the operational temperature of SOFCs has led to the development of research into the materials and fabrication technology of fuel cells. The use of composite cathodes significantly reduces the cathode polarization resistance and expands the triple phase boundary area available for oxygen reduction. Powder preparation and composite cathode fabrication also affect the overall performance of composite cathodes and fuel cells. Among many types of cathode materials, lanthanum-based materials such as lanthanum strontium cobalt ferrite (La 1-x Sr x Co 1-y Fe y O 3-δ ) have recently been discovered to offer great compatibility with ceria-based electrolytes in performing as composite cathode materials for intermediate-to low-temperature SOFCs (IT-LTSOFCs). This paper reviews various ceria-based composite cathodes for IT-LTSOFCs and focuses on the aspects of progress and challenges in materials technology.
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