On-body antenna wit parasitic elements

An antenna with multi-elements that act together to form an array is required to increase the gain. One example is the well-known Yagi-Uda antenna. Such an antenna is widely used for television communication in which it operates at high frequency (HF), very high frequency (VHF) and ultra high frequency (UHF). It consists of a driven element and a number of parasitic radiators in which currents are induced by mutual coupling. Some applications consider the mutual coupling effect undesirable because it degrades the performance. However, in the parasiticaray it is central to the operation. The parasite elements are useful to increase the gain, create a directional beam and enhance the bandwidth impedance of the antenna

Enabling Mobile Location Based Services for Emergency Cases

Late attention by officers in charge to high volumes of crimes and emergency cases can lead to an increase of unsolved cases nationwide. In this paper, we propose the use of Pull & Push Location Based Service model in experiments of the implementation of Location Based Service environment to lessen the problems faced by Police and Fire Fighters in retrieving accurate information while patrolling high risk area. The time taken and the accuracy of information are problems normally faced by Police and Fire Fighters in Emergency Case department. It is crucial for them to get the right information at the right time to their walkie talkie or mobile phones. We first proposed the usage of RSS as the web services to provide feeds for the smart phone application. Updates on crimes or emergency cases within the users’ locations are sent upon users’ retrieval or push based on the users’ locations. The application is developed by using Eclipse IDE platform and tested using HTC Magic with Android OS. The application flow starts by retrieving the location position and information on emergency cases will then be displayed according to date listed. The conceptual design and architecture are designed for Pull and Push Location Based Services

Methyl esters selectivity of transesterification reaction with homogenous alkaline catalyst to produce biodiesel in batch, plug flow, and continuous stirred tank reactors

Selectivity concept is essential in establishing the best operating conditions for attaining maximum production of the desired product. For complex reaction such as biodiesel fuel synthesis, kinetic studies of transesterification reaction have revealed the mechanism of the reaction and rate constants. The objectives of this research are to develop the kinetic parameters for determination of methyl esters and glycerol selectivity, evaluate the significance of the reverse reaction in transesterification reaction, and examine the influence of reaction characteristics (reaction temperature, methanol to oil molar ratio, and the amount of catalyst) on selectivity. For this study, published reaction rate constants of transesterification reaction were used to develop mathematical expressions for selectivities. In order to examine the base case and reversible transesterification, two calculation schemes (Case 1 and Case 2) were established. An enhanced selectivity was found in the base case of transesterification reaction. The selectivity was greatly improved at optimum reaction temperature (60 C), molar ratio (9 : 1), catalyst concentration (1.5 wt.%), and low free fatty acid feedstock. Further research might explore the application of selectivity for specifying reactor configurations

Methyl esters selectivity of transesterification reaction with homogenous alkaline catalyst to produce biodiesel in batch, plug flow, and continuous stirred tank reactors

Selectivity concept is essential in establishing the best operating conditions for attaining maximum production of the desired product. For complex reaction such as biodiesel fuel synthesis, kinetic studies of transesterification reaction have revealed the mechanism of the reaction and rate constants. The objectives of this research are to develop the kinetic parameters for determination of methyl esters and glycerol selectivity, evaluate the significance of the reverse reaction in transesterification reaction, and examine the influence of reaction characteristics (reaction temperature, methanol to oil molar ratio, and the amount of catalyst) on selectivity. For this study, published reaction rate constants of transesterification reaction were used to develop mathematical expressions for selectivities. In order to examine the base case and reversible transesterification, two calculation schemes (Case 1 and Case 2) were established. An enhanced selectivity was found in the base case of transesterification reaction. The selectivity was greatly improved at optimum reaction temperature (60 C), molar ratio (9 : 1), catalyst concentration (1.5 wt.%), and low free fatty acid feedstock. Further research might explore the application of selectivity for specifying reactor configurations

A New Wideband Circularly Polarized Dielectric Resonator Antenna

A wideband and compact circularly polarized (CP) C-shaped dielectric resonator antenna (DRA) is presented. The proposed C-shaped DR is excited by a simple stripe line connected to a coplanar waveguide (CPW) feeding line. The C-shaped DRA is circularly polarized with 19% axial ratio (AR) bandwidth. It is found that the CP bandwidth can be expanded by using a narrow short circuit strip. The final design achieves CP with 50% AR bandwidth. The proposed circularly polarized DRA (CPDRA) with good radiation characteristics offers an impedance bandwidth of 58% between 3.45 and 6.26 GHz for VSWR ≤ 2. The proposed DRA is fabricated and tested. Very good agreement between simulated and measured results is obtained

Changes in growth, survival and digestive enzyme activities of Asian redtail catfish, Mystus nemurus, larvae fed on different diets

A study was conducted to determine the effects of different dietary treatments on the growth, survival and digestive enzyme activities of Mystus nemurus larvae. Newly hatched larvae were reared for 14 days in twelve 15 L glass aquaria (for growth and survival) and eight 300 L fiberglass tanks (for enzyme samples) at a stocking density of 15 larvae L-1. Beginning at 2 days, the larvae were randomly assigned to Artemia nauplii, a microbound diet and a 50:50 combination of live food-microbound diet, while another group was unfed. All treatments were triplicated (growth and survival) or duplicated (enzyme development). The results showed that, M. nemurus larvae which fed on Artemia nauplii gave the highest survival rate (83.7%), followed by those fed on a combination diet (56.0%) and a microbound diet (26.5%). All unfed larvae did not survive beyond Day 9. Artemia had also given the best growth (20.4 ± 1.4 mm TL and 37.2 ± 6.0 mg wet weight) for the catfish larvae. This was followed by the combination diet (18.3 ± 0.6 mm TL and 32.6 ± 3.4 mg wet weight) and the microbound diet (11.0 ± 0.1 mm TL and 11.9 ± 0.9 mg wet weight), respectively. Pepsin began to significantly appear in M. nemurus larvae at 4 days old for all treatments, while chymotrypsin, trypsin and amylase were present even in the newly hatched larvae. In general, highest enzyme activities were observed among larvae which fed on a combination diet, followed by those fed on live and artificial diets, respectively. This suggested the important role of exogenous enzymes from live food in the larval digestion particularly at the early feeding stages.Key words: Mystus nemurus, Artemia nauplii, larvae, microbound diet, combination diet

Kesan penggunaan koswer multimedia animasi visual terhadap pencapaian pelajar dalam mata pelajaran matematik

Ramai pelajar yang bermasalah dalam topik Pelan dan Dongakan. Ini kerana pelajar sukar untuk membayangkan objek yang tersembunyi melalui proses pengajaran dan pembelajaran (P&P) secara konvensional. Penyelidik telah membangunkan satu koswer multimedia animasi visual dalam topik Pelan dan Dongakan dengan menerapkan kesemua elemen-elemen yang dapat membantu meningkatkan kemahiran visual iaitu elemen animasi, video, audio, grafik dan teks. Seterusnya, kajian kuasi eksperimental ini turut dijalankan bertujuan untuk mengetahui kesan penggunaan koswer multimedia animasi visual terhadap pencapaian pelajar bagi mata pelajaran Matematik di sekolah menengah. Ujian Pra dan Ujian Pos digunakan untuk melihat perbezaan pencapaian yang signifikan selepas menggunakan koswer multimedia animasi visual yang menggunakan teori Kognitif Visual Wiley. Responden yang terlibat dalam kajian ini ialah seramai 40 orang pelajar Tingkatan Lima yang dibahagikan kepada dua kumpulan iaitu kumpulan rawatan dan kumpulan kawalan yang dipilih daripada sebuah sekolah di daerah Batu Pahat, Johor. Hasil analisis menunjukkan peningkatan skor min markah bagi pelajar kumpulan rawatan. Hasil analisis ujian-t (paired-sample-t-test) membuktikan bahawa wujudnya perbezaan skor min markah yang signifikan di antara markah ujian pra dan markah ujian pos bagi kumpulan rawatan. Oleh itu, terdapat perbezaan yang signifikan di antara skor min markah ujian pra dan ujian pos bagi pelajar kumpulan rawatan selepas menggunakan koswer multimedia animasi visual. Manakala instrumen soal selidik yang digunakan untuk melihat tahap penerimaan pelajar selepas menggunakan koswer multimedia animasi visual berdasarkan tiga aspek iaitu aspek isi kandungan, aspek interaksi dan aspek persembahan telah memeperolehi skor min yang tinggi bagi ketiga-tiga aspek tersebut. Dapatan kajian ini menggambarkan penggunaan koswer multimedia animasi visual dapat membantu meningkatkan pencapaian Matematik di dalam bilik darjah terutama yang tidak melibatkan pengiraan

Rice yield classification using backpropagation network

Among factors that affect rice yield are diseases, pests and weeds. It is intractable to model the correlation between plant diseases, pests and weeds on the amount of rice yield statistically and mathematically. In this study, a backpropagation network (BPN) is developed to classify rice yield based on the aforementioned factors in MUDA irrigation area Malaysia. The result of this study shows that BPN is able to classify the rice yield to a deviation of 0.03

Training needs assessment in Malaysia: Exercise held at Kuala Lampur and Kota Bharu from 13th October 1989

Training / Irrigation / Evaluation / Malaysia