Yus Aniza Yusof, Che Rodiziah Md. Noor
Department of Process and Food Engineering,
Faculty of Engineering, Universiti Putra Malaysia,
43400 Serdang, Selangor, Malaysia.
This paper presents a study on tabletting of Morinda citrifolia a herb known as Mengkudu in Malaysia and traditionally used for treating coughs, fever, nausea, and colic. For centuries, this herb was consumed at home by the method of infusion, and only later that the herb was marketed in the form of concentrate, tea sachet, capsules and tablets. The tablet is a universal form in the modern medicine due to its ability to provide uniform product composition, particle size and density distributions, and to eliminate dust formation; and most importantly, it has a longer shelf life compared to the other forms of delivery. It is achieved by pressing a blend of ingredients into a tablet. In this study, a 13-mm-diameter cylindrical uniaxial die was used. Pressures ranging from 7.5 to 75 MPa were applied to the powder. The effect of binder upon tabletting was also investigated using microcrystalline cellulose, with composition ranging from 10 to 60 % of the blend. The strength of the tabletted herb was then tested using an indirect tensile strength test, called diametrical compression test. The results were presented in form of pressure-volume relationship, tensile strength, and stress relaxation. The experimental data was compared to prediction using a first order model. The results indicated that this simple approach can be used to understand the tabletting behaviour of the herb.
Fracture Mechanisms of Natural Fiber Reinforced Composites at High Temperatures
Al Emran Ismail
Faculty of Mechanical & Manufacturing Engineering,
Tun Hussein Onn University of Malaysia (UTHM),
Parit Raja, Batu Pahat, 86400 Johor, Malaysia
In the last decade, natural-fiber composites of thermoplastics and thermosets have been embraced by European car makers for door panels, seat backs, headliners, package trays, dashboards, and trunk liners. Now the trend has reached North America. Natural fibers have benefited from the perception that they are green or eco-friendly. Exterior automotive parts generally exposed to temperature higher that ambient temperature. Temperature played an important role in strengthening or weakening the natural fiber reinforced composites through fiber shrinkage and result interfacial debonding of the embedded fibers. In this work, extruded composites contained different fiber loadings are stressed at different temperatures to failure. Stress versus strain curves are recorded and analyzed to study the effect of temperatures on composite strength. Scanning electron microscope (SEM) is used to observe the fracture mechanisms of the composites. The results showed that surrounding temperatures have a significant effect on composite strength and failure mechanisms.
Harmonic Balance Analysis of the Downconversion Optoelectronic Mixer in HBT Photodetector
S.M.Idrus, A.Hussain, H.Harun, A.B. Mohammad
Photonic Technology Centre,
Faculty of Electrical Engineering,
University Technology of Malaysia,
81310, Skudai, Johor Darul Takzim.
An optoelectronic mixer (OEM) performs the detection and the frequency conversion of signal between radio frequency (RF) and intermediate frequency (IF). The RF is converted to an IF to allow improved selectivity and an easier implementation of low noise and high gain amplification. OEM can be used in many applications such as in Radio over Fibre Subcarrier Multiplexed (RoF SCM) systems, where it can down-convert the microwave subcarrier frequency to lower IF in order to recover the original baseband information. In this paper, we demonstrate an OEM down-converter as the optical receiver front end configuration for SCM RoF system. A three-terminal InP/InGaAs heterojunction bipolar transistor (HBT) with optical access has been used in this OEM configuration. In this work we reported -24.75dB maximum internal mixing efficiency obtained by using the non-linear harmonic balance simulation technique.
Algorithm for Magnetic Field Visualization of a Flat Plane Induced by Finite Dipole Segment Using GCC and Gnuplot
Rashdi Shah Ahmad, Chew Teong Han
Department of Physics, Faculty of Sciences,
Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor, Malaysia
Magnetic field visualization has been playing an important role in a a wide area of application such as magnetoencephalography (MEG). In the MEG technique, measurement of magnetic field induced by the activated region of neurons in human brain is carried out.; an inverse problem approach. An activated neuron can be simplified into a current carrying finite length segment or wire. By applying the Biot-Savart Law for a finite length segment, magnetic field induced at any point can be calculated. In this reseach, the magnetic field induced by such finite length segment on a flat plane is simulated; a forward problem approach. Although the real approach used by MEG and in this research is different but there is still some significance behind. In forward problem approach, the location source is known and the magnetic field is generated. However, in inverse problem approach, the magnetic field is detected and the location of source is to be determined. By using forward approach, the magnetic mapping is obtained and by comparing the results with the MEG’s, the mapping can be re-generated by reducing the difference bewteen the measured value and calculated value. As a result, when the mapping match the calculated one, the location of source can be determined. The plane chosen is divided into grids that acts as measurement point. By using vector analysis, neccessary parameters were determined and the numerical results is represented in an iso-field plot. An algorithm is written in C programming laguage using the Gnu Compiler Collection (GCC) which provides some extra options compared to the standard C programming. For vusualization purpose, a program called Gnuplot is used. These two softwares are open source and free softwares. Such usage of them will encourage the contributions from anyone to their respective area of interest without worrying much about budget in terms of softwares manipulation.
Synthesis of Zeolite A by Ultrasound Irradiation Technique
1H. M. Razif, 1N. H. N. Hadzuin, 2 T. Sugeng and 1A. J. Aishah.
1Faculty of Chemical and Natural Resources Engineering, 2Ibnu Sina Institute for Fundamental Science Studies, Universiti Teknologi Malaysia,
81310 UTM Skudai, Johor, Malaysia
Zeolite A synthesized from colloidal silica by ultrasound irradiation technique is compared with the material obtained by hydrothermal technique. The composition is at molar ratio of 1 Al2O3: 0.85 SiO2: 3.0 Na2O: 200 H2O. X-Ray diffraction (XRD) and Scanning Electron Microscope have been used to characterize the products. Although, XRD pattern of both samples showed typical peaks of zeolite A, intensity of peaks were higher for ultrasound irradiation technique compared to the hydrothermal technique. Moreover, SEM analysis indicated the crystal size of zeolite A synthesized by ultrasound irradiation technique (1.7-5.2µm) is smaller compared to the hydrothermal technique (1.9-5.5 µm). Thus, ultrasound irradiation has a potential to be applied in synthesizing zeolite A.
Modeling of an Agent Based Schedule: Preliminary Study
Nuzulha Khilwani Ibrahim, Rozana Diana Ahmad Rusli, Nurulhuda Firdaus Mohd Azmi
Centre of Advanced and Software Engineering, Universiti Teknologi Malaysia City Campus,
Jalan Semarak, 45410 Kuala Lumpur
Agent is computer program that can do work for the user. They are responsible for doing task on the behalf of the user and also train the user and monitor event. Therefore we propose an agent based approach in scheduling reservation system which each person has an agent that negotiates with other agents to schedule the meeting. The agent should support their associated human user in complex process of meeting to be better and faster. In this paper, we also focus on benefit of agent during handling the problems occur in meeting process. Agent based scheduler system is the system uses a multi agent paradigm, where independent agent are responsible for deciding how the task is to be achieved and actually performing the necessary set of action, including handling interaction with other agent. We offer solutions using agent paradigm in this new application area, with aims to improve the optimization of scheduling to achieve greater efficiency and throughput. To this end, we described which agent is more suitable to improve the overall solution.
Preparation of Pt/Carbon Nanocomposites with Hollow Structure Using TiO2 Photocatalytic Reaction
Yun Hau Ng, Takashi Harada, Shigeru Ikeda and Michio Matsumura
Research Center for Solar Energy Chemistry, Osaka University, 1-3 Machikaneyama, Toyonaka 560-8531, Osaka, Japan.
Highly dispersed platinum nanoparticles embedded in hollow carbon layers were successfully prepared by a TiO2 photocatalytic reaction for the first time. By photoirradiating an aqueous TiO2 suspension containing hexachloroplatinic acid (H2PtCl6) and phenol, photoexcited electrons and positive holes which generated on TiO2 were consumed to reduce the Pt4+ and oxidize the phenol precursor, respectively. This induced the simultaneous photodeposition of Pt and polymerization of phenol onto TiO2 particle, which eventually resulted in Pt-loaded TiO2 fully covered by phenolic polymer. Upon carbonization of the phenolic polymer followed by removal of the TiO2 through chemical etching, hollow carbon containing Pt nanoparticles were obtained. Transmission electron microscopy (TEM), N2 adsorption-desorption analysis, Fourier transform infrared (FTIR) and thermogravimetry (TG) measurements were used to characterize the nanocomposites synthesized. The catalytic reactivity of this Pt/Carbon nanocomposite in the liquid-phase hydrogenation of various linear and cyclic olefins was compared with that of commercially available activated carbon-supported Pt catalyst.
Micellar Electrokinetic Chromatography Determination of High Explosives Residues In Post Blast Water Samples Following Solid Phase Extraction