|PHYSICAL AND MECHANICAL PROPERTIES EVALUATION OF INJECTION MOULDED 316L STAINLESS STEEL USING NEW DEVELOPED THERMOPLASTIC NATURAL RUBBER (TPNR) BINDER SYSTEM|
The present study investigates and evaluates the sintering characteristics of injection moulded gas atomised 316L stainless steel powder using new developed binder system based on thermoplastic natural rubber (TPNR). Model experiments were conducted with new wax based and palm-based biopolymer binder mixed with TPNR. The feedstock having 65 vol. % of metal powder with different formulations were injection moulded into a test bar. A rapid two stage debinding process involving solvent extraction and thermal pyrolysis was successful in removing the palm stearin binder in short time. The specimens were then sintered under vacuum atmosphere in the temperature range of 1320 C to 1380 C. The sintering studies were conducted to determine the extent of densification which corresponds to microstructural changes. In addition, the properties of the sintered specimens such as physical appearance, microstructure evolution and mechanical properties were presented and discussed. The results showed that as the sintering temperature increased, the sintered properties improved and the powders could be sintered to near-full density. The mechanical properties of the samples sintered at 1360 °C and 1380 °C complied with the MPIF Standard 35 MIM Specimens.
Author: Mohd Afian Omar and Norita Hassan
|OPTICAL BIOSENSOR READER FOR DETECTING AMMONIUM |
A portable and wireless optical biosensor reader was developed to detect and measure the ammonium concentration on site. The biosensor reader uses glutamate dehydrogenase (GLDH) and diaphorase (Dph) enzyme as biosensors that respond to the presence of ammonium upon exposure to green light at the wavelength of 565 nm. The absorption of light depends on the concentration of the ammonium compounds. The reader measures light intensity (Io & Is), performs signal processing and displays the concentration result on any android based smartphone via Bluetooth communication. With various calibration curve established for every test, a new linear model is developed. The R2 and accuracy of the device is measured and compared with that of a standard spectrophotometer. It is found that the device has better performance and accuracy. KEYWORDS: Optical biosensor reader, smartphone, ammonium, glutamate dehydrogenase, diaphorase, Internet of Everything (IoEs).
Author: Noraishah Shamsuddin, Nur Ellina Azmi, Rahimi Alrozi, Mohd Amin Said, Fakrul Rafidi Elias and Saharudin Hamzah
|OPERATIONAL CARBON FOOTPRINT OF LIGHT RAIL TRANSIT SERVICE IN THE GREATER KL/KLANG VALLEY METROPOLIS|
The transport sector is one of the major sources of greenhouse gas of many countries, including Malaysia. Rail transit service is increasingly accepted as the mode of mobility that contributes towards a low carbon economy. Malaysia introduced the light rail transit (LRT) service beginning with the Kelana Jaya Line which has become the primary means of commuting in Greater KL/Klang Valley since its operation in 1998.
Kelana Jaya Line was used as the case study to establish the carbon footprint (CFP) of the LRT service. The function of the LRT was defined as providing fully covered transportation using 2-cars or 4-cars trains for commuting passengers along the specific track line. The functional unit of the CFP is measured as per passenger per km for a product system boundary covering cradle to grave descriptions.
Based entirely on secondary data for electricity consumption, the ghg profiles for production phase and use phase of a rolling stock or car-train of 30 years life-span are 2,645 g CO2equiv and 388,601 g CO2equiv, respectively. Overall, the largest source of ghg emission for the CFP of LRT service is electricity for propulsion and ventilation of the rolling stock accounting for more than 99% of the life cycle ghg profile. TheCFP of LRT transportation based on the Kelana Jaya line was calculated as 0.091 g CO2equiv/passenger.km based on the ridership of year 2011.
Authors: Chen Sau Soon, Muhammad Zuhayr Dzul Haimi and Anuar Nordin
Keywords: Light rail transit, carbon footprint, greenhouse gas, Greater KL/ Klang Valley
|IN VITRO CYTOCOMPATIBILITY OF SYNTHETIC CALCIUM PHOSPHATE POWDER ON L929 FIBROBLAST CELL |
The effects of a synthetic biphasic calcium phosphate powder (BCP) on cytocompatibility have been investigated and compared with the commercial hydroxyapatite (HA) and tricalcium phosphate (TCP) using L929 fibroblast cells as an in vitro model. BCP was synthesized using wet synthesis technique at Ca/P ratio 1.6 and sintered in atmospheric condition to obtain both HA and TCP peaks simultaneously. The results showed that all materials BCP, HA and TCP were non-toxic and biocompatible on L929 cells. Viability study using Alamar Blue assay indicates that cells treated with all materials were more than 90 % viable at all concentration tested. Qualitatively, the observation using MEM elution shows discrete intracytoplasmic granules, no cell lysis and no reduction of cell growth. Observations of L929 cells exposed to BCP, HA and TCP showed that the cells are viable and excellently differentiate. They were proliferating and growing well from day 1 to 7 of incubation. It is demonstrated that BCP cytotoxicity condition is comparable with commercial HA and TCP. These results suggest that BCP has osteoconductive property, and could be beneficial for biomedical application due to combination of a balanced rate between more stable (HA) and more soluble (TCP) phase in body environment. KEYWORDS:calcium phosphate, cytocompatibility, non-toxic, osteoconductive
Author: . Ibrahim, M. A. Marzuke, Z. H. Hussin, N. S. Kader Bashah
|IN-VITRO BEHAVIOUR OF BIPHASIC CALCIUM PHOSPHATE WITH DIFFERENT RATIO OF SILICA CONTENT IN SIMULATED BODY FLUID|
Hydroxyapatite (HA) and tricalcium phosphate (TCP) are bioactive calcium phosphate (CaP) ceramics which function as a promising material for bone substitute due to their almost similar composition to the inorganic components of natural bone (Zhang et al., 2006). Thus, with the combination of both CaP’s features of more stable and more soluble, it is possible to formulate a biphasic calcium phosphate (BCP). Several studies reported that the combination of silica-based bioactive glasses on the CaP enhanced the structure for implant materials in the human body to repair and replace diseased or damaged bone (Ning et al., 2005). The main purpose of this study is to determine the degradation rate of BCP in different ratios of silica (Si) after immersion in simulated body fluid (SBF). The percentage of weight loss and pH value for both types of samples from 0-30 days were carried out. The study revealed that pH value increased from 0 wt.%Si to 5 wt.%Si, followed with increasing immersion time and both values remained at neutral condition (7.0-7.9). The weight loss also increased with increasing immersion time. Through the gradient of the graph, the results indicated that one cylinder disc of Si-BCP will degrade in 625 days for 0 wt.% Si, 735 days for 1 wt.% Si, 518 days for 3 wt.% Si and 705 days for 5 wt.% Si, respectively. Keywords: Hydroxyapatite, Tetracalcium phosphate, Silica, Simulated body fluid.
Author: S. Sahid, N.S. Kader Bashah, S. Sabudin
|GINGER SPECIES AND THEIR TRADITIONAL USES IN MODERN APPLICATIONS |
Ginger is traditionally known for its medicinal and culinary value. There are various species and variant of ginger in Malaysia and other tropical Asian countries, some are grown commercially, while some are still left unexplored. Scientific evidences have proven that active phytochemicals of gingers possess numerous biological and medicinal properties such as anti-tumor, antioxidant, anti-inflammatory and many others. There is a need to exploit the medicinal properties of gingers for modern application such as in medicine, supplement and cosmetics, aligned with consumer demands for safe, natural, and sustainable, effective and economical product. In order to produce high-valued product, several aspects of upstream and downstream processes of gingers should be considered such as sustainability of supply chain, standardization and quality control, efficient extraction processes, stability and proven efficacy of the extracts. Keyword: Zingiberaceae, traditional medicine, cosmetics, biological activities, extracts, phytochemicals
Author: Zanariah Ujang, Nurul Izza Nordin, Thavamanithevi Subramaniam
|A REVIEW ON SOLAR THERMAL TECHNOLOGIES FOR LOW AND MEDIUM TEMPERATURE INDUSTRIAL PROCESS HEAT |
Solar heat for industrial process has a large potential to be implemented in Malaysia especially for low and medium temperature application. This article reviews solar thermal technologies for industrial process heat in term of type of solar collector technologies for low and medium operation temperature, its potential application in selected industrial sectors and type of industrial processes. Then, it discusses the potential of this solar process heat specifically in Malaysia based on the energy demand data. It also provides information on how the solar energy can be possibly integrated into industrial process heat. Finally, the article presents four solar process heat demonstration plants that have been installed worldwide. KEYWORDS: Solar heat for industrial process, low and medium temperature, solar collectors, solar heat integration, Malaysia’s potential
Author: Nofri Yenita Dahlan, Mohd Fauzi Ismail
|A MORPHOMETRIC STUDY OF THE NORMAL HUMAN EAR IN HUSM USING COMPUTER BASED MEASUREMENT TECHNIQUE|
A study of the human auricle is important to give prior knowledge of average value for standard parameters of the ear. Prosthodontist uses this value when reconstructing the prosthetic ear in order to achieve a pleasant aesthetic glance of the patient with a problem of ear deformity. This study has successfully provided morphometric data of standard ear parameters of both the left and right ear for the Kelantan population. Morphometric study was conducted on 68 samples of normal left and right ears. 15 parameters were measured. Data was retrieved from Computed Tomography (CT) scans and converted to 3-dimensional (3D) digital images using soft tissue development. Results from this morphometric analysis provided the mean and standard deviation values for auricular length and width, length and height of tragus, insertion length of auricle, length and width of lobular and conchal, protusion at superaurale and tragal level as well as the inclination and symmetrical angle.
KEYWORDS: Ear morphometric, CT scan, 3D image
Author: Nor Azura Mohamed and Zainul Ahmad Rajion