Z.A. Talib, S.F. Khor, E.Z.M. Tarmizi, H.A.A. Sidek, W.D.W. Yusoff,
W.M.M Yunus and A.H. Shaari
Department of Physics, Faculty of Science,
Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
Binary calcium phosphate and ternary calcium phosphate containing ZnO glasses have been synthesized by melt quenching technique over a wide composition range. The electrical properties of theses glasses were investigated by ac impedance spectroscopy from 10 mHz to 1 MHz for temperatures ranging from room temperature to 300 oC. In this work, ternary glasses with mole fraction = 0.01 to =0.09 with interval of 0.02 and binary glasses with mole fraction = 0.05 to =0.4 with interval of 0.05 were investigated. The conductivity of both samples show dispersive behavior at lower temperatures while at higher temperatures the conductivity is almost constant at the lower end of the frequency, approaching the dc conductivity limit and rises rapidly as the frequency is increased. We also noted that as the frequency is increased, the conductivity shows a dispersion which shifted to higher frequencies with the increase in temperature. The dc conductivity () was found to increase with higher temperatures. The impedance plots show only one semicircle indicating the presence of one type of conduction mechanism. Activation energy, and for were found to be slightly higher than. Bulk resistivity () decreases with increase in temperature for the both materials. However, bulk resistivity for is higher than . Increasing ZnO concentration will increase value of when compared with the . The values decrease as temperature is increased irrespective of ZnO doping.
Multistate Survival Analysis on the Presence of Diabetes Related Complications
Yuhaniz Hj Ahmad, M. Ataharul Islam and Noorani Ahmad
School of Mathematical Sciences, Universiti Sains Malaysia
This paper illustrates the use of multistate approach to product limit method developed by Islam (1994) under the competing risk framework for diabetes related complications among diabetic patient. The method takes into account of the censored and uncensored survivorship functions separately. To identify the risk factor for the diabetic related complications, an exponential regression model under the competing risk framework were used. Since more than one complication could occur, thus, only the incidences of the first complication among the diabetic patient were considered in the study. The complications are cardiovascular, peripheral vascular, cerebrovascular, ophthalmic, neurologic and renal disease complication.
The Quality Analysis Of Polycrystalline Diamond Coated Si3N4 Using Raman Spectra: The Effect Of Chamber Pressure And Microwave Power
A.Purniawan1, E. Hamzah.1, M. R. M. Toff2.
1 Department of Materials Engineering, Faculty of Mechanical Engineering,
Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor Malaysia
2 Advanced Materials Research Center (AMREC), Lot 34, Jalan Hi-Tech 2/3,
Kulim Hi-Tech Park, 09000 Kulim, Kedah, Malaysia.
Diamond (sp3) is the hardest material and high chemical resistant that is one form of carbon structure. Another structure namely graphite (sp2), diamond-like carbon (DLC), disordered sp3, and other sp2 that are hopeless the presence on the surface, however non-diamond structure caused decreasing of diamond properties to identification sp3 or sp2 structure. Raman spectroscopy is a standard tool for the characterization of carbon materials. In the work, the effects of deposition parameters namely chamber pressure and microwave power was studied. Furthermore, the characterization of diamond coating quality was carried out by using Raman spectra and its microstructure was investigated by Field Emission Scanning Electron Microscopy (FESEM) in order to study the effect of deposition parameters on diamond quality. Based on the SEM images, the chamber pressure has more significant effect on nucleation and faceting of diamond. Microwave power also affected the facet that changes cauliflower to octahedral structure. Furthermore Raman spectra analysis found that the quality of polycrystalline diamond increase with increase both parameters.
Ice Point Blackbody Cavity for Checking the Performance of an Infrared Radiation Thermometer Operating Near 0 °C
Irene Safinaz Hassan , Hafidzah Othman , Md. Nor Md. Chik
National Metrology Laboratory,
SIRIM Berhad (NML-SIRIM), 43900 Sepang, Selangor
The usage of infrared radiation thermometers has expanded tremendously in Malaysia. Their distinct capability of measuring an object’s temperature without contact has boost up its popularity among industries. For an infrared radiation thermometer that operates near 0 °C, the simplest method to check if it is working reliably is by using ice point check. The ice point check should be performed at regular basis and the ice point reading is normally taken as the first impression of the thermometer’s performance. An ice point blackbody cavity has been designed and constructed at NML-SIRIM, Malaysia. It is a mean to measure the ice point reading of client’s infrared radiation thermometer that operates near 0 °C. The ice point check will predict the performance of the thermometer at other temperature range.
Measurement and Calibration of Frost Point and Dew Point Meter
Faridah Hussain, Hafidzah Othman, Md Nor Md Chik
National Metrology Laboratory,
SIRIM Berhad (NML-SIRIM), 43900 Sepang, Selangor
Dew point sensors are commonly used in various type of industry to detect the presense of small amount of water vapour. Industries involved are compressed air, breating air for medical, plastic processing, natural gas and many others. In certain application such as in medical, dew point of compressed air used for breathing purposes shall be continously monitored in order to prevent it exceeds 4 °Cdp. In order to support these industries, National Metrology Laboratory, SIRIM Berhad has a Two temperature/two pressure frost point generator for range -95 °C to 10 °C used to supply a test gas for calibrating and validating a wide range of dew point sensors. This paper describes the measurement technique during the measurement and calibration. The capabilities provide traceability for Malaysian industries, research organizations and other accredited laboratories.
Identification and Characterization of a Marine Pseudoalteromonas Sp from
Wan Siti Nur Atirah Wan Mohd Azemin1, Mohd Shahir Shamsir Omar1, Azmi Rani2
1Biology Department, Faculty of Science
Universiti Teknologi Malaysia, Johor, Malaysia
2Brackishwater Aquaculture Research Centre,
Department of Fisheries, 81550 Gelang Patah, Johor Bahru,Johor.
Marine bacteria have been shown to have symbiosis with fish by living on its skin or mucus. The aim of this study is to isolate potential symbiotic bacteria from farmed marine fish. Mucus samples were collected from skin of farmed fish Bawal Emas (Trachinotus blochii) in order to identify and characterize potential symbiotic marine bacterium. The fish was isolated from Sungai Johor estuary at Kong Kong, Johor. The sample was investigated by use of a phenotypic approach and a phylogenetic approach based on genes encoding 16S rRNA. The strain was gram negative rods, motile, aerobic and grows at optimal temperature 37°C. On the basis of several phenotypic characters and a phylogenetic analysis of the genes coding for the 16S rRNA, this strain was identified as a possible Pseudoalteromonas sp. Species of Pseudoalteromonas are generally found in association with marine eukaryotes and display anti-bacterial,bacteriolytic, agarolytic and algicidal activities. The production of a range of compounds such as antimicrobial peptides which are active against a variety of target organisms appears to be a unique characteristic for this genus and may be of potential use in the future.
Biolistic-Transformation of Impatiens Balsamina Using Hph Gene for Hygromycin Resistant
Aishah Mohd Taha, Alina Wagiran, Zaidah Rahmat and Fahrul Zaman Huyop
Department of Biology, Faculty of Science,
Universiti Teknologi Malaysia, Skudai ,Johor, Malaysia.
Cotyledon explants of Impatiens balsamina were bombarded with plasmid pRQ6 contained hph gene encoding hygromycin phosphotransferase for hygromycin resistance and uidA gene encoding for GUS as reporter gene. Both genes were driven by cauliflower mosaic virus (CaMV) 35S promoter. Condition for optimal delivery of DNA to explants was developed based on transient GUS assay within 24 h post-bombardment. Cotyledon explants were cultured on osmoticum solution- containing medium (0.2 M mannitol and 0.2 M sorbitol) 16 h before bombardment. The bombardment was carried out at 28 Hg vacuum pressure, a helium pressure of 1100 psi, 9 cm of target distance, the plasmid DNA of 1.0 µg with one time bombardment. Only 14 of the plants in 75 mg/L hygromycin were GUS positive. PCR analysis to detect hph gene resulted on 18.3% transformation frequency.
Preparation and Conductivity Studies on Poly(Methyl Metacrylate)-Epoxidised Natural Rubber Blend Solid Electrolytes
Madzlan Aziz1 nd Famiza Abdul Latif2
1Jabatan Kimia, Fakulti Sains, Universiti Teknologi Malaysia and 2Jabatan Kimia, Fakulti Sains Gunaan, Universiti Teknologi Mara
Employment of solid electrolytes in power sources such as lithium batteries is a challenge. In order to function well as an electrolyte it has to meet certain criteria. One of the important criteria is a good ionic conductivity. Poly(methyl metacrylate) (PMMA) has the potential as it has a reasonably good conductivity value in the order of 10-9 Scm-1. Although it has the conductivity needed but it is brittle and as such couldn’t provide the interfacial properties to perform as an electrolyte. In order to increase interfacial contact it has to be more flexible that it can withstand pressure. To introduce flexibility PMMA is blended with rubber. The type of rubber used is 50% epoxidised natural rubber (ENR50). The PMMA-ENR blends were prepared with suitable compositions so as to produce free standing films. Free standing films were obtained when PMMA was blended with 10 and 20% ENR50. A series of percentage by weight PMMA-ENR50 blends were prepared by solvent casting. The films cast have a thickness in the order of 0.1 mm. The ionic conductivities were evaluated using the impedance values obtained using an impedance analyzer. The highest conductivity value obtained was 6.63 x 10-10 Scm-1. In the presence of lithium salts as used in lithium batteries the conductivity values increased by three order of magnitude or more to 5.05 x 10-7 Scm-1 for LiNO3 salts and 5.09 x 10-5 Scm-1 for LiCF3SO3. Temperature dependence studies were also conducted to elucidate the mechanism of conduction and the Arrhenius behaviour suggests ionic conduction similar to ionic solids.
Theoretical and Empirical Comparison of Coupling Coefficient and Refractive Index Estimation for Coupled Waveguide Fiber
Saktioto, Jalil Ali, Jasman Zainal, Rosly Abdul Rahman, Bashir Ahmed Tahir
Advance Optics and Photonics Technology Center (AOPTC), Physics Department
Science Faculty, Universiti Teknologi Malaysia (UTM)
81310 Skudai, Johor Bahru, Malaysia
Power transmission of coupling ratio for coupled waveguide fiber depends on coupling coefficient. The coupling coefficient obtained in experimental result as a function of separation of fiber axis and refractive index of core and cladding varies in a wide range. For empirical formula, coupling coefficient can be calculated from experimental result of coupling ratio distribution 1-75%. Theoretically, it has a dependence of some parameters resulting sinusoidal curve. Both empirical and theoretical formulae are compared to obtain new phenomena of refractive index of fibers after fusion.
Characterization of Low Pump Power Nd:YAG Laser
Abd Rahman Tamuri, Wan Rashidah Wan Majid, Noriah Bidin & Yaacob Mat Daud.
Laser Technology Laboratory,
Physics Department, Faculty of Science,
Universiti Teknologi Malaysia,
81310 Skudai, Johor Bharu
Nd:YAG laser is the most commonly used type of solid-state laser in many fields at present because of its good thermal and mechanical properties and easy maintenance. However the range of output energy of lasers available in the market is limited. This is also allow very narrow scope of application either in scientific research or medical used. Hence the aim of this project is to design and construct Nd:YAG laser with specifically having wide range of energy. This is accomplished by designing special power supply to power flashlamp. The flashlamp was used to pump Nd:YAG laser rod. The flashlamp and the laser rod were placed parallelly (for seek of grade pumping) in a ceramic heat sink chamber. To avoid the temperature gradient due to the heat from pumping process, cooling system was provided. A plano-concave resonator was set up to amplify the beam and generate laser output. Capacitor voltage was verified with in 0 to 900 V to get wide range of energy. Infrared sensor card, powermeter and burn paper were employed to detect the laser output. The maximum output this designed laser is 250 mJ.
Epitaxial Method of Quantum Devices Growth