Pusat Pengajian Sains Fizik - Tesis

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Sifat-Sifat Optik Filem Nipis Germanium Amorfus Tersejat
(1993-03)
Saw Kim Guan
Filem nipis germanium amorfus dimendapkan pada kaca borosilikat melalui penyejatan vakum. Kesan ketebalan filem ke atas jurang optik, Eg, filem a-Ge yang dimendapkan pada suhu bilik dengan kadar cepat dan lambat dikaji dan dibandingkan.
SNESS - An Expert System Shell
(1994-05)
Singh, Pratul
Looking at the prevailing trend, an attempt has been made in this thesis to develop a shell on PC, using C++ language. C++ language is an extension of C language and it retains the efficiency of C and is compatible with existing C programs. In the present work we have emphasized on the core of an expert system shell which consists of a facility to input knowledge and create a knowledge base and an inference engine that operates on the knowledge base to develop the desired system.
Mass Energy Absorption Coefficients Of Selected Biologically Equivalent Materials
(2001-09)
Shakhreet, Bassam Zuhdiothman
One of the most important gamma radiation quantities in respect of radiation dosimetry and health physics applications concerns is mass energy absorption. Direct measurements of the coefficient of mass-energy absorption, μen/ρ, are difficult and typically recourse is taken to theoretical computations. In this study we have determined μen/ρ using a simple and direct method based on paraxial sphere transmission using a proportional response gamma detector. The effects of nonparaxiality and of finite sample thickness have been accounted for, using extrapolation procedures. The deviation from nonproportionality and other corrections have been shown to be small.
Attenuation And Scattering Studies Of Natural And Fabricated Particleboard Of Rhizophora Spp.in The 15.77 - 25.27 Key Photon Energy Range
(2006-10)
Shakhreet, Bassam Zuhdi Othman
Mass attenuation coefficients of Rhizophora spp. were determined in the photon energy range of 15.77 - 25.27 keV using a method based on X-ray fluorescence (XRF) with a system setup in L-shape geometry and utilizing a SiPIN detector. The performance of each individual component in the setup was tested separately and its characteristics recorded for optimal use. The XRF system was then examined as an integrated assembly. To provide electron density information in support of the introduction of new tissue equivalent materials for mammography phantoms, the electron density of Rhizophora spp. wood was also measured and determined. The measured value (3.183 ± 0.003) x 1023 e/cm3 at photon energies 15.77, 17.48 and 22.16 keV is reasonably close to the calculated value of (3.195 x 1023 e/cm3 ). Furthermore, the accuracy of the values is good. In general, the electron density of water (3.341 x 1023 e/cm3 ) and the electron density of values for breast tissues ranging from (3.120 - 3.510) x 1023 e/cm3 (ICRU, 1992) are comparable to the measured Rhizophora spp. values. The linear and the mass attenuation coefficients of natural Rhizophora spp. phantom from three different parts of one tree (top, middle, and bottom) were determined in the photon energy range of 15.77 to 25.27 keV.
Fabrication And Characterization Of Normoxic Polymer Gel Dosimeter By Using Raman Spectroscopy At Low X-Ray Energies
(2012-12)
Aifa Aflrah Binti Rozlan
Polymer gel dosimeters are fabricated from radiation sensitive chemicals which, upon irradiation, polymerize as a function of the absorbed radiation dose. Two types of normoxic polymer gel dosimeters were fabricated, which is PHEAG (polyhydroxyethyl acrylate) and PHEMAG (polyhydroxyethyl methacrylate) gel dosimeters. These polymer were fabricated by using gelatin, N' N-methylene-bisacrylamide (BIS), ascorbic acid (AA), deionized water and 2-hydroxyethyl acrylate (HEA) for PHEAG and 2-hydroxyethyl methacrylate for PHEMAG. The ability of AA to bind oxygen in the gel solution was investigated by using an oxygen dissolve meter. The concentrations of AA used are 5, 10, 15 and 35 mM and each concentration was applied to each batch of PHEAG and PHEMAG. The sensitivity of PHEAG and PHEMAG towards low X-ray energy was investigated. The structural changes of the monomeric components in PHEAG and PHEMAG after irradiation were analyzed using Raman spectroscopy.
Slow Pyrolysis Of Palm Wastes And Properties Of Biochar Blended Coal Briquettes
(2014-01)
Inuwa, Ibrahim Abdullahi
The disposal of large amount of agricultural residues in developing countries causes a detrimental effect to the environment. Thus, this study is aimed at converting oil palm wastes from oil palm mill, into briquettes to significantly reduce the consequences following the existing disposal system. In this study, pyrolysis experiments were conducted from 300°C to 700 °C with heating rate between 5°C/min to 30°C/min by a lab-scale pyrolysis system. The results obtained showed, the quantity and quality of products mostly depend on the pyrolysis parameters (temperature and heating rate). The calorific value and carbon content of PKS biochar were 28.27 MJ/kg and 72.42%, which is significantly greater than that of coal sample of 26.21 MJ/kg and 64.66%. While moisture and ash content in biochar is 1.02 mfwt% and 4.88 mfwt which is lower than that of coal with 7.40 mfwt% and 6.62 mfwt% respectively. The composite PKS biochar and pure coal (bituminous) are mixed with percentage compositions of 100:0,80:20, 70:30, 60:40, 50:50, 60:40, 70:30 and O: 100 respectively. A different proportion of2, 2.5, 3, 3.5 and 4% cassava starch for the total mass of the mixture were used as the binder. The different compressed pressure of 80, 90,100, 110 and 120 kg/cm2 at 2 dwell times was used. Among the briquettes samples tested p 100 contained lowest moisture of 2.56 mfwt% and ash of 5.36 mfwt% with highest fixed carbon of 54.49 wt %. The increase in pure coal into the blend has led to a reduction in the energy value of the briquette from 29.83 to 25.55 MJkg-l. Cassava used as binder portrayed an insignificant effect in the calorific values of the briquettes. In the water boiling test analysis showed, pure biochar briquette PIOO generates the highest temperature up to 920.67°C compared to biochar-coal mixture briquettes and pure coal sample.
Enhancement In Resistivity Resolution Based On Data Amalgamation Technique
(2015-12)
Bery, Andy Anderson
The 2-d electrical resistivity imaging measured resistivity distribution at the subsurface. Improvement in 2-d resistivity data quality was carried out by the data levels amalgamation (dla) technique which is based on overlapping data levels with two different arrays combination. The first study objective is to develop the numerical comparative assessment for individual array and the dla technique of two different arrays. The second objective is to improve resolution using the dla technique on two different arrays. The final objective is to validate the dla technique of two different arrays. In order to achieve all three objectives, the study was carried out in three different phases. The first phase involved 2-d computerized models or namely synthetic models and a field model are presented. Five different synthetic models are created and used to investigate the imaging capabilities using four different arrays. In second phase, the numerical comparative assessment is introduced for the individual array and the dla technique. The two best and suitable arrays were determined based on the numerical comparative analysis results. In phase three, validation of the dla technique using two best and suitable arrays are applied to the actual field surveys. Based on the numerical comparative assessment for both 2-d computerized models and a field model, it shows that the dla technique of pole-dipole (p-d) and wenner- schlumberger (w-s) arrays are able to provide good data quality of image.
Fabrication And Characterization Of Tio2 - Pvp Nanofibre Using Electrospinning Method For Hydrogen Gas Sensing
(2016-08)
Abed, Nabeel Zabar
In this project, anatase phase titanium dioxide (TiO2) nanofibers (NFs) are successfully fabricated using the homemade electrospinning (ES) method. This study aims to fabricate uniform and high quality anatase TiO2/polyvinylpyrrolidone (PVP) NFs on the glass substrate. A number of parameters were studied for the development of best form of nanofibers; the most suitable/optimised parameters for the fabrication of hydrogen gas sensor device were found at room temperature. Xray diffraction (XRD) patterns show sharp and well-defined peaks identified as anatase phase. Field emission scanning electron microscope (FESEM) images revealing the formation of nanofibers are investigated. Surface topography observations by atom force microscopy (AFM) indicate that the roughness is improved by effect of the parameters selected and optical properties were measured using ultraviolet-visible-near infrared (UV-Vis-NIR.) spectrometer.
Reduction Of Backscattered Radiation For X-Ray Image Quality Enhancement
(2016-12)
Qaed Naji, Abdullah Taher
This study mainly aims to reduce backscattered radiation inside an X-ray room. The characteristics of X-ray attenuation in several materials such as lead, copper, iron steel, aluminium, and concrete have been investigated under different exposure parameters to measure their abilities to attenuate incident X-ray and to reduce backscattered X-ray. Lead and Iron presented good attenuation values for incident X-ray at radiographic diagnosis energy range (50 -110 kVp), whereas iron and aluminium reflected the least amount of backscattered radiation dose. A number of anti-scatter grids have been designed and fabricated from iron steel and aluminium, because of their relatively better abilities to reduce backscattered radiation compared to other materials.
Growth Of Zno Nanorods On Wire Via Sonochemistry Method For Glucose Sensing
(2017-02)
Rayathulhan, Ruzaina
There has been much research on growth of ZnO nanorods on vanous substrates, and various growth methods. Sonochemical method is a well-known method for growing nanorods. Metal wire is a suitable substrate for the growth of ZnO nanorods as it can then be used as sensor electrode for sensing application. However there has not been any report on growth of ZnO nanorods on metal wire directly using sonochemical method. ZnO nanorods were directly grown on four different wires (silver (Ag), nickel (Ni), copper (Cu), and tungsten (W)) through sonochemical method and the best sample was chosen as electrode and tested for glucose sensing. Zinc nitrate hexahydrate and hexamethylenetetramine (HMT) were used as precursors for the growth of ZnO nanorods. The optimum condition for the growth of ZnO nanorods were determined by varying precursor molarity, sonication time and molar ratio of precursor solution.
Delineation Of Seulimeum Fault System And Identification Of Geothermal Signatures Using Ground Magnetic And 2-D Resistivity Imaging Methods
(2017-02)
February 2017
Ground magnetic and 2-D resistivity imaging method are widely used in geophysical exploration for subsurface identification to study the earth rheology such as fault process based on the geophysical parameter. Ground magnetic and 2-D resistivity imaging surveys were conducted to investigate the trend of Seulimeum fault system and the signature of potential geothermal surface manifestation resulting from the fault. Four different sites, namely Krueng Raya, Iejue, Lamtamot, and Tangse were chosen as study area for Seulimeum fault study while two sites; lejue and Ie-Seu 'Urn were chosen as case study areas in identifying the geothermal signatures. Ground magnetic method was performed using proton magnetometer while the 2-D resistivity imaging survey was done using ABEM Terrameter with Pole-dipole array. The magnetic residual contour map in Krueng Raya locality shows the dislocation from northwest to southeast (NW-SE) direction with contrast of high and low magnetic residual ranging from -150 nT to 300 nT which interpreted as the geological fault. In Iejue site the result shows the contrast of magnetic residual between -150 nT to 300 nT which indicate as geological fault continuous from Krueng Raya.
The Biostimulation Of Low Level Laser Irradiation On Blood Parameters: Ex Vivo
(2017-07)
Al Musawi, Mustafa Salih Ali
Various low-level laser wavelengths have been used for a variety of clinical applications because of their ability to modulate blood rheology and improve microcirculation. The response of human blood to low-level laser irradiation (LLLI) provides important information about the interactions of laser light with living tissues. This study was designed to investigate whether in vitro LLLI changes the erythrocyte sedimentation rate (ESR) and other blood indices of whole blood. Blood samples were collected by venipuncture into ethylenediaminetetraacetic acid (EDTA)-containing tubes. Each sample was divided into two equal aliquots as a control (non-irradiated) and irradiated samples. The irradiated sample was subjected to LLLI doses of 36, 54, 72 and 90 J/cm2 at wavelengths of 405, 589 and 780 nm.
Enhanced Led Thermal Conductivity Of Filled Epoxy Resin Containing Multimodal Distribution Of Ceramic Particles And Graphene Sheets
(2018-07)
Permal, Anithambigai
Present work was designed to investigate the class of possible materials to be compounded as thermally conductive composite as well as to be catered as thermal interface material (TIM) for an improved thermal performance of a high power light emitting diode (LED) headlamp, a product of OSRAM Opto Semiconductors. This research was earned out to produce a closely packed ceramic and graphene filled hybrid epoxy composite. The work was earned out by understanding the physical and chemical behaviour of aluminium nitride (AIN), boron nitride (BN) and aluminium oxide (AI2O3). Also a comparison of compatibility between two commercial epoxy matrices has been presented in this work. The thermal conductivity of unimodal AIN, bimodal A1N/BN and bimodal AI2O3 were investigated.
Random Laser Action In Zinc Oxide Nanorodspreparedbychemicalbath Deposition
(2018-09)
Alias, Nor Fazrina
Recently photon localization effects that give rise to random lasing in ZnO have been widely studied. However the fabrication method required complicated and high cost system. Thus an alternative method is necessary to consider. This study aimed to fabricate ZnO nanorods using low cost yet robust via chemical bath deposition. In this work, ZnO nanostructures were grown onto ZnO seeded glass substrates with different ZnO seeding thickness.
Simulation And Performance Studies Of Thermally Efficient Light Emitting Diodes Drivers
(2018-09)
Mohd Supian, Norazlina
The thermal behaviour of an electronic package is often characterized by evaluating the junction temperature and thermal resistance at the junction of a single or multiple heat source to ambient. In the case of IC LED drivers, the heat source within the device is either single or multiple due to presence of many integrated component such as transistor, internal resistor, etc on a single die. Hence the evaluation of IC drivers with single or multiple heat sources is absolutely necessary for imparting suitable thermal management within the device. In this study, thermal transient measurement method and computational fluid dynamics (CFD) simulations have been used to measure thermal resistance and junction temperature.
The Development Of Light Emitting Diode (Led)-Based As A Baby-Friendly Device For Treatment Of Neonatal Jaundice
(2018-09)
Zainudin, Nadira Syuhada
Sixty percent of newborns are jaundiced in their first two weeks oflife for their liver is immature and unable to cope with the production of bilirubin. Phototherapy treatment is proven and widely known to treat hyperbilirubinemia. The common light sources used in conventional phototherapy device are special blue fluorescent tubes, compact fluorescent tubes (CFT), halogen spotlights and fibre optic blankets. However, the conventional device is capacious, expensive and cost involved in periodical maintenance. Hence, the idea ofBiliBaju which based on LED is to develop a low cost, mobile, and baby-fiiendly phototherapy device, and promising the same or better effectiveness in treating neonatal jaundiced.
Detection Of Subsurface Geological Features Using Selected Geophysical Techniques
(2018-10)
Arisona
This study aimed (i) to simulate synthetic model using selected geophysical techniques buried subsurface, (ii) to characterize the subsurface geological features based on field data and (iii) to validate the measured physical parameter using statistical analysis.
Optically Pumped Lasing Properties Of ZnO Nanorods
(2018-11)
Nordin, Muhammad Nuri
The purpose of this study is to investigate the characteristics of optically pumped laser from the ZnO nanorods grown by using the two-step chemical bath deposition (CBD). Samples are grown on two types of substrates, glass and sapphire wafer, AI2O3. Various conditions and treatments of the samples have been introduced to observe the optical emission mainly by manipulating the thickness of ZnO seed layer thin film and the heat treatment condition. The procedures for CBD process is fixed for four hours at 97“C for growth process with the solutions of 0.05 M of zinc nitrate (Zn(NO.3)2.6H2O) and 0.05 M of hexamethylenetetramine (11 MT).
Assessment Of Uranium, Lead, Cadmium And Iron In Maternal And Umbilical Cord Blood Samples In Iraq
(2019-03)
Hasan Rhaif Al-Sahlanee, Mayyadah
The assay of blood samples is a preferred method for monitoring the internal exposure of radiological and toxicological contaminants in human body. The objectives of this study were to evaluate the status of uranium (U) radioactivity and selected heavy metals such as lead (Pb), cadmium (Cd) and iron (Fe) in maternal and umbilical cord blood samples for normal and deformed infants in Iraq, and the influence of these elements to the foetus development and to identify predictors of maternal exposure. Additionally, to assess the interactions between these elements in the maternal and umbilical cord blood samples. A cross-sectional study was conducted in three public hospitals (Al-Yarmouk Teaching Hospital, Al-Basrah Maternity and Children Hospital and Al-Shatra Maternity Hospital).
The Growth Of GaN-Based Low Dimensional Structures By CVD Using Platinum And Palladium Catalysts
(2019-03)
Tan, Lay Kim
This research project presents the growth of low dimensional GaN structures employing monometallic catalyst (Pt and Pd) and bimetallic catalysts (Pd/Pt) by means of chemical vapor deposition based on vapor-liquid-solid mechanism.

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