Pusat Pengajian Sains Fizik - Tesis

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Basement Configuration And Tectonic Evolution In Abu Tumayam Trough Western Sirt Basin Using Integrated Application Of Potential Field And Seismic Data
(2025-04)
Rajab, Eshanibli Abdelhakim S
The study area is called abu tumayam trough in the western sirt basin, northeastern libya. The abu tumayam trough's basement configuration and tectonic evolution have been interpreted using potential field (gravity and magnetic) and 2d seismic data to support exploration operations. Gravity and magnetic data have been analysed using high-pass filters, total horizontal gradients, cet grid analysis, theta derivatives, source parameter imaging (spi), euler deconvolution, gm-sys inversion modelling, and werner deconvolution. This study utilised 2d seismic lines and well data to generate accurate and reliable subsurface models. The bouguer gravity and residual bouguer gravity anomaly of the abu tumayam trough show a central region have low gravity anomaly values ranging from -52 to -7 mgal and -26 to 18 mgal, respectively, while the total magnetic intensity (tmi) and reduction to the pole had the highest anomaly value of 320 nt in various regions. The reduction to the pole map (rtp) had the highest anomaly value of 405 nt in the eastern region. According to gravity and magnetic data, the total horizontal gradient, cet grid analysis, theta derivative, and euler deconvolution all show faults trending nw-se, ne-sw, nnw-sse, ene-wsw, and n-s.
Modeling The Impact Of Ammonia On The Formation Of Atmospheric Particles In Low Sulfur Environment In Beijing-Tianjin-Hebei, China
(2025-03)
Wei, Zhe
Haze pollution is a significant environmental challenge in china, with recent efforts focusing on reducing particulate matter concentrations, especially pm2.5. Reducing primary pollutants is recognized as a crucial approach to lower pm2.5 and its secondary compositions, especially now that ammonia (nh3) reduction is considered more efficient. This work applied the weather research and forecasting model with chemistry model (wrf-chem) combined with the brute force method (bfm) for sensitivity analysis to quantify the contribution of pollutant reduction to pm2.5 and its secondary compositions in january 2016, in beijing-tianjin-hebei region. The second objective of this study is to analyze the characteristics of ph pollution in handan and its influence on the formation of secondary components of pm2.5. The third objective is to refine the emission reduction strategies in the beijing-tianjin-hebei region based on how ph variations affect the formation of secondary compositions. The results showed that the 30%_so2_40%_nh3_40%_nox contributed the largest contribution (6.8%) to pm2.5, followed by 3.8% of 30%_so2_60%_nh3_60%_nox and 3.4% of 30%_so2_40%_nh3. A synergistic control measure for nh3, nox, and so2 would not only reduce pm2.5 concentrations, but also controlled the formation of secondary inorganic aerosol.
Half-Dyon Solutions In Su(2) Yang-Mills-Higgs Theory And Weinberg-Salam Model
(2025-04)
Wong, Guo Quan
Magnetic monopoles—hypothetical particles with single magnetic poles—challenge electromagnetic theories by suggesting electricity-magnetism symmetry. First integrated into quantum mechanics by Dirac and later supported by ’t Hooft and Polyakov in grand unified theories, they evolved with Cho and Maison’s electroweak monopole potentially producible in modern colliders due to its TeV-range mass. Our research expands previous work by examining half-integer topological charge for 𝑛 ≥ 1 with electric charge parameter 𝜂, introducing a new type of half-dyon carrying negative magnetic charge. We study generalized axially symmetric half-dyon solutions in SU(2) Yang-Mills-Higgs (YMH) theory with two distinct types: Type I (positive magnetic charge along negative 𝑧-axis) and Type II (negative magnetic charge along positive 𝑧-axis).
Fabrication And Characterization Of Hybrid Colloidal Silicon Carbide Quantum Dots On Nanostructured Silicon For Photovoltaic Application
(2025-02)
Olajide, Olaoye Abdulmutolib
Silicon carbide (sic) is one of the most promising semiconductor materials for optoelectronics owing to its superior properties such as high resistance to chemical, electrical and optical degradation. Semiconductor nanoparticles smaller than 10 nm have shown size-dependent physical and chemical properties. Sic nanoparticles in the size range of 1-6 nm are in the centre of interest in wide-ranging areas such as optoelectronics, photovoltaics, quantum optics, bioimaging, and medical diagnostics, owing to its enhanced luminescent properties. In photovoltaic application, the use of colloidal 3c-sic quantum dots (qds) has not been fully realized as a down-convertor, to recover the absorbed photon loss due to thermalization loss. In this work, the synthesized colloidal 3c-sic qds exhibit particle size in the quantum confinement size range and enhanced photoluminescence and absorbance with large stokes shifts of ~277 nm (4.48 ev), which is due to the decrease in particle size smaller than the exciton bohr diameter (4 nm) of bulk 3c-sic. The large stokes shift is an indicative of good down-converting material. The broadband absorption of crystalline silicon (c- si) is improved via the metal-assisted chemical etching technique which decreases the broadband reflection of the c-si. To investigate the photoconductive effect of the qds, hybrid colloidal 3c-sic/b-si with enhanced photoconductivity is synthesized for different concentrations of qds (9, 12 and 15 mg/ml).
Comparison Of Internal Dosimetry Evaluation Of Fluorine-18 Fluorodeoxyglucose (18f-Fdg) For Positron Emission Tomography (Pet) Using Olinda/Exm And Geant4 Monte Carlo Simulation
(2025-03)
Zaini, Muhammad Zulfadhli
Pet/ct with 18f-fdg is increasingly used for diagnostic imaging, making dosimetry evaluation crucial to reduce unnecessary radiation exposure to other organs. This study aimed to compare and evaluate the absorbed dose to patients undergoing 18f-fdg sequential pet/ct imaging in the ikn using olinda/exm and geant4 mc simulation, focusing on identifying the most suitable method for clinical application and analysing whether the absorbed dose comply with the safety standard set by icrp 128. The study involved retrospective analysis on 30 adult patients. Inclusive of 13 men and 17 women with mean age, weight and administered activity were 55.10 ± 14.05 years, 68.87 ± 20.99 kg and 327.61 ± 87.95 mbq respectively. Olinda/exm version 1.1 and geant4 mc simulation (version 10.6.0) software were used to evaluate the absorbed doses to liver, kidney and urinary bladder. Mird5 mathematical phantom were used in geant4 mc simulations whereas in olinda/exm, adults male and female models which the organ mass were normalized with japanese reference model were applied.

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