Pusat Pengajian Sains Fizik - Tesis

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Green Synthesis Of Gold Nanoparticles As Photosensitizer For Phototherapy Breast Cancer Treatment
(2024-07)
Al-Mafarjy, Sarah Shakir Mutar
Breast cancer is a significant cause of mortality among women, and current treatments like chemotherapy and radiotherapy can lead to severe long-term side effects. Therefore, alternative strategies are necessary. This study investigated the combined use of low-level laser therapy (LLLT) and gold nanoparticles (AuNPs) to enhance hyperthermia effects selectively in breast cancer cells. AuNPs were synthesized through a simple cost-effective method using aqueous plant extract, aiming to reduce toxicity and agglomeration issues. A novel green synthesis method utilizing Coleus scutellarioides (L.) Benth leaves was developed, and comprehensive characterization was performed. The cytotoxicity of synthesized AuNPs was evaluated using the MTT assay on human breast cancer (MDA-MB-231) and human foreskin fibroblast (Hs-27) cell lines, revealing a dose-dependent reduction in cancer cell viability within 24 hours. Subsequently, this study investigated the impact of low-level near infrared (NIR) 808 nm laser irradiation on both cell lines, with and without AuNPs. Various parameters were explored, and the presence of AuNPs significantly enhanced the effectiveness of NIR laser irradiation in inhibiting MDA-MB-231 cell growth, suggesting a promising treatment avenue. Notably, exposure of Hs-27 cells to a 300 mW laser for the double duration (10 and 15 minutes) led to less than 50% cell viability compared to the effects of other output laser powers and times used.
Polynomial Model Of Transmission And Reflection Of Electromagnetic Waves In Multilayer Thin Films Subjected To An External Transverse Voltage
(2024-07)
Elhabbash, Mohammed K. M.
In designing and controlling the transmission and reflection characteristics of multilayer thin films, mathematical modelling of their electrical and optical response is a vital step to save time, effort and money in the experimental fabrication process. Different approaches exist for modelling the propagation of electromagnetic waves through multilayer thin films. This thesis employs the polynomial approach to model the electromagnetic wave, utilizing dielectric constants, electrical resistivities, and refractive indices of thin film materials to infer the transmission and reflection of electromagnetic wave incidents on the multilayer structure when one or more accumulated-charge regions superimpose between adjacent layers. The model, based on Maxwell's equations was derived for nonmagnetic lossless or lossy materials. Wave Tensor and Wave Tensor-II, home-grown MATLAB codes, were used to simulate the polynomial model for three pairs of materials: pair consists of a non-magnetic lossy material, germanium, and a non-magnetic lossless material, magnesium oxide. Second pair are two non-magnetic lossless materials, magnesium oxide and calcium fluoride. Third pair of materials are two non-magnetic lossless materials: calcium fluoride and silicon dioxide. The dielectric constants, electrical resistivities, and refractive indices of chosen materials were outsourced from trustworthy references.
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.
Development Of New Self-potential Acquisition Technique For Ground Subsurface Investigation
(2024-08)
Jinmin, Mark
Self-potential (SP) method is a passive geoelectrical method. It measured the natural potential differences which exist between any two points on the ground. The points are measured using an electrode known as the roving electrode and the base electrode. In the SP method, these electrodes are often called ‘porous pots’ which are designed not to create any chemical potential once they are contacted on the ground. A reference electrode is used as a base electrode, and the second electrode is used to measure the potential on the ground. The primary research is to introduce the practical techniques in SP data acquisition which is Self-Potential Enhancement Technique (SPET). SPET is a combination of techniques which are the electrode calibration technique (EC), the optimum electrode time technique (OET), and the closed loop. Using a pair of electrodes consumes more time and energy during data acquisition. Hence, the EC is to calibrate and correct the electrode error during data measurement, which is able to use multiple electrodes. An inconsistent time period for mitigating an electrode on the ground can lead to inaccurate self-potential data readings. Thus, the OET purpose is to identify the time frame for an electrode to be in equilibrium on the ground. The SP has an electrode configuration for acquiring the electrical potential data such as gradient and fixed base. The gradient technique has some disadvantages in the data quality, such as cumulative error, electrode polarization, drift effect, time-varying potential, soil contact effect, and reading errors.
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.

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