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Current state and future prospect of solar energy in an electronic device manufacturing company / Vickneswary Vadivelu
No full textSolar energy system is a potential energy recruitment which helps to reduce greenhouse gases to the environment. The implementation of solar energy in industrial sector assist to achieve the nation’s renewable energy goals. The aim of this research is to analyse the efficiency of photovoltaic system installed at a selected industrial area and its future prospect in terms of economical, social acceptance, and environmental benefits. The research site is located at the city of Shah Alam, Malaysia. The objectives of the research are to determine the total energy generated, analyse cost saving and CO2 reduction from the solar panel installed at the electronic devices manufacturing site. In addition, the acceptance and perspective of renewable energy among the employees were assessed in smaller scale. Furthermore, the challenges in execution and its future prospect were also identified. The methods used in the research work are study case analysis and data collection techniques such as group focus discussion, questionnaire, and utilizing archived data. The research determined the current total energy reduction of year 2019 and 2020 from the installed solar system versus conventional energy usage in 2018. The roadmap of future solar energy installation from year 2022 to 2027 at selected site determined at 19% of CO2 reduction. As conclusion, the study reveals research limitations and suggestions to improve the growth of solar energy at manufacturing site
Interrogation of structural variations of pro-oncogenic AGR2 protein in supporting esophageal cancer progression / Nurul Hanani Baderol Hisham
No full textA non-hormone-dependent cancer, esophageal adenocarcinoma was classified as the sixth
deadliest cancer with an elevated mortality rate resulting from failure detection at an onset
of the disease hence causing the tumor to be at either an advanced or metastatic stage
upon diagnosis. Such cancer progression initially reported to be due to many factors
including the emergence of pro-oncogenic protein such as the AGR2 protein, known to
play roles mainly in the folding of proteins as well as maintaining proteostasis in the ER.
The poor understanding on the structural functions of the AGR2 protein in supporting
esophageal cancer progression has led to the design of this research which involved
constructing four AGR2 protein variants comprised of the AGR2 – WT variant as to
compare the basal expression to the other mutated variants, the AGR – KDEL variant to
enhance localization of the protein in the ER, the mAGR2 – ΔKTEL variant to enhance
secretion of the protein into the extracellular environment and the ΔNterm AGR2 – KDEL
variant to enhance the dimerization of the protein. All constructs of AGR2 protein which
were AGR – WT, AGR2 – KDEL, mAGR2 – ΔKTEL and ΔNterm AGR2 – KDEL were
cloned into the pSF-CMV vector before basal expression of the AGR2 protein variants
were determined by transiently transfecting them into the FLO-1 esophageal
adenocarcinoma cell line and conduction of immunoblotting and immunofluorescence.
The intracellular expressions of the FLO-1 showed the highest expression observed by
the AGR2 – WT variant followed by AGR – KDEL. Such expressions were further
validated by immunofluorescence. Reduced extracellular expressions of the AGR2
variants in FLO-1 were observed only in two variants, the AGR2 – WT and the AGR –
KDEL, while no extracellular expression was observed for the mAGR2 – ΔKTEL variant. The expressions of the ΔNterm AGR2 – KDEL variant either intracellularly or
extracellularly could not be validated either by Western blot or immunofluorescence due
to the lack of transfection efficiency. The accession on the influence of the AGR2 protein
variants towards proliferation and migration of the FLO-1 observed from wound healing
assay revealed significant elevations for FLO-1 proliferation and migration in AGR2 –
WT, AGR2 – KDEL and mAGR2 – ΔKTEL (p<0.05). The viability of the FLO-1
transfected to AGR2 – WT, AGR2 – KDEL and mAGR2 – ΔKTEL through conduction
of MTT assay revealed a significant result (p<0.05) supported by an increase in the
absorbances of the cells with respect to time in contrary to Alamar Blue assay conducted
which revealed an insignificant result (p>0.05) suggesting that the transfected AGR2
protein variants were independent towards the viability of the FLO-1
Cucumber green mottle mosaic virus as a Nanoparticle: Biodistribution, immunostimulation and expression / Lee Wei Wei
No full textViral nanoparticles (VNPs) derived from plant viruses have many advantages due to their bio-compatibility and bio-degradability in vivo, ability to self-assemble in 3 dimensions and capacity for large scale production. Compared to the animal VNPs, plant VNPs are likely to be less or non-pathogenic to human. Cucumber Green Mottle Mosaic Virus (CGMMV) is a single stranded, positive sense RNA virus from the family of Tobamovirus that has the potential to be developed as a nanoparticle for vaccine and adjuvant applications. In this study, CGMMV nanoparticles were found to be produced more efficiently in its native host Cucumis melo var Earl favorite compared to the other alternative local varieties. In vivo study of subcutaneously injected CGMMV nanoparticles in a mouse model demonstrated that it is distributed in a wide range of tissues without causing any toxicity and inflammation. It is also able to induce high level of antibody production without the need of adjuvants. Infectivity of CGMMV nanoparticles extracted from the mouse tissues however is greatly reduced. Moreover, CGMMV nanoparticles can act as immunostimulator in vitro by stimulating the innate immune response and confer protection against Vesicular stomatitis virus (VSV) and Sendai virus (SeV) infection in RAW246.7 cells. Lastly, chimeric CGMMV vectors were engineered to express selected M1 influenza epitopes at the 3’ terminal of coat protein. The epitopes can be co-expressed at the surface of the viral coat protein during replication in plants. However, no significant difference in immune response was observed between the chimeric and wild-type CGMMV nanoparticles upon testing in mice. Taken together, the results suggest that CGMMV nanoparticle is a potential vaccine carrier and adjuvant candidate. Further study is needed to tease out the underlying factor required for CGMMV chimeric nanoparticles to induce immune response against influenza epitopes
Feasibility of peanut residual cake extract as the coagulant for water turbidity removal / Sara Elsaied Ahmed Ali
No full textIn this study, the potential use of the peanut residual cake extract (PRCE) as the coagulant for water turbidity removal during water treatment has been investigated. PRCE was prepared by grinding it to powder using the ordinary household blender. PRCE was extracted using a solution made of 3 molar of sodium chloride (NaCl) to extract the active ingredient. The feasibility of PRCE coagulant was investigated using kaolin synthetic turbid and further tested with river water via the jar test. The study included the variables of coagulant extraction time and types of mixing during coagulation and flocculation; which were rapid and slow mixing with different initial level and concentration of pH and turbidity values. Rapid mixing time ranged from 1 to 4 minutes, while slow mixing time varied between 15 to 30 minutes. Finally, the performance of PRCE was compared with aluminum sulfate (alum) for the variable of extraction time, found that the most efficient coagulant extraction time occurred after ten minutes onward (n = 7, Anova Test at p = 0.05). Meanwhile, for the operational mixing time variables of rapid and slow, the latter has given a better result. Simple optimization study also included both variables of initial pH and turbidity values. It was found that pH from 6 to 8 was found to be effective in removing 96-98% of the turbidity. Under optimum conditions with the PRCE dosages from 5 to 10 mg/l), it was that had able to remove more than 90% of turbidity for the initial concentration of 200 to 500 NTU. Validation of PRCE as an effective coagulant was done by comparing it with alum; Both had shown that their results were comparable for turbidity removal efficiency, which were found to be at 90 % and 95.2 %, respectively
Designing a scaffolding peer learning tool for the online component of blended learning / Rasheed Abubakar Rasheed
No full textBlended learning involves the combination of face-to-face with online component instructions and is considered the most effective and most popular mode of instruction adopted by today’s educational institutions due to its perceived effectiveness in providing flexible, timely and continuous learning. However, the inclusion of technology into instruction thereby creating the online component has brought some level of unease to students, teachers and educational institutions. Several studies have reported the various problems that students, teachers and educational institutions face with the online component of blended learning. The leading challenge associated with the online component of blended learning is students’ inability to proper self-regulate their learning activities due to the numerous types of challenges associated with online studying. Research on scaffolding students’ self-regulation in the online component of blended learning has not proposed a unified scaffolding solution to enable students to overcome these various challenges as well as engaging them in proper self-regulation in their online components. Several studies have proclaimed peer learning as a learning strategy that is capable of alleviating online component challenges thereby enabling students to fully realize the benefits of blended learning instruction. As such, a deductive methodological approach was adopted which involves investigating and carefully understanding the practices and key elements of peer learning from various research domains in order to understand how to engage students to a peer-learning self-regulation strategy for scaffolding their online component of blended learning. The first stage involves designing online peer learning groups based on learning potential and affinity models, leveraging the design of learning system features to instigate group dynamic elements for facilitating and motivating small group peer learning, and fostering pro-social behaviors by offering indirect incentives for combating the inherent problems of reluctance to students’ peer-learning participation. Then, a learning system prototype is implemented to ascertain the identified peer learning key features and elements to enable the applicability of the peer learning scaffolding approach in real-life scenarios. An experiment involving 120 undergraduate university students using the widely adopted experimental and control group evaluation method shows significant improvement in students’ learning achievements by using the proposed peer learning scaffolding approach. The main contribution of this research is a peer learning framework for educational institutions to adopt as a tool in order to revise their blended learning instruction for scaffolding their student’s online component studying
Knowledge, attitudes and practices of smoking among university students in Thailand: A quantitative study / Busaban Chirtkiatsakul
No full textSmoking remains a public health concern in several countries, especially among young adults. The aim of this study is to: 1) determine the prevalence of smoking among university students in Thailand and identify associated factors, 2) examine the general level of knowledge, attitudes and practices with regards to smoking and identify associated factors, and 3) investigate whether attitude domains mediate the relationship between knowledge domains and practice domains. A cross-sectional study was conducted among 1,299 students from five public universities in Thailand using a selfadministered questionnaire. Factor analysis, multiple logistic regression, multiple linear regression, the causal-step approach, and 95% confidence interval bootstrap percentiles were used for analysis. Results showed that 28.2% of students were smokers. 75.3% of students had a high knowledge, 49.5% had equivocal attitude and 79.0% had poor practice. Factors significantly associated with smoking were male, aged 21 years and
above, enrolled in a non-science major, living off campus, having a family member or friend who smoked, having a favorable attitude toward smoking, and having an equivocal attitude about smoking. Gender, age group, and field of study were important factors influencing knowledge about smoking. Being a male was associated with less anti-smoking attitudes, less positive preventive practices, more positive perceptions about smoking, and more negative practices. Having a family member who smoked was associated with more positive perceptions about smoking; however, having a family member who smoked was associated with higher positive preventive practices. Having a friend who smoked was associated with more positive perceptions about smoking and more negative practices toward smoking. Based on the mediation analysis, anti-smoking attitude mediates the relationship between the domains of knowledge and positive preventive practice, and also mediates the relationship between the domains of knowledge and negative practice. Positive perceptions about smoking act as a mediator between all knowledge domains and negative practices. Understanding the influencing factors of smoking, knowledge, attitudes, and practices toward smoking, and the connection among them provides helpful insights for tobacco control policies in universities
Fluid-structure interaction modelling in type B aortic dissection: Effect of intimal flap and aortic wall motion on hemodynamics / Chong Mei Yan
No full textAortic dissection is a life-threatening vascular disease that is initiated by the development of a tear in the intima aortic wall layer, allowing high pressure blood to enter the aortic wall and separate the wall layers, forming a true lumen (TL) and a false lumen (FL), which are separated by the intimal flap. During the acute phase of type B aortic dissection (TBAD), the first two weeks since symptom onset, uncomplicated patient is preferentially treated medically, and thus naturally transitions into the chronic state. However, patient follow-ups continue to show a high number of late complications mainly caused by incomplete FL thrombosis, despite best medical treatments. While computational fluid dynamics (CFD) is a promising modelling technique to assist the clinical management of TBAD by providing insight into the complex hemodynamics of TBAD, most CFD studies reported so far are based on rigid wall simulations, assuming wall motion has a minor effect on the hemodynamics. Hence, this thesis aims to develop and validate a monolithic, fully coupled fluid-structure interaction (FSI) computational framework to account for realistic flap motion in TBAD. To achieve this aim, an idealised phantom geometry, relevant to anatomical measurements of acute dissected human aorta was constructed. Large flap motion of up to 4.6 mm is examined, and the influence of flap motion on flow has been quantitatively analysed in terms of TL and FL flow splits, disturbed flow in the FL, luminal pressure difference, wave propagation and time-averaged WSS indices. Next, the developed FSI model was combined with a shear-driven thrombosis model described by a series of convection-diffusion reaction equations. The integrated FSI-thrombosis model aimed to investigate the interaction between vessel wall motion and growing thrombus, which has not been reported elsewhere in TBAD. Further extension of the FSI approach was performed on patient-specific cases to validate computational results with 4D flow MRI and Doppler-wire pressure measurements. In comparison with CFD model, the substantial movement of flap mostly increases the flow resistance in the TL and causes more disturbed flow in the FL. The flap-induced luminal pressure is dampened, thereby affecting pressure measures. Regarding FL thrombosis, the wall compliance and flap motion sped up the progression of thrombus growth and formation. The continuous development of vortices caused by drastic flap motion, induced high shear stress and shear rates around tears. This helped to transport activated platelets further to the neighbouring region, thus accelerating thrombus formation in the FSI models. In the end, the FSI results have been validated and good agreement between FSI models and in-vivo data was observed. The high jet velocity entering the primary entry tear was captured accurately by the FSI models, while the average pressures predicted by the FSI models matched closely with the Doppler-wire readings. The incorporation of drastic aortic wall motion as reported in the TBAD patients can be reproduced in the patient-specific FSI models. The movement of the aortic wall and flap influenced the TL/FL flow splits, pulse pressure and pressure difference between the TL and the FL
A mechanistic study of the neurite stimulative and cyto-protective properties of sclerotial extracts of Lignosus rhinocerotis Ryvarden / Tan Yong Hui
No full textNeuritin, a member of the neurotrophic factor family, is important in neuritogenesis, neurite arborization, and neurite extension. Although the neurite stimulatory effect of Lignosus rhinocerotis sclerotia extracts are well-documented in literature, the role of neuritin and its correlation to neurite outgrowth and cyto-protection in L. rhinocerotis treated pheochromocytoma (PC12) cells remained unknown. Therefore, this study aims to investigate the involvement of neuritin protein in L. rhinocerotis-induced neurite outgrowth and cyto-protection against hydrogen peroxide-induced oxidative stress. Freeze-dried L. rhinocerotis sclerotia powder was subjected to aqueous and ethanolic extraction. Pheochromocytoma cells were cultured in low serum and treated with nerve growth factor (5 ng/ml) and extracts (20-1280 μg/ml) for 48 hr. Cytotoxicity of the extracts was assessed and the average length of neurites from 20-30 cells was calculated based on 5 microscopic fields at 200x total magnification by measuring their axon-like extensions with each extension defined as double the length of cell body diameter. Neuritin concentration was quantified using an enzyme-linked immunosorbent assay. Ribonucleic acid (RNA) extraction was carried out to investigate differential expression of genes involved in neurogenesis via PCR array profiling and real-time PCR. The viability of PC12 cells upon hydrogen peroxide-induced oxidative stress in pre- and co-treatment with extracts was determined before selecting the best neuroprotection model to proceed with oxidative stress, mitochondrial membrane potential, and mitogen-activated protein kinase phosphorylation quantification using flow cytometry. GCMS analysis was carried out to identify the compounds that are present in the ethanolic extract. The IC50 values obtained from the tetrazolium (MTT) assay showed no toxic effects following 24 hours of exposure of PC12 cells to the extracts. There was a significant difference (p ≤ 0.05) in neuritin protein abundance in 640 μg/ml aqueous-treated (5.00 ± 0.83 ng/ml) and 50ng/ml NGF-treated PC12 cells (5.00 ± 0.96 ng/ml) as compared to untreated cells (1.86 ± 0.65 ng/ml) with average neurite length of 98 ± 12 μm, 106 ± 13 μm, and 73 ± 9 μm, respectively. Neuritin protein abundance is directly proportional to the average neurite length in PC12 cells treated with L. rhinocerotis aqueous extracts. Seventeen genes out of 84 genes in the PCR array were commonly expressed in positive and extract-treated cells as compared to untreated cells. These genes were found to involve cell differentiation, synaptic transmission, as growth factors and cytokines during neurogenesis. In terms of cyto-protection, pre-treatment and co-treatment for 24 hours with aqueous extract recorded viability of more than 80%. No significant difference in neuritin concentration in the cyto-protection experiment. It was also interesting to note that cyto-protection properties of extract were not via reactive oxygen species reduction but through prevention of mitochondrial membrane depolarization. Based on ApoTox-Glo triplex assay, treatment of PC12 cells with extracts mitigates cells by reducing apoptosis events. Fatty acids, phenol, phytosterol, and dicarboxylic acid were found in L. rhinocerotis ethanolic extract. In conclusion, the mechanistic action of neurite outgrowth in PC12 cells upon L. rhinocerotis treatment could be facilitated by an upregulation in neuritin protein. L. rhinocerotis extracts protect PC12 cells from hydrogen peroxide-induced oxidative stress via the reduction of mitochondria depolarized cells and reduction in caspase 3/7 activity but no via regulation of neuritin expression
Quantitative and qualitative assessment of petroleum products by spectroscopic and chemical data analytics / Abd Rahim Othman
No full textThis research study describes the use of Fourier Transform Near Infra-Red (FT-NIR) technology with various chemometric methods in petroleum products. Current practice in the refinery’s quality assurance and quality control laboratories relies on the use of conventional method measurements in the quantitative and qualitative assessment of their petroleum products. These conventional methods consume high workforce, longer analysis time and high operating expenditure. A new innovative way of qualitative and quantitative measurement and application were explored to improve and address the pain points and provide a total solution. This study aims to evaluate and assess the quality of petroleum products through spectroscopic and chemical data analytics, both qualitative and quantitative assessments. In this work, coupled near infra-red spectroscopy and chemometrics techniques for calibration models development, i.e. Partial Least Square (PLS) and Principal Component Regression (PCR) and Near Infra-red (NIR) spectra pre-treatment or re-processing, i.e. Multiplicative Scatter Correction (MSC) and Savitzky Golay Second Derivative (SGSD) were employed accordingly for rapid and simultaneous determination of chemical and physical properties of petroleum hydrocarbons. The coupled NIR and chemometrics methods are an alternative to the existing laboratory reference methods to address the refinery pain points. FT-NIR spectroscopy has been successfully utilized to rapidly identify and discriminate three types of petroleum products (gasoline, diesel, and kerosene) using Principal Component Analysis (PCA). More than 95% of each product was accurately identified and differentiated. This qualitative multivariate measurement is important when fast results are required at the operation site, such as during product transfer cross-contamination and adulteration or illegal product blending. In addition, qualitative measurement by PCA was used to differentiate gasoline and diesel fuels directly sourced from refineries without additive. In contrast, additives were added to the gasoline and diesel fuels, such as corrosion inhibitors, detergency, and lubricity improvers, to enhance the engine's performance and protection of the engine components. Diesel with and without palm methyl ester (PME) blend were also determined qualitatively using PCA based on significant the presence of fatty acid methyl ester (FAME) in diesel. This work demonstrates the multivariate calibration strategy for the simultaneous near-infrared spectrometric determination of the physical and chemical properties of the petroleum products, namely the boiling point at 95% recovery (T95%), flash point (FP), cloud point (CP) and cetane index (CI) which include the spectral region selection, calibration/validation set partition, data pre-processing, and regression. Based on the results, the calibration constructed on the combination region of 4800-4000 cm-1 using the randomly selected calibration set managed to deliver excellent predictive performance in terms of coefficient of determination, root mean square error of cross-validation, root mean square error of prediction and the ratio of performance deviation. Moreover, all the developed models satisfied the reproducibility requirement of respective American Society for Testing and Materials (ASTM) standard methods regardless of the employment of multiplicative scattering correction/Savitzky-Golay second-derivatization and principal component regression/partial least square regression. This revealed that the fitness of the model relies upon every single calibration component. It was also realized that data pre-treatment is crucial in delivering predictive-performing predictions
Electrochemical removal of mercury from aqueous solution using task-specific ionic liquid immobilised on palm shell activated carbon / Hawaiah Imam Maarof
No full textElectrode design is one of the most important criteria in providing a satisfactory performance of an electrochemical process. The conventional two-dimensional (2D) electrode provides low current efficiency despite high percentage removal and recovery of metal ions from dilute concentrations. Meanwhile, emerging advanced materials, such as task-specific ionic liquids (TSIL), have presented prominently to electrode modifications' technological advancement. In this present work, two types of threedimensional (3D) electrodes were developed. The precursor is an activated carbon derived from solid waste, namely palm shell. The performance of palm shell activated carbon (PSAC) and trioctylmethylammonium thiosalicylate immobilised on PSAC (PSAC-TOMATS) electrodes were evaluated. The prepared electrodes were electrochemically characterized by voltammetric techniques and potentio electrochemical impedance spectroscopy (PEIS). Next, the prepared electrodes were employed as the cathode in a batch-mode electrochemical process system to remove Hg from synthetic wastewater. In the preparation steps and electrochemical characterization of the PSAC electrode, 20% carbon black (CB) was found to give low electron charge resistance and the maximum current peak for the redox reaction of ferrocyanide/ferricyanide. Meanwhile, by increasing the amount of binder from 10% to 20%, the electrochemical active surface area was decreased by 42%. The most suitable supporting electrolyte for the electro characterisation of the prepared electrode was NaCl because it provides the lowest double-layer capacitance effect compared to HCl and NaOH. Cyclic voltammetry data suggest that the PSAC electrode is undergoing a quasi-reversible process for which the equivalent effect, both that of the electron transfer rate and mass transfer rate, has been taking place. The presence of interfacial interaction, such as adsorption, was also observed from the chronocoulometry analysis. The removal of Hg in a batch-mode electrochemical system was very rapid using the PSAC-TOMATS electrode. However, the modified electrode required an adequate amount of TOMATS to grant a higher percentage of Hg removal. By immobilising 0.2 g TOMATS on the PSAC, a removal of 97.1% of Hg (from an initial Hg concentration of 100 ppm) was achieved within 1.5 hours of electrochemical treatment time, while the PSAC electrode required a longer treatment time (6 hours). Additionally, the PSAC-TOMATS electrode provides higher current efficiency, higher percentage removal and lower energy consumption than the PSAC electrode. Under the electrode reusability studies, the PSAC-TOMATS electrode's efficiency was found to undergo a 15% reduction after the second cycle. However, only a slight reduction (2%) was observed for the third cycle. In conclusion, an electrochemical process using the PSAC-TOMATS electrode offers a promising approach to facilitate an effective removal of Hg from an aqueous solution