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Comparative study of nanoparticles and alcoholic fuel additives with optimized synthesis of palm-sesame biodiesel using tribological and internal combustion engine testing / Muhammad Mujtaba Abbas
No full textThe demand for renewable energy is steadily increasing due to the rise in population, economic development, and environmental issue globally. Renewable energy sources are now considered better replacements for fossil fuels. Meanwhile, up to 20% of liquid fuels such as methyl esters are currently being blended with petroleum fuels. Recently, the commercialization of biodiesel is a significant challenge due to its poor cold flow properties and oxidative stability. Poor cold flow properties and oxidative stability can be improved by selecting suitable vegetable oils for producing different blends. Among all available vegetable oils, sesame seed oil (SSO) has unique cold flow properties and oxidation stability. This research aimed to improve the cold flow, lubricity, and diesel engine characteristics of biodiesel produced from the palm-sesame oil blends. Response Surface Methodology (RSM) and Extreme Learning Machine (ELM) techniques were used to develop the production process, and the input variables (time, catalyst amount, methanol to oil ratio, and duty cycle) were optimized. The optimum yield of P50S50 (50% palm + 50% sesame) biodiesel obtained was 96.61 % under operating parameters such as time (38.96 min), duty cycle (59.52 %), methanol to oil ratio (60 V/V %), and catalyst amount (0.70 wt.%). The cold flow characteristics of P50S50 biodiesel were significantly improved, such as cloud point (7.89 ℃), pour point (3.80 ℃), and cold filter plugging point (− 1.77 ℃) with better oxidation stability of 6.89 h. During the test run, the friction coefficient was measured directly using the high-frequency reciprocating rig (HFRR). The results exhibited that B10 (Malaysian commercial diesel) demonstrated a poor coefficient of friction and wear scar diameter compared with other tested fuels. The addition of ethanol as a fuel additive in the B30 fuel sample reduced fuel lubricity and increased the wear and friction coefficient compared with other fuel additives. B30 fuel with titanium oxide (TiO2) nanoparticles exhibited improved results with the minimum wear scar diameter and lowest friction coefficient among all other fuel samples. Dilution of engine oil with unburned fuels changes its lubricity and tribological properties. Lubricating oil diluted with B10 showed a high coefficient of friction (COF) with severe abrasive and adhesive wear compared with mineral lubricant, among other fuels. Lubricant+B30+TiO2 showed the minimum increase in COF value among all other modified fuels compared to SAE-40 mineral lubricant. Engine performance and emissions characteristics were studied using a compression ignition (CI) diesel engine with variable engine rpm at full load conditions. The results were compared with B30 and B10 fuels. The main findings indicated that the B30+TiO2 ternary blend showed an overall decrease in brake-specific fuel consumption compared with other tested fuels. B30+DMC produced higher brake thermal efficiency, among other fuels. B30+DMC ternary blend showed a reduction in carbon monoxide (CO) and hydrocarbons (HC) emissions compared to B30. B30+CNT ternary blend showed a slight decrease in nitrogen oxide (NOx) emissions compared to B30. The research suggests that Palm-Sesame biodiesel with fuel additives is a suitable replacement for diesel fuel in compression ignition engines without engine modification
Short pulse generations in 1.0 and 1.5 micron regions WITH AuNP and MXene TI3C2TX saturable Absorbers / Ahmad Haziq Aiman Rosol
No full textQ-switched and mode-locked fiber lasers have gained the attention of researchers due to their extensive applications in various fields including telecommunication, material processing, remote sensing and medical. These lasers are normally realized by using a saturable absorber (SA), which functions to initiate pulses by passive means. Up to date, many works have been devoted to developing new SA devices which have good optical stability and can produce high performance pulse lasers. This thesis aimed to explore the use of gold nanoparticles (AuNPs) and MXene Ti3C2Tx as SA device for Q-switched and mode-locked pulse generations in both Erbium-doped fiber laser (EDFL) and Neodymium-doped fiber laser (NDFL) cavities. Using the two materials, four SAs are prepared by employing two different techniques: liquid and film. The AuNPs were synthesized using gold (III) chloride trihydrate (50% Au basis) (HAuCl4), tri–sodium citrate (Na3C6H5O7, TSC), poly(sodium 4-styrenesulfonate) (PSSS), and sodium borohydrate (NaBH4) while the MXene Ti3C2Tx was prepared from MAX Ti3AlC2 based on selective etching technique. It is found that AuNP liquid and film exhibit the modulation depth of 5.6% and 13.6 %, respectively while MXene Ti3C2Tx liquid- and film-based SAs have modulation depth in a range of 4 - 6 %. Q-switched and mode-locked pulses have been successfully demonstrated using the newly developed AuNPs SA devices. For instance, an AuNPs liquid based SA was successfully used in the EDFL cavity to generate Q-switched pulses operating at 1563 nm with the maximum repetition rate of 107 kHz, a minimum pulse width of 1.38 μs and the maximum pulse energy of 100 nJ. The generation of mode-locked pulses operating at 1563 nm was also realized in an extended EDFL cavity based on the plasmonic effect induced by AuNPs film. The laser operated at 1563 nm with a pulse width of 2.85 ps, repetition rate of 0.99 MHz and maximum peak power of 9 kW. Q-switched and mode-locked pulses trains were also demonstrated using two types of newly developed MXene Ti3C2Tx based SAs. For instance, a soliton pulse train operating at 1562.5 nm was produced with a fundamental repetition rate of 1.89 MHz and pulse duration of 3.68 ps using the MXene Ti3C2Txfilm as SA. The mode-locked laser generated average output power of 24.42 mW, pulse energy of 12.92 nJ and peak power of 3.5kW at 144 mW pump power. The result indicates that both AuNPs and MXene Ti3C32Tx have a good nonlinearity and thus are suitable for use in various photonic devices operating in both 1.0 and 1.5 μm regions
Novel applications of organic fluorophores: White light emission, chemosensor and ambient microdroplet synthesis / Norfatirah Muhamad Sarih
Get PDFThis thesis has focused on the applications of organic fluorophore for producing white light emission, developing a fluorescence-based sensor of Fe3+ and a new method for the accelerated synthesis of dansyl aniline (DA). The first work in this research relates to a novel means to generate white light emission (WLE) by mixing three fluorescent organic compounds; furocoumarin (FC), DA, and 7-hydroxycoumarin-3-carboxylic acid (CC). This novel mixture is immobilised in silica aerogel and applied as a coating to a UV LED to demonstrate its applicability as a low-cost, organic coating for WLE via simultaneous emission. Kept in an ethanol solution while immobilised in silica aerogel, the mixture exhibits a Commission Internationale d’Eclairage (CIE) chromaticity index of (0.27,0.33). It was observed that a broadband and simultaneous emission involving CC, FC and DA played a vital role in obtaining a CIE index close to that of pure white light. The next application uses coumarin derivatives to develop a novel chemosensor for the sensitive and selective detection of Fe3+. Furocoumarin (furo[3,2-c]coumarin) derivatives have been synthesised from a single step, high yielding (82-92%) chemistry involving a 4- hydroxycoumarin [4+1] cycloaddition reaction. They were characterised by FTIR, 1HNMR, and, for the first time, a comprehensive UV-Vis and fluorescence spectroscopy study was carried out to determine if such compounds can serve as useful sensors. Based on the fluorescence data, the most promising furocoumarin derivative (2- (cyclohexylamino)-3-phenyl-4H-furo[3,2-c]chromen-4-one, FH), exhibits strong fluorescence (Фf = 0.48) with long fluorescence lifetime (5.6 ns) and large Stokes’ shift, suggesting FH could be used as a novel fluorescent chemosensor. FH exhibits a highly selective, sensitive, and instant turn-off fluorescence response to Fe3+ over other metal ions which is attributed to a charge transfer mechanism. Selectivity is demonstrated against 13 other competing metal ions (Na+, K+, Mg2+, Ca2+, Mn2+, Fe2+, Al3+, Ni2+, Cu2+,Zn2+, Co2+, Pb2+ and Ru3+) and aqueous compatibility is demonstrated in a 10% MeOHH2O solution. This novel sensor has a limit of detection of 1.93 μM, below that of the US environmental protection agency guidelines (5.37 μM), with a linear dynamic range of~28 (~2−30 μM) and an R2 value of 0.9975. As an exemplar application, the potential of this sensor was demonstrated for the rapid measurement of Fe3+ in mineral and tap water samples, establishing the real-world application of FH as a “turn off” fluorescence sensor. Lastly, the research is expended to discover the nucleophilic substitution reactions of dansyl aniline by reactive paper spray ionisation-mass spectrometry (PSI-MS). PSI-MS is an emerging tool for ambient reaction monitoring via micro droplet reaction acceleration. PSI was used to accelerate and monitor the time course of the reaction of dansyl chloride with aniline, in acetonitrile, to produce dansyl aniline. Three distinct PSI arrangements were explored in this study to represent three types of sample loading and interactions, the conventional single tip as well as two novel setups, dual tip, and a coaxial setup. The effect on product yield was investigated using these different types of paper tips for a range of geometric considerations, including distance of microdroplet travel. It was observed that product yield is increased at a given distance and decreases thereafter for all PSI configurations. Amongst the variety of sample loading methods, the novel dual tip arrangement showed increased product yield which also exhibited the
largest microdroplet density. In general, the reaction monitoring by PSI-MS with a dual tip configuration shows much promise and was further utilised for the successful synthesis of a silyl-alkylated dansyl aniline compound demonstrating a rapid and simple optimisation procedure based on ratio concentration adjustments
Finite difference method on randomly generated non-uniform meshes for poisson equation / Sanaullah Mastoi
No full textIn this research, a novel method based on randomly generated grids is proposed. This method enables fast convergence and improves the accuracy of the solution for a given problem. It also enhances the quality of precision by minimizing the error. The finite-difference method involving uniform grids is commonly used to solve the partial differential equation. However, it requires a higher number of iterations to reach convergence.
In addition, there is still no definite principle for the discretization of the model to generate the mesh. The newly proposed method employed randomly generated grids for mesh generation. This method is compared with the uniform grids method to check the validity and potential in minimizing the computational time and error. The comparative study is conducted for the first time by generating meshes of different sizes and boundary values.
The numerical solutions of partial differential equations and the generalized classification of fractional differential equations are obtained through various approaches, such as exact solutions, analytically, fractional differentiations, and the more generalized form of finite difference method over uniform novel method randomly generated grids. The proposed method is also known as sanaullah mastoi’s method or SM’s method.
The new approach is the numerical solution through the finite difference method using randomly generated grids. This study proves that the finite difference method over randomly generated grids found faster convergence iteratively, reduced computational time than uniform grids, and minimize error. A significant reduction in computational time is also noticed. Thus, this method is recommended to be used in solving the partial differential equation. However, SM’s Method’s performance may be increased by reshaping the mesh parameters, and broad scope of research is available
High-performance room-temperature ammonia gas sensor based on molybdenum trioxide nanostructure / Chua Wen Hong
No full textIn this research, h-MoO3 nanostructure were grown on tapered region of optical fiber glass via simple chemical bath deposition (CBD) to form a unique sensing element to detect ammonia (NH3) gas in room temperature. As NH3 gas sensor have been highly demanded due to its commonly utilization of NH3 gas in various industrial sectors and a highly toxic and corrosive agent that can cause threat human health and environment. Experiment parameter such as type of precursor used, precursor concentration, deposition time and annealing treatment was performed to fine-tuned the growth of h-MoO3 nanostructure and optimised the NH3 gas sensing performance. The structural, thermal and optical properties of the sample were studied by using field emission scanning electron microscope (FESEM), energy dispersive X-ray (EDS), selected area electron diffraction (SAED), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR) and UV-Vis spectroscopy. The morphology of the deposited h-MoO3 is highly affected by the types of precursors used. As different precursor concentration and deposition time also affect the overall sensing performance. Overall, the annealing treatment improves the sensitivity, respond time and recovery time of the sensor towards NH3 gas. However, overheating the sample cause disruption towards gas adsorption due to its metastable characteristic. Among them, the sodium-based h-MoO3 nanorod sample annealed at 150oC shows a stable room-temperature respond of 0.05, 0.18, 0.22, 0.28 and 0.35 au, a fast respond time of 210 s towards 500 ppm of NH3 and good stability and repeatability. The optical NH3 gas sensing behaviour have a significant relationship with the interaction between the h-MoO3 nanostructure and the evanescent wave. The chemisorbed oxygen species and physisorbed NH3 alter the refractive index and its absorption coefficient on the MoO3 nanostructure which provide manipulation of optical signal as sensing mechanism. This work proved that a chemical bath deposition grown h-MoO3 nanostructure exhibits a promising optical sensing characteristic which shed a light for new emerging gas sensing technology
Pembangunan modul strategi struktur dekonstruktivisme kata kerja tatabahasa Bahasa Tamil / Rathidevi Shanmugam
No full textTujuan utama kajian ini adalah membangunkan modul strategi struktur dekonstruktivisme tatabahasa kata kerja Bahasa Tamil untuk pelajar-pelajar sekolah menengah atas. Kajian ini menggunakan model ADDIE yang merangkumi lima fasa iaitu fasa analisis keperluan, reka bentuk, pembangunan, implementasi dan penilaian. Fasa 1: Analisis Keperluan melibatkan soal selidik terhadap 308 orang pelajar tingkatan empat yang mengambil subjek elektif bahasa Tamil dari lapan buah sekolah dan temu bual separa berstruktur yang melibatkan lapan orang guru bahasa Tamil yang mengajar bahasa Tamil Tingkatan Empat.
Fasa 2: Reka bentuk dan fasa 3: Pembangunan telah dijalankan melalui Teknik Fuzzy Delphi dua pusingan, dengan 10 orang panel pakar pedagogi dan tatabahasa dari Universiti Tempatan, Institut Pendidikan Perguruan, dan Sekolah Jenis Kebangsaan Tamil dengan menggunakan instrumen temu bual separa berstruktur untuk pusingan pertama dan soal selidik bagi pusingan kedua. Ia bertujuan untuk mengumpul maklumat mengenai pedagogi, isi kandungan, dan bahan bantu mengajar yang perlu dimasukkan ke dalam Modul Tatabahasa Kata Kerja Bahasa Tamil. Bagi fasa 4: Implementasi, modul yang telah dibangunkan diimplementasikan oleh penyelidik ke atas 70 orang pelajar Tingkatan Empat dari dua buah Sekolah Menengah Kebangsaan. Sampel bertujuan ini melibatkan pelajar tingkatan empat yang mempunyai pencapaian sederhana atau baik dalam subjek bahasa Tamil.
Fasa 5: Penilaian yang meliputi penilaian formatif dan sumatif. Tiga orang guru cemerlang bahasa Tamil sekolah menengah telah menilai modul tatabahasa bagi fasa penilaian formatif. Penyelidik telah menjalankan temu bual separa berstruktur terhadap panel penilai guru cemerlang. Matlamat utama temu bual separa berstruktur ini adalah untuk mengumpul data yang berkaitan dengan kekuatan dan kekurangan modul. Pandangan dan cadangan panel penilai guru cemerlang digunakan untuk penambahbaikan modul yang dibangunkan sebelum diimplementasikan di sekolah.
Objektif utama penilaian sumatif adalah untuk menilai kepenggunaan modul berdasarkan retrospeksi responden. Praujian mengandungi soalan berstruktur dan objektif sebelum modul diimplementasikan. Pascaujian soalan berstruktur dan objektif selepas modul diimplementasikan kepada responden. Kekuatan, kelemahan dan masalah yang dihadapi semasa menggunakan modul serta cadangan bagi penambahbaikan modul tatabahasa kata kerja telah dianalisis.
Dapatan kajian menunjukkan bahawa modul strategi struktur dekonstruktivisme kata kerja tatabahasa bahasa Tamil yang menggunakan strategi dekonstruktivisme telah berjaya dibangunkan. Modul kata kerja tatabahasa yang dibangunkan ini telah mempermudahkan pembelajaran kata kerja tatabahasa tingkatan empat di samping menarik minat, mendorong pembelajaran yang menarik dan meningkatkan penguasaan pelajar dalam kata kerja tatabahasa bahasa Tamil. Justeru itu, kemahiran mendengar, bertutur, membaca dan menulis telah dipraktikkan dalam modul ini. Penyelidik menyarankan agar guru-guru dan pelajar-pelajar dapat menjadikan modul ini sebagai bahan bantu mengajar dan sumber rujukan dalam proses pengajaran dan pembelajaran kata kerja tatabahasa bahasa Tamil
Comparative assessment on household e-Waste management in three cities in Malaysia / Mahmuda Aziz
No full textElectronic waste or E-waste is a relatively new waste stream that is fast growing because of the increased production of electronic items with short lifespans. Like other developing countries, Malaysia is also facing problems of managing E-waste. Although research have been carried out on industrial E-waste, however, E-waste from households has not been adequately studied. Thus, this study is intended to assess the current E-waste management and recycling practice among the public in three major cities in Malaysia, namely Putrajaya, Shah Alam, and Petaling Jaya. A questionnaire survey was the main method used to collect data from 1200 respondents from the three cities. From the Material Flow Analysis (MFA) 23,033 kg per year (at a rate of 19.19 kg per capita) of E-waste was generated from the study areas, from which only 15.89% was recycled. The public in Putrajaya generated the lowest amount of E-waste (17.99 kg per capita) compared to that in Petaling Jaya and Shah Alam. 33% of public generally kept their E-waste at home or sell to scrap dealers rather than sending it to recycling centers. 88.96% of electronic items was recorded as stocks (153.73 kg per capita) and air conditioner was the largest stock at 59,235 kg (28.38%). Pearson correlation revealed a significant but positively weak correlation (r = 0.067, p < 0.05) and a significant regression equation was found as well [F (1,1198) = 5.416, p < 0.05), with an R2 of 0.005 between knowledge and practice on E-waste management and recycling among the public in the three cities. From One-way ANOVA and Bonferroni Post Hoc test, significant differences among the three cities were observed in level of public knowledge [ F (2,1197) = 12.886, p < 0.05], and practice [Welch’s F (2,770.49) = 119.79, p < 0.05] on E-waste management and recycling. However, significant variations were only observed in E-waste management and recycling practices among the public between 31 to 40 age group, higher learning education, and higher income level. According to the public opinion, inadequate facilities, lack of awareness and education, insufficient recycling centres, and public ignorance towards E-waste management were the main reasons behind the unsuccessful recycling program in the study areas. Law enforcement, frequent programs on public awareness, incentives or gifts, and closer proximity of recycling centre will enhance the E-waste recycling in the study areas. The findings of this study can be utilised by the policy makers and other stakeholders so that effective steps can be taken to increase the performance of recycling among the public
Hubungan antara budaya: Kajian etnografi ke atas Kumpulan Wayang Kulit Sri Campuran Di Kelantan / Eyo Leng Yan
No full textMalaysia is of diverse backgrounds that require each ethnic group to respect, tolerate and understand other cultures in order to ensure prosperity and harmony. However, issues related to ethnic conflict have never been resolved. Studies conducted by previous researchers formulating the barriers to intercultural relations are language, culture, religion, and perception that lead to prejudice, ethnocentrism and racial polarization that hinder inter-ethnic communication. This study uses intercultural communication disciplines to see the phenomenon of an intercultural relations in the performance of the Kelantan’s Wayang Kulit performed by the Sri Campuran Wayang Kulit Group. This group was chosen as the subject of the study as the characteristics of this group have ethnic coalition, that contribute to intercultural communication. This study examines three main aspects of Kelantan's Wayang Kulit performing arts, include the cultural aspects of Kelantan community (cultural context), the Sri Campuran Kelantan Group (micro cultural context) and intercultural communication in the Kelantan's Wayang Kulit performing arts, thus forming cultural relations (environmental context). Through ethnography approach and participating observation methods in five locations of the show and interviewing methods, there is a cultural connection between various ethnic groups in Kelantan and does not raise issues related to language, culture, religion and perception
On-orbit spatial image characterisation and restoration based on stochastic characteristic targets / Wong Soo Mee
No full textWhile the qualities associated with the radiometric and geometric resolution are a major concern in earth observation satellite (EOS) imaging sensors calibration and validation, spatial resolution quality is an important parameter that is essentially needed for on-orbit spatial EOS imaging performance assessment. Moreover, its calibration results can be applied to an image restoration problem, to improve the spatial quality of the EOS data. A practical way to characterize the on-orbit spatial quality performance of an EOS imaging sensor is to determine the modulation transfer function (MTF) from its remotely sensed images on the ground. However, existing approaches and techniques for spatial characterisation are highly reliant on the presence and manual identification of a well-separated characteristics target. These approaches and techniques impose stringent criteria and temporal sampling issues. In spatial image restoration, even with the perfect estimation of degradation function, restoring coherent high-frequency image details can still be very difficult.
This thesis presents two frameworks; the first one is for on-orbit spatial characterisation, whereas the second is for optical satellite image restoration. In the first framework, this thesis introduces an insight to effectively measure the MTF by analyzing the stochastic characteristics in the observed image. In particular, first, it proposes a segmentation method to select the ideal candidates for MTF Measurement. Second, it develops an adaptive structure selection method that removes detrimental structures and selects only useful information for point spread function (PSF) estimation. Finally, it introduces a spatial prior that can simultaneously suppress noises while preserving the sparsity and continuity of data to obtain high fidelity two-dimensional PSF model for MTF measurement. The experimental results demonstrate that the proposed framework is practical and effective, with < 2.3% of relative error at the Nyquist frequency as compared to the well-established edge method.
In continuation of the first framework, the proposed MTF measurement algorithms are evaluated experimentally as a blur kernel estimation method for spatially varying and invariant blur removal. Furthermore, this thesis presents a comparative study on blur estimation methods that utilize the principle of sparse representation to gain an insight into image priors type that appropriate for blur removal in blind optical satellite images. Given the fact that the heavy-tailed properties of MTF typically introduce noise and an unacceptable aliasing effect. Therefore, in the second framework, this thesis exploits the image properties and shows that only one image property used in a regularization-based framework is insufficient to obtain satisfying restoration results. Hence, this thesis presents a strategy for high-fidelity MTF compensation by characterizing both the local smooth and nonlocal self-similarity properties of images in the hybrid domain. To minimize computational complexity, it establishes a simple joint statistical model in the Curvelet domain to combine these image properties and employ the multi-objective bilevel optimization approach to efficiently solve the severely ill-posed inverse problem of MTFC. The experimental results show that the proposed methods achieve significant performance in preserving high fidelity images with feature similarity (FSIM) index value as high as 0.99876 and minimum computational complexity
Incorporating singing as a tool for teaching phrasing among piano teachers in Klang Valley Malaysia / Ng Weng Seng
No full textOne of the main difficulties that a piano student may encounter is to shape a phrase musically. In general, these phrases may lack direction, shape and expression, thus affecting the student’s interpretation in performance. Most researchers agree that the voice is the most natural instrument and that listening to good singers will help to develop musicality and good phrasing in piano playing. The purpose of this research was to find an effective approach to incorporating singing as an aid to piano playing. This study investigated how piano teachers in the Klang Valley of West Malaysia have incorporated singing as a teaching tool in piano lessons in order to teach phrasing in music. A qualitative research approach was employed. Ten semi-structured interviews were conducted to discover the teachers’ perspectives on the use of singing as one of the tools to improve phrasing in their students’ piano playing. This was followed by 15 observations of the lessons given by five piano teachers to see how the inclusion of singing affected the students’ phrasing of the music. The results indicated that the use of singing as an aid in teaching phrasing had positive effects in terms of having a better understanding of the phrase structure, breath points, shaping, dynamic contrasts, tone colour and direction of the phrases. The results also showed that the physical gesture of breathing in singing helped to promote better phrasing and shaping in musical performance. Furthermore, the results found that listening and appreciating the elements in good singing helped the students to improve their musical interpretation and heighten their understanding of good sound. There were three novel findings, namely, listening to good classical singing would build musicianship and musicality from the early stages of music learning, singing was used to teach voicing and to improve the awareness of fingering in piano playing. This study argues that such an approach will promote better phrasing in musical performance