Replacing Self-Balancing System of Personal Transporter by Using Gyroscope

The methodology selected is by exploring various balancing system that are available in the market nowadays, and analyze those balancing system to establish design specification and criteria for this project system

Characterization of Palm Oil Ashes (POA) under Impulse

The characteristics of soils as used in earth electrode systems were investigated. In this project, the material proposed is palm oil ashes. The work involved particle size distribution, moisture holding capacity, compactness and also breakdown voltage under impulse. For particle size distribution, moisture holding capacity and compactness tests, it had been conducted in Geotechnic Lab, Faculty of Civil Engineering, UTM. The size chosen for every test in this project was 600μm and below. Meanwhile, for a breakdown under impulse test, it had been conducted in IVAT building, FKE. The particle chosen were 600μm because after the particle size distribution test, it is found, it covered 74% from the total of 300g POA. As for moisture holding capacity, it is found, that it can absorb 150% water referring to its dry mass. In the compaction test, the result shows that the optimum compacted are at 25% water added. As for the breakdown voltage impulse, it is found that the breakdown voltage of wet soils is always lower than the dry soils

Morus alba L. : creating miles of smiles / Nurhayati Mohamad Zain … [et al.]

The aims of the study are to determine the antimicrobial and antibiofilm activities of M. alba leaves extract against Streptococcus mutans (S.mutans). Method: The antimicrobial activity was evaluated using minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The antibiofilm potential of extract was evaluated using biofilm inhibition assay and biofilm eradication assay. Oradex mouthwash with 0.12% CHX was used as a positive control. All experiments were performed in triplicate and repeated four times independently. Data were analysed using SPSS software version 23. A Kruskal-Wallis test followed by post-hoc Mann-Whitney U test was applied and level of significance was set at P < 0.001. Results: Morus alba (M.alba) leaves extract showed antimicrobial activity against S.mutans with MIC and MBC, 25mg/ml and 50mg/ml respectively. The adherence of bacteria on extract treated surface (0.5x MIC) was significantly reduced with adherence inhibition percentage of 72.5% compared to positive control CHX 0.12% (63%). At 0.5x MIC concentration, the extract also disrupted preformed biofilms with eradication percentage of 52.87%. Conclusion: The results suggest that M. alba leaves extract represents an untapped source of local plant with antibiofilm activity against S.mutans that could be a resource in the development of therapeutic natural products in managing dental caries

Review of the Common Deposition Methods of Thin-Film Pentacene, Its Derivatives, and Their Performance

Pentacene is a well-known conjugated organic molecule with high mobility and a sensitive photo response. It is widely used in electronic devices, such as in organic thin-film transistors (OTFTs), organic light-emitting diodes (OLEDs), photodetectors, and smart sensors. With the development of flexible and wearable electronics, the deposition of good-quality pentacene films in large-scale organic electronics at the industrial level has drawn more research attention. Several methods are used to deposit pentacene thin films. The thermal evaporation technique is the most frequently used method for depositing thin films, as it has low contamination rates and a well-controlled deposition rate. Solution-processable methods such as spin coating, dip coating, and inkjet printing have also been widely studied because they enable large-scale deposition and low-cost fabrication of devices. This review summarizes the deposition principles and control parameters of each deposition method for pentacene and its derivatives. Each method is discussed in terms of experimentation and theory. Based on film quality and device performance, the review also provides a comparison of each method to provide recommendations for specific device applications

Effect of laser frequency and focal length on copper surface temperature during laser heating

Laser heating is a process that uses laser as a heat source. In this paper, the copper surface temperature during the laser heating process was studied by controlling the laser frequency and focal length. The laser heating experiment was conducted using a fiber laser marking machine and irradiated with a constant 27 W laser power within a duration of 51 s. The laser frequency and focal length were varied from 100 to 300 kHz and −3 cm to +3 cm, respectively. Meanwhile, laser surface modification (LSM) was performed on the copper rod surface to enhance the laser energy absorption. Furthermore, the defocusing modes for laser heating were used to analyze the variation of temperature. The focus point of the focal length for this experiment was set up at 18.4 cm from the focal plane and denoted as 0. Laser frequency and focal length were found to play an important role in increasing the surface temperature during laser heating since it affects the heat input delivered to the materials. It was found that the surface temperature reaches a higher degree, 879.2 °C with the combination of 200 kHz laser frequency at focal length

Elucidating on Time and Temperature Effects on Torrified Moldy Bread

Waste-to-energy is the preferred solution, according to the waste management hierarchy considering landfill waste disposal may not be the most effective method of waste usage. Torrefaction of kitchen waste to produce higher-quality solid fuels is an effective option with lower temperature requirements than pyrolysis and gasification. By addressing the problems, the fuel quality in terms of high heating value can be investigated. Also, the torrefaction parameters, temperature and time, can be examined on the fuel performance. The moldy bread undergoes torrefaction by torrefying it in the furnace with temperatures of 200, 250 and 300°C, respectively, with 15, 30, 45 and 60 mins of processing times. With increased torrefaction temperature, the mass dropped while the higher heating value (HHV) increased. The rise in carbon content also enhanced the torrefied moldy bread's fuel properties. Also, this is because the primary components of the moldy bread, particularly hemicellulose, have significantly decomposed. Therefore, processed temperature of 300°C at elevation time of 45 min produced tremendous gain than other parameters observed

Experimental Investigation of Thermal Fatigue Die Casting Dies by Using Response Surface Modelling

Mechanical and thermal sequences impact largely on thermo-mechanical fatigue of dies in a die casting operations. Innovative techniques to optimize the thermo-mechanical conditions of samples are major focus of researchers. This study investigates the typical thermal fatigue in die steel. Die surface initiation and crack propagation were stimulated by thermal and hardness gradients, acting on the contact surface layer. A design of experiments (DOE) was developed to analyze the effect of as-machined surface roughness and die casting parameters on thermal fatigue properties. The experimental data were assessed on a thermo-mechanical fatigue life assessment model, being assisted by response surface methodology (RSM). The eminent valuation was grounded on the crack length, hardness properties and surface roughness due to thermal fatigue. The results were analyzed using analysis of variance method. Parameter optimization was conducted using response surface methodology (RSM). Based on the model, the optimal results of 26.5 μm crack length, 3.114 μm surface roughness, and 306 HV0.5 hardness properties were produced

Thermally-Induced Crack Evaluation in H13 Tool Steel

This study reported the effect of thermal wear on cylindrical tool steel (AISI H13) under aluminum die-casting conditions. The AISIH13 steels were immersed in the molten aluminum alloy at 700 °C before water-quenching at room temperature. The process involved an alternating heating and cooling of each sample for a period of 24 s. The design of the immersion test apparatus stylistically simulated aluminum alloy dies casting conditions. The testing phase was performed at 1850, 3000, and 5000 cycles. The samples were subjected to visual inspection after each phase of testing, before being examined for metallographic studies, surface crack measurement, and hardness characteristics. Furthermore, the samples were segmented and examined under optical and Scanning Electron Microscopy (SEM). The areas around the crack zones were additionally examined under Energy Dispersive X-ray Spectroscopy (EDXS). The crack’s maximum length and Vickers hardness profiles were obtained; and from the metallographic study, an increase in the number of cycles during the testing phase resulted in an increase in the surface crack formation; suggesting an increase in the thermal stress at higher cycle numbers. The crack length of Region I (spherically shaped) was about 47 to 127 µm, with a high oxygen content that was analyzed within 140 µm from the surface of the sample. At 700 °C, there is a formation of aluminum oxides, which was in contact with the surface of the H13 sample. These stresses propagate the thermal wear crack length into the tool material of spherically shaped Region I and cylindrically shape Region II, while hardness parameters presented a different observation. The crack length of Region I was about 32% higher than the crack length of Region II

Fiber Laser Welding of Dissimilar 2205/304 Stainless Steel Plates

In this study, an attempt on pulsed-fiber laser welding on an austenitic-duplex stainless steel butt joint configuration was investigated. The influence of various welding parameters, such as beam diameter, peak power, pulse repetition rate, and pulse width on the weld beads geometry was studied by checking the width and depth of the welds after each round of welding parameters combination. The weld bead dimensions and microstructural progression of the weld joints were observed microscopically. Finally, the full penetration specimens were subjected to tensile tests, which were coupled with the analysis of the fracture surfaces. From the results, combination of the selected weld parameters resulted in robust weldments with similar features to those of duplex and austenitic weld metals. The weld depth and width were found to increase proportionally to the laser power. Furthermore, the weld bead geometry was found to be positively affected by the pulse width. Microstructural studies revealed the presence of dendritic and fine grain structures within the weld zone at low peak power, while ferritic microstructures were found on the sides of the weld metal near the SS 304 and austenitic-ferritic microstructure beside the duplex 2205 boundary. Regarding the micro-hardness tests, there was an improvement when compared to the hardness of duplex and austenitic stainless steels base metals. Additionally, the tensile strength of the fiber laser welded joints was found to be higher when compared to the tensile strength of the base metals (duplex and austenitic) in all of the joints

Penulisan dan kajian berkaitan Tuan Guru Nik Abdul Aziz Nik Mat (1931-2015): Analisis bibliometrik sepanjang tiga dasawarsa: Writings and studies related to Tuan Guru Nik Abdul Aziz Nik Mat (1931-2015): Bibliometric analysis over three decades

Scholars play a significant role in a community so that they can form a knowledgeable, virtuous, and civilised society. The spread of Islam and intellectual interweaving from the Middle East had a positive impact until the emergence of authoritative scholars in the archipelago. Among the Nusantara scholars was Tuan Guru Nik Abdul Aziz Nik Mat (TGNA), an influential scientist who played a major role in the fields of science, preaching, education, administration, and politics. His vast influence across so many fields has attracted the interest of many scholars to study his life and his legacy. This paper aims to identify writings and studies related to TGNA over three decades, from the 1980s to the 2000s. The methodology used was based on bibliometric analysis methods for writing and research, whether in the form of theses, dissertations, books, or scientific articles. These data were obtained from databases of scholarly articles and libraries, and the website of the Tuan Guru Nik Abdul Aziz Nik Mat Institute of Thought (TPTG). The results found that studies and literature about TGNA have been written since the late 1980s and are still being written until now. Up to the time that the present study was conducted, a total of 131 writings and studies about TGNA had been presented in Malay and English, and published locally or abroad. The findings of this study can provide a general overview of the current writing and research trends about TGNA and the direction of future research related to it