Repository@USM
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- PublicationAnalysis of medium rise reinforced concrete building subjected to lateral loads(2006-06-01)Since the earthquake and tsunami that happened on 26th December 2004 in Sumatra, it has increased the awareness and urged engineers in Malaysia to identify the importance of considering the earthquake impact to the building structures. In this project, a plan of a medium rise building is selected. This analysis is about the earthquake impact or seismic impact, including other forces such as wind load, gravitational load or selfweight, finishes load, life load and brick wall load with the consideration of the drift. The analysis is being done with the aid of STAAD III Release 22.3 software. From the analysis, it shows that seismic load gave that major lateral deflection to the building structure, compared to other forces such as wind loads, selfweight and live load. The total lateral deflection due to seismic load is 39.9mm while wind load is 21.5mm. As for the inter-storey drift, the value of 3mm is due to wind and 5mm for seismic load. Even though the drift is in the safe range for the structure, the drift difference for seismic load is nearly twice the wind loads. This gives an early notice in the importance of seismic loads consideration for designing any structure in Malaysia.
- PublicationAn investigation on the properties of ferrocement containing different layers of wire mesh(2006-03-01)Ferrocement, a thin wall cement mortar reinforced with wire mesh and now considered to be a very innovative construction material, was known to be used over hundred years ago. Ferrocement is the most effective route to impart outstanding crack control to the concrete matrix and through this crack control, develop excellent mechanical properties, energy absorption characteristics, toughness and impact resistance. The principle of ferrocement is to understand it mechanism whereby the reinforcement and matrix interact to distribute strains, improve first crack strength and control the size and spacing of cracks. Numerous theoretical and experimental studies have been undertaken all over the world in recent years to investigate the properties of ferrocement and explore its potential field of applications. It is obviously unrealistic to talk about ferrocement replacing reinforced concrete for all the purposes, but it is undeniable that there are many situations where the use of the ferrocement concept can be more cost effective in terms of construction costs and its service life span. It is now clear that ferrocement, a versatile construction material,has a bright prospect and will definitely find better utilization in the future.
- PublicationIdentifying The Components And Factors Of Graduate’s Employability: The Perspectives Of Policymakers, University Administrators, Undergraduates And Employers In Penang(2023-09)There numerous of study about employability has been conducted by researchers from different discipline previously. However, the research that conducted did not touch on all four stakeholders that this study looks into. Beside that, the unemployment rate of Malaysia is having the trend of increase yearly, and effort that taken are not uniform. Therefore, this study explored the concept of employability by unpacking this from the perspectives of policymakers, university administrators, employers and undergraduates. Policymakers, university administrators representatives, employer representatives and undergraduate representatives were recruited as participants in this study. These respondents were selected because they are the ones who produce the direct impact and direct beneficiary of employability. Data for policymakers was collected through the policymaker who is from the Ministry of Higher Education, whereas the university representatives are from a public research university in Penang and an international college in Penang. While for employers, the chosen employers' representatives are those who are involved directly in the recruitment process of that particular company. Lastly, student representatives are the students who are still studying at the public research university and the international college in Penang. Qualitative data were collected using semi-structured interviews as instruments. Results showed that employability is a process, and it has four characteristics which are job suitability, ability to be employed, readiness of employment and job sustainability. The study also found that employability skill can be interpreted in both the short-run and long-run. Skill-based employability and knowledge-based employability primarily contribute to short-term employability, while competence-based employability and capability-based employability, along with the other two employability types, contribute to long-term employability for graduates.
- PublicationAn investigation on the behaviours of buried structural arch culvert with varying rise span ratio(2006-03-01)Since the Romanian Empire until twentieth century, the arch structures are widely applied in all fields of engineering constructions, from bridge, subways, and underground structures to military shelters. The loadings are altered to fulfill the specific demand in transportation systems, materials quantity and the analysis methods. Therefore, we should improvise our understandings on structural behaviour. The behaviour of buried structural arch for span 10m to 30m are analyzed with finite element method. The structural behaviours include the axial force, shear force and bending moment in both distributions diagram and magnitude. By applying three types of load cases, that is self-weight, fill weight and live load, the behaviours of arch for axial force, shear force, bending moment, horizontal and vertical reaction are observed. This research provides a better understanding about the behaviours on buried arch with various rises to span ratio. From the analysis on the behaviours of buried arch by finite element method, the change in arch rise to span ratio for three types of load cases show the increment in maximum axial force, shear force, bending moment, horizontal and vertical reaction. Investigation for buried arch structures with different rise to span ratio is importance for future designs of arch structures, with higher quality, durability and strength. Lastly, future design of arch structures will be able to achieve longer life cycle, cost effectiveness and environmental friendly.
- PublicationDevelopment Of Asarone-free Piper Sarmentosum Roxb. Extracts Using Supercritical Carbon Dioxide Pre-treatment And Studies On Their Stability, Cytotoxicity And Enzyme Inhibition(2023-09)Piper sarmentosum Roxburgh is a herbaceous shrub with numerous pharmacological benefits. However, the presence of two toxic phenylpropanoids (α- and β-asarone) has limited the usage of the plant for medicinal purposes. The objectives of the present study include phytochemical analysis of supercritical carbon dioxide (SC-CO2) extract, optimization of SC-CO2 for maximum removal of α-, β- and ɣ-asarone, comparative study between SC-CO2 pre-treated and untreated P. sarmentosum leaf extracts to evaluate their metabolites profiles, bioactivities and stability. The leaves of P. sarmentosum were extracted using SC-CO2 and conventional solvent maceration method to compare the efficiency of asarone extraction. Optimization of asarone extraction was conducted using the Box-Behnken experimental design. SC-CO2 residue was re-extracted using ethanol, 50% ethanol and water, and their chemical and biological profiles were compared with those of leaf material without SC-CO2 pre-treatment. SC-CO2 extraction selectively extracted α-, β- and ɣ-asarone with more than two folds compared to conventional solvent extraction method. Gas chromatography-mass spectrometry (GC-MS) analysis of SC-CO2 extract identified α-asarone (28.18%) as the major component in the extract, followed by γ-asarone (25.70%), phytol (9.66%), asaricin (11.20%) and vitamin E (4.85%). Optimized SC-CO2 condition to maximize the extraction of α-, β- and ɣ-asarone was obtained at pressure = 81.16 bar, temperature = 50.11°C and extraction time = 80.90 min. High performance liquid chromatography (HPLC) analysis of the optimized method showed 13.91% α-asarone, 3.43% β-asarone and 14.95% ɣ-asarone, respectively. SC-CO2 residue of the leaves re-extracted with conventional solvents showed a significant decrease of asarone ranging from 45 to 100% (p<0.001) as compared to their counterpart without SC-CO2 treatment. α-, β- and ɣ-asarone were completely removed in the ethanol and 50% ethanol extracts of the residue, whereas the isomers were absent in water extract.
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- ItemMicrobiological quality of raw edible vegetables sampled from cafeterias at Universiti Sains Malaysia, Kubang Kerian, Kelantan(Pusat Pengajian Sains Kesihatan, Universiti Sains Malaysia, 2013)Raw fruits and vegetables have been known to serve as vehicles of human diseases and food borne outbreaks have increased in recent years. Raw vegetables contaminated with pathogenic bacteria may lead to health hazard as there is no treatment that can be relied upon for decontamination of the vegetables. A study was conducted to screen and identify the bacterial pathogens present in selected raw vegetables sold in the cafeterias in USM Health Campus. A total of 30 samples from six commonly consumed raw vegetables viz., cucumber, winged bean, lettuce, wild cosmos, pennywort leaves and water dropwort were analyzed. Samples were randomly collected over a period of two months. Fifty grams (50g) from each sample were taken for microbiological analysis. The presence and identification of pathogenic bacteria viz., E.coli, Bacillus cereus, Staphylococcus aureus, Salmonella and total coliforms was determined based on the "Australian Microbiological Examination of Food", (1993) and the analysis was conducted in triplicates. Compliance to the microbiological quality (CFU/g) of raw vegetables is based on the "Microbiology Guidelines for Ready to Eat Food" MOH Malaysia ( 1985). The results showed that the total coliforms were presence in all vegetables samples (~1,000 CFU/g, unsatisfactory). A total of 6 (20%) samples (1 cucumber, 1 pennywort, 3 water dropwort and 1 wild cosmos) showed presence of pathogenic bacteria namely E.coli and Salmonella. However, lettuce and winged bean did not show presence of any of the pathogenic bacteria. E. coli was detected ( 3-1 00 CFU/g , marginal) in 25% of the pennywort, 22.2% water dropwort (3x 103 -5x 1 oJ CFU/g, unsatisfactory), and 50% wild cosmos samples (1x103 CFU/g, unsatisfactory). Meanwhile, Salmonella was detected in 12.5% of the cucumber and 11.1% water dropwort samples. However, the presence of Bacillus cereus and Staphylococcus aureus were not detected in any of the raw vegetables sampled. Our findings revealed that all vegetables samples showed presence of total coliforms, and some with E.coli and Salmonella, exceeding the safe level described by "Microbiology Guidelines for Ready to Eat Food" MOH Malaysia (1985), and this can be construed that the contaminated vegetables may pose considerable hazards on human health. Furthermore, further identification has led to the detection of an enteric serovar weltevreden which has been implicated with several cases of food borne illnesses (Bangtrakulnonth, 2004). However, no pathogenic E.coli was isolated in this study. Thus, further study should be carried out to determine the source of contamination so that measures can be taken to improve the microbiological quality of raw vegetables sold in Health Campus, USM.
- ItemDesign and analysis of satellite's ground station(2018-06)Design and Analysis of Satellite’s Ground Station is a thesis project based on the development of the ground station for LEO satellite, MYSat, which is going to be launched by USM Space System Lab (USSL) in near future. The ground station consists of azimuth & elevation controller, terminal nodes controller (TNC), amplifier and pre-amplifier, rotator, a fabricated rotator-computer interface and VHF & UHF antennas that operated at dual frequencies which are 145.8 MHz and 437.45 MHz. This study investigated on the design and fabricated of rotator-computer interface, design of antennas with its supporting holder and design of ground station that includes visually integration between software and hardware. Rotator-computer interface is origin from Yaesu and is an open source device. An interface operated by Arduino Mega was designed and fabricated in this study, which allows the connection to computer simply through USB port. Coding is uploaded to the interface/Arduino that is compatible with GS232 command and allow the satellite tracking software to control both the azimuth and elevation rotators. The antenna was designed, and its performance was optimized and simulated using numerical electromagnetic code (NEC). At the end of the study, a complete ground station was designed to give vision on the integration between software and hardware, including the transmission lines used.
- ItemThe influence of different dopants substitution into carbonated htdroxyapatite (CHA) structure(2019-07)Mg-doped CHA and Sr-doped CHA were synthesized via nanoemulsion method as this method was simple and can be carried out at room temperature. In this study, different amount of carbonate was used to synthesise CHA in order to get the optimize amount carbonate. The aim of introducing magnesium and strontium into carbonated hydroxyapatite structure was to study the effect size of dopants that been introduced into apatite structure. CHA was used as a control set for Mg-doped CHA and Sr-doped CHA. CHA x = 2.4 was chosen as the optimized amount of carbonate to synthesise doped CHA. There were three different compositions of dopants were used which were 0.1, 0.2 and 0.3 in order to synthesise Mg-doped CHA and Sr-doped CHA. All the doped CHA that been synthesized remained as B-type CHA with nanosize powders. All the as-synthesized powders were characterized in terms of elementally, physically and biologically. For bioactivity test, all the powders been palletized before soaked in the Simulated Body Fluid (SBF) solution for 7 days. After soaking, all the sample have successfully formed apatite layer on the surface of pellet after observed under FESEM. Thus, Sr CHA 0.1 showed good bioactivity properties as the formation of apatite was faster compared to other samples.
- ItemPengetahuan dan praktis jururawat semasa mentafsir kesakitan angina di wad perubatan(Pusat Pengajian Sains Kesihatan, Universiti Sains Malaysia, 2003)Objektif Mengetahui pengetahuan asas jururawat berkaitan kesakitan dada dan praktis jururawat semasa menerima aduan kesakitan dada dari klien di wad perubatan. Faktor ini disebabkan jururawat memainkan peranan panting dalam penaksiran dan pengurusan semasa menerima aduan kesakitan dada daripada klien sebelum kesakitan tersebut dilaporkan kepada Pegawai Perubatan. Kajian ini telah dijalankan diwad Perubatan 7 Selatan, 7 Utara dan 8 Selatan. Kaedah Kajian Kajian yang dijalankan berbentuk soalan dimana jururawat dan Ketua Jururawat di wad Perubatan seramai 50 orang diberikan soalan berdasarkan pengetahuan dan praktis semasa menerima aduan kesakitan dada dari klien. Keputusan Kajian Keputusan kajian mengenai pengetahuan berkaitan kesakitan dada dan angina daripada 50 sampel didapati 70-90% responden memberi jawapan yang betul manakala 64-76°/o daripada responden melakukan tindakan yang betul semasa menerima aduan kesakitan dada dan angina. Walau bagaimanapun tiada hubungan statitik yang significant diantara pengetahuan dan praktis responden. Keputusan juga menunjukkan bahawa tindakan dan praktis jururawat semasa aduan sakit dadadan angina tidak m empunyai keseragaman yang tepat pad a setiap tindakan dan praktis yang diamalkan oleh mereka. Cadangan Jururawat diberi pengetahuan dan maklumat tambahan mengenai kesakitan angina dan cara mentafsir kesakitan angina mengikut carta khas yang diserangam ke seluruh wad perubatan. Bagi jururawat yang berminat menyambung pendidikan pihak pengurusan seharusnya mengalu-alukan hal tersebut kerana hasil kajian menunjukkan jururawat yang mempunyai kursus pas basik iaitu Diploma pengkhususan dan Rawatan Koronori lebih berpengetahuan semasa menilai dan mentafsir kesakitan angina di kalangan klien. Kesimpulan Berdasarkan kepada keputusan kajian, menunjukkan bahawa sememangnya jururawat tidak mempunyai ketidakseragaman dalam mentafsir dan melakukan praktis semasa menerima aduan kesakitan dada dari klien. Majoriti jururawat melakukan tindakan hanya berdasarkan amalan tanpa pengetahuan.
- ItemExperimental Study On Ai2o3-Tio2 And Ai2o3-Cuo Hybrid Nanofluids For Lithium Ion Battery Cooling(Universiti Sains Malaysia, 2021-03-01)Lithium ion battery (LIB) is widely used in electric vehicles (EVs) and hybrid electric vehicles (HEVs) due to its high energy density and low charge loss when not in use. However, the use of high energy density LIB has thermal runway risk, which requires an effective thermal management system. This research focuses on formulating hybrid nanofluids and evaluating the thermal performance of hybrid nanofluids for cooling LIB cells. Two different types of hybrid nanofluid containing Al2O3, TiO2, and CuO nanoparticles are developed using water and water/EG as the base fluid. The Al2O3, TiO2, and CuO nanoparticles were characterized using XRD and FESEM technique. The effect of nanoparticle mixture ratio and volume concentration on the thermophysical properties are investigated experimentally at temperatures between 30 to 70ºC. Based on the experimental data, regression analysis was performed to model new correlations that can be used to estimate the thermal conductivity and dynamic viscosity of TiO2-Al2O3/water and Al2O3-CuO/water-EG hybrid nanofluid. The average crystallite size of Al2O3, TiO2, and CuO nanoparticles calculated using the XRD data is about 8, 19, and 24 nm, respectively. The Al2O3-CuO hybrid nanofluid achieved the maximum thermal conductivity enhancement of 12.32% for the mixture ratio of 60:40. In contrast, the TiO2-Al2O3 hybrid nanofluid recorded the maximum thermal conductivity enhancement of 66.5% for the mixture ratio of 50:50 at a temperature of 70ºC. Besides, the dynamic viscosity results show that TiO2-Al2O3/water nanofluid has lower viscosity compared to Al2O3-CuO/water-EG hybrid nanofluid. The correlation model were developed for thermal conductivity and viscosity estimation indicates a good agreement between the experiment and predicted data with a standard error of less than 10%. The thermal performance of both nanofluids is tested using a novel thermal management system developed based on a liquid cooling system using mini channelled cooling block. The effect of nanofluid volume concentration and volumetric flow rate on the cooling performance of LIB was tested experimentally. The TiO2-Al2O3 hybrid nanofluid showed an excellent cooling performance with 74.9% enhancement in the heat transfer coefficient compared to the base fluid. The use of TiO2-Al2O3 hybrid nanofluid reduces the LIB temperature by about 12.35ºC compared to Al2O3-CuO hybrid nanofluid, which can only reduce 10.06ºC. The friction factor computed for the TiO2-Al2O3 hybrid nanofluid is significantly lower than the Al2O3-CuO hybrid nanofluid. The use of hybrid nanofluid was able to maintain the temperature of the LIBs at safe operating temperature and has a high potential to be used in cooling LIB module for EVs and HEVs.