50 research outputs found
Investigating students’ perception towards economics education / Azniza Ahmad Zaini, Roslilee Abdul Halim and Zulkifli Ab. Ghani Hilmi
This paper investigates the perception and attitudes of non-business major students in Universiti Teknologi MARA (UiTM) towards economics education and their relationship on students’ academic performance. One of the key performance indicators in the academic programme of the university is to achieve less than twenty percent failures in all subjects offered. A four-semester examination results revealed that students constantly obtained high failure rate in two economics introductory subjects. Using students taking these two economics courses as respondents, dimensions of attitudes towards economics education were identified through the use of an exploratory factor analysis. Four factors were extracted from a 26-item questionnaire identified as ‘Value’, ‘Difficulty’, ‘Cognitive’ and ‘Affective’. Cronbach’s Alpha for the four factors was acceptable. The findings suggested that there was no significant difference between male and female students on the four dimensions of attitude even though the achievement of female students’ was higher than males. Students who did not perform were found to have a more negative attitude on the four dimensions of attitude compared to those who performed. Regression of the final exam scores on the four latent variables obtained from the factor analysis revealed that subject difficulty and gender, taken together, were significantly associated with students’ achievement
Optimization of food waste utilization in the RDF recovery energy facility
It is well known that there is a significant increased in the quantity of Municipal Solid Waste (MSW) generated every year. Therefore, the management of MSW must be handled carefully by experts. Malaysia as one of the developing country with population nearly 30 millions also facing problems related to MSW management and this issue is quite critical. Even though various programmes were established and few model technologies were introduced by the government to manage MSW effectively, but the impact remain unsatisfaction. For example, the energy facility recovery project which use MSW gathered around Kajang as an alternative fuel still not successful to provide energy according to the design capacity of that particular facility. This failure was observed due to the impact composition of MSW collected which consists huge amount of food waste (57%), 16% plastic, 15% diaper, 9% mixed papers and the remaining 3% textile. The existing process technology at Refused Derived Fuel (RDF) facility is no designed to create a new economic benefit from abundant incoming food waste to the facility. Therefore in this paper, the analysis and suggestion of technology on existing RDF recovery energy facility will be discussed especially on how to overcome the abundant composition of food waste
Sugar utilization in fermentation of nipa frond sap by saccharomyces cerevisiae
In recent years, concerns about the reduction of energy and materials, as well as limits to the ecosystem's assimilation capacity of residues have been raised in the social, political and business arena. All fossil fuels and minerals are limited and non-renewable on a human scale. These resources are thus limited physically and more stringently, economically [1]. Dependency on fossil fuel as energy source increase the oil price and often leads to economic depressions. In addition, the gas emission produced by the combustion of fossil fuels also contributes to air pollution and global warming. Most countries also experience more and more international pressure on global warming issues. Hence, renewable and clean alternative fuels have received increasing attention for present and future utilization [2]
Analysis of ferroresonance effect in power transformer
Ferroresonance phenomenon normally might occur in circuit that contains non-linear inductances, capacities, voltage source and small losses. The formation of Ferroresonance effect and Ferroresonance overvoltage become more topical problem today. Then by lowering of power losses during electric power transmission, system might become more sensitive on the consequences of different transient progresses. It is important to give an appropriate extra attention to the analysis and outline of simulation with the usage the most accurate mathematical models, which allow us to study the behavior of ferroresonance circuit without any risk. This paper shows a development effort to study and assess various impacts of ferroresonance phenomenon on operating performance of power transformers and to investigate ways to mitigate the effects of such phenomenon. This study used three-phase core type of transformer. The example of formation and process of ferroresonance effect in the part of power system and use of simulative software PSCAD will be described in detail in this thesis. The results of the technical investigation and the associated ferroresonance simulation work by PSCAD showed that ferroresonance can cause dangerous overvoltages and overcurrents in three-phase core type transformers
The analysis of grid independence study in continuous disperse of MQL delivery system
A sustainable cutting method of Minimum Quantity Lubricant (MQL) was introduced to promote lubrication effect and improve machinability. However, its performances are very dependent on the effectiveness of its mist to penetrate deep into the cutting zone. Optimizing the MQL system requires massive experimental work that increases cost and time. Therefore, this study conducts Computational Fluid Dynamic (CFD) analysis using ANSYS Fluent and focuses on the grid independence study in dispersed-continuous phase of MQL delivery system. The main aim is to identify the best mesh model that influences the accuracy of the CFD model. The analysis proposed two different unstructured grid cell elements of quadrilateral and triangular that were only applicable for 2-dimensional fluid flow in CFD. The unstructured grid was controlled with three different mesh quality factors such as Relevance Center, Smoothing, and Span Angle Center at coarse /low, medium, and fine /high. The results showed that the best mesh quality for quadrilateral was at 60,000 nodes number and coarse mesh, whereas the triangular was at 90,000 nodes number and coarse mesh. Both combinations resulted the most consistent and reliable result when compared with past studies. However, this study decided to choose quadrilateral cell element with 60,000 nodes number and coarse mesh as it is considered to be sufficient to provide accurate and reliable result as well as practical in terms of computational time for the MQL model in CFD analysis
Finite Element Analysis of Proximal Cement Fixation in Total Hip Arthroplasty
Total hip arthroplasty (THA), or surgical replacement of
the hip joint with a prosthesis, is a reconstructive procedure that has
improved the management of hip joint diseases that have responded poorly to
conventional medical therapy. There are reasons to believe that the proximal
part of the cement withstands more stress than the distal part in THA.
Therefore, this study aims to determine whether it is possible to perform THA
by cementing only the proximal part of the hip prosthesis. The
polymethylmethacrylate cement has a Young’s modulus of 2GPa, a tensile strength
of 29 MPa, and a Poisson’s ratio of 0.3. This analysis was done using a
stainless steel stem model provided by the Department of Orthopaedic Surgery,
University of Malaya Medical Centre, using a Young’s modulus of 200 GPa and a
Poisson’s ratio of 0.28. The bone cement was modelled while the THA femur was
reconstructed by inserting stem prosthesis into the femoral canal. The effects
of different proximal cement lengths in THA were investigated by analyzing the
stress distribution and displacement of the THA model during walking and stair
climbing
Mesh independence study on CFD for Cryo-CO2 cooling strategy
This study conducts comprehensive mesh independence tests to identify the optimum mesh independence parameters that offer the most feasible Computational Fluid Dynamic (CFD) analysis on cryo-CO2 temperature variations and its heat transfer performance under cryo-CO2 cooling strategy in metal cutting. ANSYS Fluent was used to conduct the CFD study with its mesh control parameters (relevance center and smoothing) designed using Response Surface Methodology (RSM) under Central Composite Design (CCD). An Analysis of Variance (ANOVA) was applied to analyse how the controlled factors influenced the cryo-CO2 flow temperature when it flowed from the nozzle to the tooltip. The analysis found that the relevance centre was more significant in influencing the accuracy of the response value. For optimization, the combination of medium relevance center and smoothing meshes was suggested to develop the lowest cryo-CO2 flow temperature at 256.85 K. This is crucial since most machining outputs are heat dependent. Experimental data sets were used to validate the predicted result. Distances between 3.6 to 18 mm showed an acceptable deviation of ~0.4 – 0.6% and ~0.4 – 4.2% for simulated and experimented work, respectively. This value is acceptable, and the generated quadratic model equation can be applied for prediction. The heat transfer performance of the cryo-CO2 flow at tool-chip and tool-workpiece interfaces under high-speed machining was also discussed. Moreover, further analysis using the optimal solution has led to a better understanding of heat transfer in cryogenic carbon dioxide (CO2), resulting in enhanced cooling of the cutting zone and improved machining processes
Small Cell Neuroendocrine Tumour of Bladder: A Rare Entity and Review of the Literature
Small cell neuroendocrine cancer of the bladder (SCNCB) is a rare tumor with highly aggressive characteristics and poor differentiation. It comprises less than 1% of bladder malignancy and usually diagnosed at an advanced stage. It is challenging to differentiate between SCNCB with other bladder tumors as they had a similar presentation. We presented a case of a 60-year-old gentleman who presented with painless hematuria and ultrasound and cystoscopy examination show mass on the right urinary bladder wall. Computed tomography revealed urinary bladder mass with invasion to the prostate. Histopathological examination after transurethral resection of bladder tumor display features consistent with small cell neuroendocrine carcinoma with muscularis propria invasion, positive for synaptophysin, chromogranin A and p53 in immunohistochemistry. The patient currently underwent neoadjuvant chemotherapy with Etoposide and cisplatin for 4-cycles. We, with this, presented a rare case of SCNCB, along with a discussion on the clinical presentation, histological characteristics, management, and prognosis
Assessment of Copper and Zinc Concentrations in Anadara granosa
Due to economic growth and increased human activities, large amounts of metal pollutants have been discharged into the aquatic environment. Anadara granosa, which is a filter feeder cockle species, can act as an indicator to evaluate the presence of metal elements. It is a prominent cockle species and an important protein source in Southeast Asia. Thus, this study aims to evaluate the distributions of metal elements in commercialised Anadara granosa sampled from Jeli wet market, and to assess the safety of consumption using Target Hazard Quotients (THQ). The concentrations of Cu, and Zn in those samples were determined using the acid digestion method, which has been verified with standard reference material. Based on the findings, metal concentrations in Anadara granosa followed the order of; Zn > Cu. The differences in metal accumulation observed in Anadara granosa were probably due to the differences in their environmental conditions. Results from preliminary risk assessments suggest that the risks posed by metals via consumption of Anadara granosa for Cu and Zn were within the tolerable region. The Hazard Quotient (HQ) of, Cu and Zn was < 1, indicating no potential human health risk. However, it is advisable to limit the intake of Anadara granosa to reduce the risk of potential health effects
Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis
BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London