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MHD boundary layer flow due to an exponentially stretching sheet with radiation effect
No full textThe effect of radiation on magnetohydrodynamic (MHD) boundary layer flow of a viscous fluid over an exponentially stretching sheet was studied. The governing system of partial differential equations was transformed into ordinary differential equations before being solved numerically by an implicit finite-difference method. The effects of the governing parameters on the flow field and heat transfer characteristics were obtained and discussed. It was found that the local heat transfer rate at the surface decreases with increasing values of the magnetic and radiation parameter
Assessment of knowledge, attitudes and practices (KAP) among food handlers at residential colleges and canteen regarding food safety
No full textresidential colleges and canteen in the main campus of Universiti Kebangsaan Malaysia regarding the aspect of food hygiene and safety. Sixty five food handlers from two residential colleges’ cafeterias and one Faculty of Science and Technology’s canteen were involved in the study. The data were collected from the food handlers through the methods of questionnaire and analyzed using the SPSS version 12.0. In general, the respondents’ knowledge was moderate with mean point of 57.8%. However, they have good knowledge on personal hygiene and definition of foodborne diseases with mean point of 93.85% and 73.85%, respectively. On the contrary, their knowledge on food storage and preparation temperatures was poor with only 28%. Respondents showed positive attitudes towards two categories of questions in the aspect of food safety and hygiene (76.9%); foodborne prevention and control (70.8%). Majority of the respondents have an average practices in all parts of the questions. Analysis tests showed significant difference (p<0.05) between the relationship of respondents’ knowledge with their working experiences (p=0.008), attitudes with training attended (p=0.006) and practices with gender (p=0.032). There was significant difference for knowledge based on cafeteria (p=0.000). In conclusion, amongst the three levels, respondents showed only good attitudes in food handling and all the cafeterias in this survey need to increase the hygiene level of their food handlers’ hand and environment of the premises
Kajian faktor-faktor fizikal terhadap tahap keselesaan bekerja di Bahagian Casting Shop di kalangan pekerja di Kilang Pembuatan Kereta
No full textBackground : Level of comfort in working environment can contribute to increase level of health, emotion during working, level of safety, quality and productivity of work. A study of physical factors (heat, noise and lighting) is important to determine the level of comfort during working. This study was carried out to study those physical factors upon comfort level during working among Casting Shop workers in a car manufacturing factory.
Methods : Instruments for the physical monitoring including Questemp°36 Thermal Environment Monitor, Sound Level Meter and Lux Meter were used at seven measured areas. The information about the level of comfort during working was collected using questionnaires among 65 respondents by random sampling method.
Results : Measured data showed there were four measured areas which Wet Bulb Globe Temperature indoor (WBGTi) value are above the standard limit recommended by ACGIH, three measured areas recorded noise level above the standard limit recommended by Factories and Machineries (Noise Exposure) 1989, while there was no measured area recorded lighting reading below the standard limit recommended by MS ISO 8995:2005. Result from questionnaire found that the majority of the workers did not feel comfortable towards the heat and noise level in their workplace while most of the respondents felt comfortable towards lighting level in their workplace. Mean of WBGTi reading and lighting reading have a significant difference (p<0.05) between half of those measured areas. Mean of noise reading also has a significant difference (p<0.05) between those measured areas. This study also found that there was a relationship between level of health, emotion during working, level of safety, quality and productivity of work and.
Conclusion : This study shows that the physical factors influenced the level of comfort during working among Casting Shop workers
Ion conductive polymer electrolyte membranes and simulation of their fractal growth patterns
No full textDue to their high ionic conductivity, solid polymer electrolyte (SPE) systems have attracted wide spread attention as the most appropriate choice to fabricate all-solid-state electrochemical devices, namely batteries, sensors and fuel cells. In this work, ion conductive polymer electrolyte membranes have been prepared for battery fabrication. However, fractals were found to grow in these polymer electrolyte membranes weeks after they were prepared. It was believed that the formation of fractal aggregates in these membranes were due to ionic movement. The discovery of fractal growth pattern can be used to understand the effects of such phenomenon in the polymer electrolyte membranes. Digital images of the fractal growth patterns were taken and a simulation model was developed based on the Brownian motion theory and a fractal dialect known as L-system. A computer coding has been designed to simulate and visualize the fractal growt
Accumulation of setting particles in some coral reef areas of Peninsular Malaysia
No full textThe aim of this study was to determine the accumulation of settling particles in coral reefs of Peninsular Malaysia. Settling particles were collected from the coral reefs of Port Dickson, Pulau Langkawi, Pulau Tioman, Pulau Redang and Pulau Tinggi from 2005 to 2008. The average total settling particles in Pulau Langkawi and Port Dickson was 49.8 mg/cm2/day, while for Pulau Tioman, Pulau Redang, and Pulau Tinggi was 3.5 mg/cm2/day. The results showed that accumulations rate in west coast were higher than east coast of Peninsular Malaysia. However, Pulau Tioman in the east coast received high accumulations rate of settling particles in certain times of the year due to sediment resuspension at shallow reefs caused by high energy seasonal yearly wave and monsoo
Effects of liquid natural rubber (LNR) on the mechanical properties of LNR toughened epoxy composite
No full textThe effects of liquid natural rubber (LNR) on the morphology and mechanical properties of rubber modified epoxy were investigated. Epoxy composites were prepared in four different compositions of LNR (3, 5, 7 and 9phr) by using twin screw extruder. The samples for tensile, fracture toughness and impact tests were prepared according to ASTM D 638, D 5045 and D 256. The elastomeric nature of rubber can act as energy dissipating centre to cause the ductile fracture for the rubber modified epoxy. They was an obvious increment of fracture toughness where maximum value was observed with 3 phr LNR. A clear increment of impact strength at 3 phr LNR was observed, followed by a small increment at 5 phr and no further increment at 7 and 9 phr LNR. The tensile strength showed a similar trend with impact strength and Young’s modulus. SEM micrographs showed an increment of rubber particle size when the amount of LNR was increased and caused the mechanical properties to drop
Sikap dan motivasi murid Iban dalam mempelajari bahasa melayu sebagai bahasa kedua
No full textThe aim of this study is to identify the attitude and motivation among Iban
pupils in primary school in the learning of Malay Language as a second language. This
study tries to identify the existance of differences in attitude and motivation between the
two genders of Iban pupils in the learning Malay Language. 302 year 6 Iban pupils from
15 schools in the Kanowit district were selected as respondents using the purposeful
sampling method. This study was carried out using the Gardner Socio-Educational
Model. Questionnaire consisting of 36 items was distrubet to collect data for this study.
These items were divided into attitude and motivation contructs. The data were analyzed
by using descriptive and inferential statistics. The result of the study shows that Iban
pupils in the primary schools have positive attitude and high motivation level in the
learning of Malay Language as a second language. However, the level of motivation is low
when they have to spend more time to study the Malay Language as compared to other
subjects. This study also reveals the significant differences in motivation level between
male and female pupils in the learning of Malay Language. The conclusion is Iban pupils have positive attitude and high motivation level while studing Malay Language inside or
outside the classroo
Ionic conductivity of PEMA-LiClO4 polymer electrolytes
No full textSolid polymer electrolytes comprised of various weight percent ratios of poly(ethyl methacrylate) (PEMA) and lithium perchlorate (LiClO4) salt were prepared via solution casting technique using N,N-dimethylformamide (DMF) as the solvent. The conductivity values of the electrolytes were determined via impedance spectroscopy. The conductivity of the PEMA-LiClO4 electrolytes increased with increasing salt concentration and the highest conductivity obtained was in the order of 10-6 S cm-1 at salt concentration of 20 wt%. The conductivity decreased for higher salt concentration. In order to understand the conductivity behavior, XRD and dielectric studies were done. The results showed that the conductivity was influenced by the fraction of amorphous region and number of charge carriers in the system. The transference number measurement was also performed on the highest conducting electrolyte systems. The result of the measurement indicated that the systems were ionic conductors
Kesan pewartaan taman laut ke atas penduduk Pulau Tinggi, Mersing, Johor
No full textMarine Park Malaysia is endorsed under Section 41- 45 Fishing Act 1985. Realization of the Marine Park Malaysia in 1994 brings 40 islands under its protected area. Among these are islands of Pulau Redang and Pulau Perhentian in Terengganu, Islands of Payar in Kedah, the islands of Tioman in Pahang and islands of Pulau Tinggi in Johor. The establishment of Marine Park Malaysia is to protect and conserve various habitat and aquatic marine life especially coral, flora and fauna. Marine Park Malaysia is endorsed by law and legislation to protect the natural resources around the island and its surrounding. Declaration of Pulau Tinggi as the Marine Park has honoured the efforts to protect natural heritage as well as to enhance the economy of the local people. However, it also has caused some problems to the people inhabiting these islands. This article examines the steps taken to gazette Pulau Tinggi islands as a Marine Park and its impact on the local peoples. It also discusses problem and challenges faced by the peoples as a result of its endorsement under the protected area of Marine Par
Chromium(III) based Ziegler-Natta catalysts for olefin polymerization
No full textFour chromium based oxo-trinuclear carboxylate complexes were prepared by reacting chromium(III) nitrate nonahydrate with acetic acid and substituted carboxylic acids. They were characterized using infrared spectroscopy (FT-IR). Chromium content of the complexes was determined by titrimetry method. The chromium(III) monochloroacetate complex, [Cr3O(ClCH2COO)6.3H2O]NO3.3H2O in combination with diethylaluminium chloride formed heterogeneous catalyst system for ethylene polymerization. Both Al/Cr ratio and temperature influenced the catalytic activity. The maximum activity was 1768 gPE/gCr/hr/atm, achieved by polymerizing at 29°C and monomer pressure around 1 atm, with Al/Cr ratio 30.8. Effect of chloro-substituent groups on carboxylic ligand was studied by comparing the catalytic acitivities of chromium(III) monochloroacetate, chromium(III) dichloroacetate, chromium(III) trichloroacetate and chromium(III) acetate.The polymerization reaction was found to be first order with respect to the monomer during the initial stage. The activity decreases very rapidly presumably due to fast decay of the active sites. The polyethylene was characterized using FT-IR and DSC, and the results showed that it was of high density and crystallinity