Malaysian Journal of Applied Sciences (Journal of UniSZA - Universiti Sultan Zainal Abidin)
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Environmental Management on Natural Lake Using Sediment and Hydrology Hydraulic Models
Full text linkThe hydrology hydraulic model is established to assess environmental information on hydrology which can be used to investigate causes of various environmental problems at the river and natural lake catchment. This study reports on sediment concentrations at a river using a gravimetric method to investigate the hydrology system at a lake catchment. The measurement was carried out at the upstream, midstream, and downstream stations on the river in normal, rainy and post-rainy seasons. The stations are located along the Chini River, which are connected to a catchment lake (located at latitude 3°26’36.41”E-3°27’03.26”E and longitude 102°54’31.94”N-102°53’35.49”N). From the measurements, it is estimated that on average 787.621 tonne/km2 of sediment is transferred into the natural lake via Chini River annually. The correlation of statistical analysis between the sediment load and discharge study was very significant (R2 = 0.980). There is a linear relation between the area of the catchment and sediment load of the connecting river as supported by other studies in Malaysia. The outcome of the study suggests that the high sedimentation is due to land use activity, existence of the dam at the downstream of Chini River that traps the sediment, reverse flow from the Pahang River into Chini River and riverbank erosion factors. From this study, the sediment control steps are suggested such as creating conservation partially at the lake catchment, modifying the dam system, riverbank erosion control, and application of “Monkey Cheek” system. These sediment control steps may help to clean up the high suspended sediment at the whole lake system area, hence solving and mitigating the environmental problems in the natural lake catchment.
Aquaponics Recirculation System: A Sustainable Food Source for the Future Water Conserves and Resources
Full text linkThe current and escalating extent of soil degradation, water scarcity and environmental concern plaguing agricultural productivity, demands re-assessing the direction of food production. Aquaponics is a concept relatively new to modern food production methods and can contribute to food security. This study was conducted to establish sustainable aquaculture systems that maximize benefits and minimize the accumulation of detrimental compounds and other types of negative impacts on both natural and social environments. This study carried out at an average inflow rate of 1.28 m/day to evaluate the operation of the aquaponics recirculation system (ARS) on nutrients removal and growth and yield of African catfish as well as water spinach. A special design of ARS was used to provide nitrification of fishery wastewater, where the combination of sands and gravels in hydroponics trough, providing both surfaces for biofuel development and cultivation area for plants. Removal efficiencies of 5-day biochemical oxygen demand (BOD5), total suspended solids (TSS), total ammonia nitrogen (TAN), nitrite-nitrogen (NO2-N), nitrate-nitrogen (NO3-N), and orthophosphate (PO43-) were 82%, 89%, 93%, 94%, 81%, and 80%, respectively. The feed conversion ratio (FCR) and specific growth rate (SGR) of African catfish were 1.08 and 3.34% day-1, respectively. The average water spinach production was 3.56 kg per m2. This study showed that ARS is a method of producing crop along with a healthy protein source and among the best alternatives for achieving economic and environmental sustainability. Keywords: African catfish; aquaponics recirculation system; food security; hydroponics; water spinac
An Analysis of Determination for Life Insurance Premiums: The Concept and Practice of Conventional and Islamic Life Insurance (Family Takaful)
Full text linkThis paper aims to analyze the distinction of premium setting rates by taking into account the risk taken by conventional and Family Takaful. This study employed the Net Single and Annual Level Premium formula, and the data were analyzed using a numerical simulation. We found that the conventional and Takaful insurance systems utilize similar methods in the calculation of insurance premium when considering pure risk faced by the participant or insured. However, both systems have their own unique characteristics. The conventional and Family Takaful utilize historical data, such as mortality rate, expected return rate, expected costs and expected amount of claims. The conventional insurance is calculated to mitigate or minimize the risk of the insurance company against an amount of claim faced in the future as long as the insurance is enforced until the contract ends. On the other hand, the Family Takaful is intended to share fair value among participants in determining benevolence through Tabarru premium. Every participant must pay for Tabarru premium to support one another so that there is sufficient amount to cover unexpected claims among them and to uphold mutual fund as evidence for the sense of mutual co-operation and brotherhood among participants..Keywords: Conventional and Islamic life insurance (Family Takaful); premium; rate making; Tabarru and Mudaraba
Local Structures of Glassy Al under Various Pressures: A Molecular Dynamics Study
Full text linkAl materials are used in the wide range of application, such as sporting goods, engine components, and aerospace parts. The rapid solidification of Al can save energy and production cost. It has been known that the properties of materials highly depend on their atomic structure. However, there is lack of structural investigation of the Al solidification under various pressures. In this research, we carried out molecular dynamics simulation to investigate the pressure effect on the formation of glassy Al from the rapid solidification process. The embedded-atom-method potential is used to describe the interatomic interaction between Al atoms. Our calculated melting point is in reasonable agreement with the experimental result, confirming the capability of the embedded-atom-method potential for use in the high-temperature simulations. From our molecular dynamics simulation of rapid solidification process, it is obvious that the high pressure shrinks the size of the supercell. We also find that the population of local structures, i.e. face-centered cubic, body-centered cubic, and icosahedral cluster, increase at higher pressure except for hexagonal close-packed cluster. The population of hexagonal close-packed local structure in the glassy Al decreases by the increasing of pressure
Ranking Causes of Road Accident Occurrence Using Extended Interval Type-2 Fuzzy TOPSIS
Full text linkOver the past century there has been a dramatic increase in the number of road accidents in Malaysia. Hence, it is necessary to create a decision making method which can consider various preferences and criteria in order to identify the main causes of the accidents. This paper proposes an Interval Type-2 Fuzzy Technique for Order Preference by Similarity to Ideal Solution (IT2FTOPSIS) method which provides a comprehensive valuation from experts. This method is developed based on the aggregation of experts’ opinions on preferred causes of road accidents. The extended IT2FTOPSIS employs a linguistic scales of positive and negative Interval Type-2 Trapezoidal Fuzzy Number (IT2TrFN) and hybrid averaging approach (from an ambiguity and type-reduction methods) to formulate a collective decision environment. Three authorised personnel from three Malaysian Government agencies were interviewed where they were asked to rank the causes. The analysis shows that the linguistic scales of positive and negative Interval Type-2 Trapezoidal Fuzzy Number (IT2TrFN) and hybrid averaging approach are effective in measuring the uncertainties in the interviewees’ responses. Thus this paper concludes that the extended IT2FTOPSIS is more aligned with the users’ decisions compared to the earlier IT2FTOPSIS. Keywords: Multiple criteria decision-making; interval type-2 fuzzy set; IT2FTOPSIS; road accident
Conceptual Design of Natural Composite Grating Platform
Full text linkThere are several types of grating, such as platform, bridge decks and filters. In design process, there are several important terms that have to be prioritised; engineering design, strength to weight ratio, cost, maintainability, reparability etcetera. Advanced materials, such as composite materials offer great strength to weight ratio and high mechanical properties for grating fabrication. Furthermore the reparability and maintenance problems could be solved as it is anti corrosion and the long service life attribute of composite makes it a great design material for replacement of conventional steel or aluminium. Bio composites, such as bamboo and coir fiber yield advantage in terms of less cost and abundance availability compared to commercial unidirectional composite materials, such as glass fiber reinforced polymer (GFRP) and carbon fiber reinforced polymer (CFRP) which is considerably expensive yet possess higher mechanical properties. This papers presents a conceptual design of grating design utilizing bamboo composite as material. Pugh method has been chosen as design criteria selection matrix in finalizing the design of industrial grating for scaffolding (Pugh, 1991).
Prediction of Damage Cost of Bronchitis Due to Haze in Malaysia
Full text linkAwareness of haze pollution and management increased in Southeast Asia since 1990. However, the focus on environmental management is decreasing especially in Malaysia due to the abundant resources and increased development pressure. The total health damage cost because of haze in the country became significantly high due to the long duration of haze events year by year. This paper discusses the health damage caused by bronchitis due to the haze events in Malaysia. The analysis shows positive coefficient of independent variables which indicates the positive relationship between dependent variable and independent variables. Multiple linear regression analysis shows that 45.3% variation in damage cost of bronchitis could be explained by FAI, GDPPC, and CO2. Keywords: Health damage cost; environmental management; haze; Malaysia; prediction
A New Strategy of Handling General Insurance Modelling Using Applied Linear Method
Full text linkThis paper proposes the use of bootstrap, robust and fuzzy multiple linear regressions method in handling general insurance in order to get improved results. The main objective of bootstrapping is to estimate the distribution of an estimator or test statistic by resampling one's data or a model estimated from the data under conditions that hold in a wide variety of econometric applications. In addition, bootstrap also provides approximations to distributions of statistics, coverage probabilities of confidence intervals, and rejection probabilities of hypothesis tests that produce accurate results. In this paper, we emphasize the combining and modelling using bootstrapping, robust and fuzzy regression methodology. The results show that alternative methods produce better results than multiple linear regressions (MLR) model. Keywords: Multiple linear regression; MM estimation; robust regression; bootstrap method; fuzzy regressio