UMT Journal Universiti Malaysia Terengganu
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PARAMETRIC STUDY ON WAVE OVERTOPPING DUE TO WEDGE ANGLE AND FREEBOARD OF WAVECAT WAVE ENERGY CONVERTER
No full textWave energy presents great potential in many coastal regions. This paper deals with WaveCat, a new wave energy converter (WEC) recently patented by the University of Santiago de Compostela. The WaveCat has two hulls, like a catamaran, and it operates according to the overtopping principle. The higher the overtopping amount collected in the reservoir, the higher the energy generated. The wedge angle and freeboard are two important parameters that contribute to a higher overtopping discharge. However, knowledge on the influence that wedge angle and freeboard have on wave overtopping is limited. Hence, this study aims to extend the borders of available knowledge by investigating the influence that two parameters have on wave overtopping discharge through simulation using computational fluid dynamics (CFD). The WEC was designed in the AutoCAD software. Then, the parameters were simulated using CFD. The parameters of wave height and wave period with a specified range are added and the relationship between wedge angle, freeboard and wave overtopping performance of WaveCat were analysed. The validation results showed good agreement between the simulation and physical experiment, with a percentage error of within 20%. The results are useful for further investigation related to optimising WaveCat parameters for selecting the best performance
IMPACT OF COVID-19 ON MALAYSIAN DRY BULK BUSINESS : Article 1
No full textDuring the COVID-19 pandemic, international cross-border restrictions were implemented worldwide. In Malaysia, it was anticipated that the Movement Control Order (MCO) would negatively impact the maritime business as badly as it would on most other economic activities in the country. However, the lockdown in Malaysia, which aimed to “restrict movement”, “reduce contact” and further “isolate the virus”, did not impact maritime business as much as other industries. In fact, the maritime waterways remained the main artery to transport essential goods nationwide during the pandemic. This paper analyses the impact of the pandemic on the maritime business in Malaysia by studying the commercial and technical aspects. Primarily, the paper focuses on dry bulk trade, container business, port infrastructure, and parties involved in the maritime supply chains. It finds that the impact of the pandemic was minimal, and certainly not as prominent as anticipated; in fact, the Baltic Dry index touched a new high during this period. This paper uses secondary data and draws on the analyses of the Baltic Dry Index, Platts Report by S&P, and Review of Maritime Transport by the United Nations Conference on Trade and Development. The paper is divided into three sections: The changes in selected maritime sectors before and during the pandemic, the factors affecting dry bulk market growth in Malaysia, and the lessons learnt and corresponding recommendations to improve Malaysian maritime business post-pandemic
MANEUVERING PERFORMANCE OF TUGBOAT USING COMPUTATIONAL FLUID DYNAMICS (CFD) APPROACH
No full textConcerning on navigational safety of a ship, comprehensive investigation of manoeuvrability of the ship is prominently required. The turning instability due to improper speed and magnitude of the rudder angle is vulnerable to serious accidents such as collision especially in the confined waters. This paper presents a computational fluid dynamic analyses on manoeuvrability performance of a tug in calm water. Here, the characteristics of the turning ability and zig-zag characteristics of the tug has been assessed due to effect of the various angles of twin-rudder and turning speeds. The results revealed that the increase of rudder’s angle resulted in subsequent reduction of her advance diameter from 144 m, 108 m, 96 m to 92 m. While for zig zag manoeuvre, the first overshoot angle is 0.6° and 1.08° for 10°/10° and 20°/20° rudder’s angle respectively. The first overshoot and second overshoot angle are within the IMO criteria which is below 20° and 25°. However, the increase of turning speed from 7 knots to 9 knots has been proportional with the increase of the turning diameter (advance diameter) from 70 m to 105.2 m. Basically, the turning performances of the tug manoeuvring with the turning speed of 7 to 9 knots incorporated with rudder’s angle 20°, 25°, 30° and 35° have been complied with IMO manoeuvring standards. This preliminary analysis contributes very valuable findings at early ship design stage to provide a safety of the navigational guidance for turning ability of the tug
ASSESSMENT OF HEAVY METAL CONCENTRATION IN MARINE SEDIMENTS IN TERENGGANU WATERS
No full textThe distribution of heavy metals (Cu, Zn, Cd, Pb) in surface sediments was examined in waters off the coast of Marang, Terengganu. A total of 20 samples were collected using Ponar grab and analysed by inductively coupled plasma-mass spectrometer after closed digestion with acid. The sediments were filtered using a dry sieving method to determine their particle size. The spatial distribution maps on the concentration of selected metals were drawn using the ArcGIS software. Results showed that the average concentration of Cu, Zn, Cd, and Pb were 2.33±0.38 μg/g dry weight, 28.4±3.78 μg/g dry weight, 0.09±0.01 μg/g dry weight and 8.35±1.48 μg/g dry weight, respectively. The level of pollution was also evaluated using the Index of Geoaccumulation (Igeo) and Pollution Load Index (PLI). All Igeo and PLI values obtained were low, which indicated low or no pollution. Meanwhile, the sediment mean size ranged between -0.77Ø and 3.18Ø, which characterised a sandy type of sediment. Correlation analysis showed a positive correlation between the heavy metals and sediment size. The results indicated that there was a common source of heavy metal pollution in the study area, possibly from shipping activities. Overall, there was no significant heavy metal pollution in the waters off Marang. This finding is important as the data could be used to evaluate the risk of metal contamination and the impact of anthropogenic activities on the marine environment
RISK ASSESSMENT AND MITIGATION FOR BETTER SAFETY: CASE STUDY OF KEMAMAN PORT
No full textThe increase in awareness and responsibilities among stakeholders in a port environment has made safety evaluation an operational priority. Operating a port is a high-risk activity with underlying potential for accidents and loss of lives, besides causing massive property and environmental damage. Kemaman Port has multiple operations and handles volatile chemicals that may lead to disaster if an accident were to occur due to negligence. Therefore, the safety tools at the port have to suit a terminal specialized in handling liquid chemicals. To determine risk level at the port, assessment may be conducted using the hazard identification method (HAZID) to determine the hazards and risk matrix. The “As low as reasonably practicable” (ALARP) principle should be adhered to in determining which risk is tolerable or intolerable. In this study, the hazard and risk data at Kemaman Port were obtained through literature review and engagements with experts. As a result, eight main hazards were identified and the risk matrix was used to find the highest frequency and consequences of the hazards, besides the risk probability during operations. The overall results may demonstrate a significant improvement to the safety of port operations
KAJIAN PENCEMARAN AIR TERHADAP KOMUNITI ORANG ASLI DI TASIK CHINI, PAHANG
No full textPencemaran air di Tasik Chini, Pahang kian meruncing akibat pembangunan sekitar yang tidak terkawal menyebabkan kemusnahan rantaian makanan sekaligus mengancam kelangsungan hidup komuniti asli. Justeru, kajian telah dijalankan bagi mengenal pasti faktor, impak dan keberkesanan strategi dengan menggunapakai Teori Pengambilalihan. Selain itu, kajian ini dipilih untuk memenuhi kelompangan kajian terdahulu yang lebih menekankan kepentingan pengekalan biodiversiti flora dan fauna berbanding kajian terhadap kehidupan komuniti setempat. Maka, kajian deskritif tinjauan telah digunakan melalui kaedah pemerhatian, temu bual mendalam bersama empat orang informan, dianalisis secara transkripsi, triangulasi dan analisis kandungan. Dapatan kajian menunjukkan faktor pencemaran air berpunca daripada pembinaan empangan air, projek pembangunan, aktiviti pembalakan, aktiviti perlombongan dan hakisan tanih. Sementara, pertanian komersial juga menjejaskan kegunaan domestik, hidupan akuatik terganggu, perubahan sifat air, kehilangan sumber pendapatan, dan tahap kesihatan terjejas. Oleh itu, cadangan memperluaskan program advokasi seperti pengawalan pembuangan sampah sarap, pematuhan Penilaian Impak Alam Sekitar (EIA), penglibatan pihak awam dan swasta, pemantauan kesihatan, kesedaran awam, dan melakukan penyelidikan lanjutan. Kajian mendapati dua buah syarikat China mengeksport bijih besi yang diperoleh sekitar Tasik Chini menggunakan permit AP (Eksport dan Import) dari negeri lain, bukannya Pahang. Meskipun syarikat tersebut tidak mempunyai lesen melombong tetapi mereka mempunyai segala kelengkapan alatan memproses dan menjalankan operasinya hingga kini. Diharapkan isu pencemaran air di Tasik Chini dapat dipulihkan demi menjamin kelestarian sejagat
DEVELOPMENT OF MARINE ENGINE PERFORMANCE PREDICTION MODEL THROUGH NEURAL NETWORK APPROACH
No full textThe prediction and control of marine diesel engine performance and emission rates is not an easy task in real time. Comprehensive engine performance testing for entire operating conditions is extremely costly and time consuming. Therefore, the option of using a computer model can be used to determine those parameters. This work is concerned with the modeling of artificial neural networks in predicting the performance parameters of marine diesel engines such as torque, power, fuel consumption, efficiency and exhaust emission gases. Input data were obtained from engine tests in the laboratory operated with palm biodiesel and running at various speeds and loads. The predicted results have been validated by comparing the output values of the model with the experimental data. The results show that the prediction model using neural network gives good agreement to the experimental results which yield higher correlation coefficient of 0.98194 and lower mean square error of 0.0026809. This study proves that a trained neural network model is capable to determine the performance of marine diesel engines in the accepted range
EXCHANGE RATE FORECASTING USING FUZZY TIME SERIES-MARKOV CHAIN
No full textExchange rate forecasting plays an important role in financial management. However, it is a complex process with high nonlinearity and data irregularity. Moreover, the forecasting of exchange rate is highly involved with imprecise and uncertain data. Analysis of forecasting models which corresponds to the exchange rate has always experienced fluctuations. Therefore, exchange rate forecasting becomes a challenging task in finance. Several studies have shown that stand-alone forecasting models such as time series, fuzzy time series, and Markov chain have their own drawbacks and are not successful enough in forecasting accurately. In this study, we propose a hybrid model of fuzzy time series-Markov chain to forecast the future exchange rate. Fuzzy time series-Markov chain is a combination of the classic fuzzy time series model with Markov chain model used to analyse a set of time series data. The main motivation for this study is to improve the accuracy in exchange rate forecasting. The selected currencies are Malaysian Ringgit (MYR) and Singapore Dollar (SGD). The proposed model was then evaluated by the Mean Absolute Percentage Error (MAPE) performance metric to test the robustness of the model. Lastly, a comparison between the proposed model and fuzzy time series model was conducted with respect to the MAPE. The results showed that the MAPE value for fuzzy time series-Markov chain was 0.9895% which fell under the criterion of highly accurate forecasting. Meanwhile, the MAPE value for fuzzy time series was 3.4306%. Thus, the forecasting performance of the proposed model was better than the fuzzy time series model. This study reveals the potential benefits of the proposed model as a highly accurate forecasting model
ASSESSMENT OF HEAVY METALS DISTRIBUTION IN THE SURFACE SEDIMENT OF KEMAMAN RIVER, TERENGGANU
No full textIn the present day, rivers are used by people as water sources for their daily agricultural, industrial and cleaning purposes. However, industrial development and human activities are rapidly impacting the river’s catchment area, which can cause contamination of heavy metals in the water and sediment. The Kemaman River is one of the rivers that may be affected by these pollutants. Thus, the concentration of selected heavy metals such as copper (Cu), zinc (Zn), cadmium (Cd), lead (Pb), arsenic (As) and mercury (Hg), plus the pollution status was determined in the surface sediments of the Kemaman River. A total of 46 sediment samples were collected along the river. Teflon Bomb digestion method with 2.0mL of mixed acid (concentrated nitric acid, hydrochloric acid and hydrofluoric acid with ratio 3:3:1) was performed followed by analyzation using Inductively Coupled Plasma Mass Spectrometry (ICPMS). The status of heavy metals contamination in the study area was determined by the index of geoaccumulation (Igeo) and pollution load index (PLI). The calculated Igeo value suggested that the sediments in the Kemaman River were categorized under unpolluted to polluted category. However, the calculated PLI suggested that the study area is polluted with heavy metals. The correlation of the sediment mean grain size and the selected heavy metals was strongly correlated. The concentration of metals increased with the rising mean grain size, which suggests their association with the fine fraction of the sediment
EFFECT OF SILICON NUTRIENT AND SALINITY (ABIOTIC STRESS) ON TOMATO PLANT (Solanum lycopersicum)
No full textTomato (Solanum lycopersicum) imports have increased in Malaysia due to high demand. One of the constraints to local production is excessive salinity in soils that leads to toxicity in crops, reduction in soil fertility and reduction of availability of water to tomato plant that is known to be sensitive to high salinity. Nevertheless, silicon nutrient proven could protect plants from abiotic stress. Therefore, the objectives of this study were to determine the plant growth of tomato plant treated with silicon (Si) under salinity stress and to observe the physical changes of stems. A total of ten treatments (T1 – T10) were applied with different concentrations of silicon: 0.5% Si (v/v), 1.5% Si (v/v), 2.5% Si (v/v), potassium silicate as positive control whereas negative control (only water and 0.5% NaCl) and a mixture of equal volumes of the silicon and potassium silicate treatments with 0.5% NaCl. The treatments were applied once a week (40 ml for each plant pot). Throughout this study, plant growth data was collected (plant height, diameter of stems, time of anthesis, number of fruits, and chlorophyll content). Results showed that with 0.5% Si (v/v) and 1.5% Si (v/v) (with 0.5% NaCl), the tomato plants grow well especially in plant height, number of leaves and chlorophyll contents. Furthermore, cross section of stems showed a significant difference (p<0.05) in stem diameter among treated plants [2.5% potassium silicate (T4), 0.5% Si (v/v) + 0.5% NaCl (T6) and 2.5% potassium silicate + 0.5% NaCl (T9)] and control (0.5% NaCl). However, the largest vascular bundle width was recorded in plants treated with 1.5% Si (v/v). This study has proven that tomato plants could uptake silicon and improve the plant growth under salinity stress conditions and giving potential for Si as biostimulant to other Solanaceae family (potato, pepper and eggplant)