The prediction of wake wash in the towing tank

The wash or ship-generated waves from high speed craft has become a common subject in research and development of marine transportation. Since some time now the wake wash of high speed craft has become a problem in particular on inland or confined waterways. This wake wash has an impact on safety and environment such as bank/shoreline erosion, risk to people on shore and small boats in harbors and changes in the local ecology. This paper describes the results of model test of a high speed patrol, together with theoretical prediction of wake wash

Characterization of hopanes in sediment collected from South China Sea: identification of oil pollution sources

This study investigate the utilities and limitation of pentacyclic triterpane (hopane) including oleanane as oil pollution source identification for sediment samples collected from South China Sea and the applicability of the biomarker approach to sediments and biological samples. Norhopane, 17(α),21(β)-hopane and 17(β), 21(α)-hopane and ∑C31-C 35-homohopane were found to be rich in Middle East crude oil and some of the sediment samples that were being collected in South China Sea. Some other molecular ratios of the biomarker compounds for the sediments such as Tm/Ts and Ts/Tm and n-alkane composition and distribution strongly suggest those 3 out of 27 sediment samples are derived from the Middle East petroleum. The utility of hopane as biomarker to identify the source of tar balls in Strait of Malacca is applicable for oil spill but the data is still limited for Malaysian sediments especially in South China Sea area. The use of oleanane as a biomarker is easily to be found in each sample for this study; however the concentration generally was very low for each sediment sample

Determination of veterinary pharmaceuticals residue in soil and biological materials: a review of current analytical methods

Veterinary pharmaceuticals have been extensively used in animal husbandry for control of disease and growth promoters. These compounds are excreted from animals via urine and faeces, end up in the environment through untreated animal waste disposal. Veterinary pharmaceuticals often exist in the complex solid environmental samples such as manure, slurry, and soil which require extensive extraction, clean-up and analysis method. This review highlights the current analytical methods for the analysis of veterinary pharmaceuticals in complex solid environmental matrices, including soil, animal manures and sediment. The aim of this review is to compare and summarize the performance of each method in terms of recovery, method detection limit (MDL) and method quantification limit (MQL)

Degradation of veterinary antibiotics and hormone during broiler manure composting

The fate of nine veterinary antibiotics and one hormone in broiler manure during 40 days of composting was investigated. Results showed that composting can significantly reduce the concentration of veterinary antibiotics and hormone in broiler manure, making application of the post-compost manure safer for soil application. More than 99% of the nine antibiotics and one hormone involved in this study were removed from the manure during 40 days of composting. The target antibiotics and hormone showed short half-life in broiler manure composting, ranging from 1.3 to 3.8 days. The relationship between the physico-chemical properties of soil, manure and manure compost and its veterinary antibiotic and hormone concentration was statistically evaluated by Pearson correlation matrix. The concentration of veterinary antibiotics and hormone in manure compost was suggested to be affected by physico-chemical properties such as pH, temperature, total organic carbon (TOC), total nitrogen (TN), total phosphorus (TP) and metal contents

Chemometric techniques in distribution, characterisation and source apportionment of polycyclic aromatic hydrocarbons (PAHS) in aquaculture sediments in Malaysia.

This study investigated polycyclic aromatic hydrocarbons (PAHs) pollution in surface sediments within aquaculture areas in Peninsular Malaysia using chemometric techniques, forensics and univariate methods. The samples were analysed using soxhlet extraction, silica gel column clean-up and gas chromatography mass spectrometry. The total PAH concentrations ranged from 20 to 1841 ng/g with a mean of 363 ng/g dw. The application of chemometric techniques enabled clustering and discrimination of the aquaculture sediments into four groups according to the contamination levels. A combination of chemometric and molecular indices was used to identify the sources of PAHs, which could be attributed to vehicle emissions, oil combustion and biomass combustion. Source apportionment using absolute principle component scores–multiple linear regression showed that the main sources of PAHs are vehicle emissions 54%, oil 37% and biomass combustion 9%. Land-based pollution from vehicle emissions is the predominant contributor of PAHs in the aquaculture sediments of Peninsular Malaysia

Super yatch design study for Malaysian sea (Langkawi Island)

Malaysia as a country surrounded by water has a huge economic and geographical potential in the development of super yacht industry in South East Asia. There is lack of super yacht design study specifying to Malaysian marinas and seas. Most of the super yacht operates in Malaysia were built and bought directly from oversea, and chartered by foreign companies. It is hence the purpose of this study to survey on Malaysian sea water, particularly Langkawi Island, to introduce a design methodology in producing a preliminary design of super yacht that suits Langkawi Island, and serves as a guideline for future super yacht design for Malaysian sea in different marinas. Suitable dimensions of super yacht were derived by using dimensional relationship via statistical method. Two types of hull form designs (round bilge and V-bottom hull) were designed using Maxsurf Pro software. Resistance analysis on the two hull forms were carried out using Savitsky Pre-Planing and Compton methods via MaxsurfHullspeed software, and stability performance of the two hull forms was analyze using Hydromax software. VBottom hull form is found to have better resistance performance as compared to round bilge hull form, and both hull forms are found to be in stable conditions and comply with IMO requirements

Wavelets operational methods for fractional differential equations and systems of fractional differential equations

In this thesis, new and effective operational methods based on polynomials and wavelets for the solutions of FDEs and systems of FDEs are developed. In particular we study one of the important polynomial that belongs to the Appell family of polynomials, namely, Genocchi polynomial. This polynomial has certain great advantages based on which an effective and simple operational matrix of derivative was first derived and applied together with collocation method to solve some singular second order differential equations of Emden-Fowler type, a class of generalized Pantograph equations and Delay differential systems. A new operational matrix of fractional order derivative and integration based on this polynomial was also developed and used together with collocation method to solve FDEs, systems of FDEs and fractional order delay differential equations. Error bound for some of the considered problems is also shown and proved. Further, a wavelet bases based on Genocchi polynomials is also constructed, its operational matrix of fractional order derivative is derived and used for the solutions of FDEs and systems of FDEs. A novel approach for obtaining operational matrices of fractional derivative based on Legendre and Chebyshev wavelets is developed, where, the wavelets are first transformed into corresponding shifted polynomials and the transformation matrices are formed and used together with the polynomials operational matrices of fractional derivatives to obtain the wavelets operational matrix. These new operational matrices are used together with spectral Tau and collocation methods to solve FDEs and systems of FDEs

Evaluation of pH and temperature effects on mycoremediation of phenanthrene by Trichoderma sp.

Polycyclic aromatic hydrocarbons (PAHs) are a group of ubiquitous persistent organic contaminants found in the environment most of which are toxic, mutagenic, teratogenic and carcinogenic. For an effective bioremediation of PAHs using micro-organisms, optimum environmental conditions needs to be in place for degradation to occur. The aim of this study was to investigate the effect of physical factors such as pH and temperature on phenanthrene degradation by a sediment fungal isolate Trichoderma sp. SY1 using liquid Mineral Salt Broth (MSB). Both parameters; temperature and pH was observed to significantly affect the strains ability to degrade phenanthrene. Maximum phenanthrene degradations was achieved at a temperature of 35°C and a neutral pH of 7 where degradation efficiencies of 69.5% and 76.8% were achieved respectively with a corresponding high biomass accumulation of 62mg and 48mg dry weight at same temperature and pH points. Lower phenanthrene degradations and fungal growth were observed at lower and higher temperatures. It can be concluded that an optimum pH of 35°C and pH of 7 best supports the strains ability to degrade phenanthrene and should most likely be applied in the microbial PAHs degradation, using this strain