30 research outputs found

    A New Method for Cargo-Passenger Vessel Hydrostatic Parameters Analysis

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     In this study, software that can analyze ship hydrostatics parameters using Java programming language is developed. Ship hydrostatic parameters are properties of the immersed portion of the ship in water. The analyses of ship hydrostatic parameters are done by employing computer software, but the cost of acquiring the license of such expert software is expensive. Owing to this fact, this research was carried out to meet the need of analyzing ship hydrostatics parameters for both academic and industrial applications at marginal expense. Java programming language was adopted for this research because of its outstanding features such as internet security, portability, variety of integrated development environments (IDEs), platform independent and free to download on internet. The mathematical approximation or integration method as a technique for formulating ship hydrostatics parameters was adopted for this research. This is because it has the ability to make use of computer technology and it can be used to obtain the area of a ship and other hydrostatics parameters. The results produced in this research are reasonable and acceptable as evidenced from the comparison analysis with existing results of offsets values of a cargo-passenger vessel obtained from SNAME.

    Assessment of the Performance Status of a Wharf

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    This paper suggests Fuzzy-logic-rule base method to assess the performance status of a wharf in order to classify it. The method proposed is predicated upon its ability to analyse processes and operations based on subjective judgement with little or no statistical data available. The study also shows that fuzzy-logic rule base is a veritable tool to qualitatively and quantitatively assess the status of a wharf offering ferry service. Using the model developed in this study, the performance status of Yenagoa wharf has been determined to be orange, having a (WPS) overall of 4.8. The status of the wharf has been in good agreement with the perception of stakeholders that the Yenagoa wharf needs restructuring to curb the frequent crisis occurring among stakeholders. The model also indicated those areas of the wharf’s operations needing attention. The study indicates that even though major components that determine the quality and profitability of the wharf’s ferry service are high in value, the overall status of the wharf may not be necessarily high. As such, the study method can be used to control the growing ill-feeling between boat operators and passengers while harmonizing all stakeholders (operators, passengers, and regulators etc) to work together to improve the status of the wharf

    Development of a New Air Compressor System for Ship Operation

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    An optimal operation of compressors used onboard vessels for various purposes is very important. In this study, the drawbacks of conventional air compressors are addressed. Interruption of the operations by unpredictable electrical power blackout and corrosion are the key drawbacks. The corrosion occurs due to a manual drain, which depletes the life of the air tank, thereby causing damages to the compressors. To address this challenge, the need for modification of conventional air compressors is imperative. Hence, this study entails the design and fabrication of an air compressor system with rechargeable characteristics, well equipped with an automatic drain sensor and pressure switch, to obtain optimal system efficiency and reliability. From the obtained results of the test and performance of the compressor, it is obvious that it is efficient and reliable for onboard ship operations

    Advanced risk and maintenance modelling in LNG carrier operations

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    High demand of Liquefied Natural Gas (LNG) in recent time requires LNG carriers in more frequent operations in order to meet customers' needs. To ensure that the LNG carriers are always reliable in service, it has become necessary to adopt various advanced modelling techniques such as Genetic Algorithm (GA), fuzzy logic and Evidential Reasoning (ER) for risk/safety assessment and maintenance modelling of LNG carrier operations. These advanced computational techniques can help to overcome challenges posed by uncertainties associated with the LNG carrier operations. Their usefulness is demonstrated using case studies in this research. Firstly, two major hazards of LNG carrier operations such as "failure of LNG containment system" and "LNG spill from transfer arm" are identified and estimated as high risk ones using a risk matrix technique and expert judgement. The causes (failure modeslbasic events) of these high risk hazards are analysed using a Fault Tree Analysis (FTA). The failure logics of their failure modes are established and Boolean algebra is applied to facilitate the evaluation of the failure probabilities and frequencies. Secondly, a GA model is developed to improve the safety levels of the LNG containment system and transfer arm, to minimise their maintenance costs and to realise optimal resource management. The GA is used to optimise a risk model that is developed with exponential distribution and parameters such as failure frequencies, unit costs of maintenance and new maintenance costs of the LNG containment system and transfer arm. Thirdly, the uncertainties of some parameters in the GA model such as unit costs of maintenance are subdued using the strength of Fuzzy Rule Base (FRB) in combination with GA. 125 fuzzy rules of LNG carrier system maintenance cost are developed, which makes it possible to facilitate the evaluation of maintenance cost in any specific LNG risk-based operation. The outcomes of unit costs of maintenance are used in the GA based risk model to update the optimal management of maintenance cost. Finally, the uncertainties of failure modes of the LNG containment system and transfer arm are investigated and treated based on the Formal Safety Assessment (FSA) principle using a Fuzzy ER (FER) approach. The fuzzy logic is used to estimate the safety/risk levels of those failure modes while the ER is used to synthesise them to facilitate the estimation of safety/risk levels of the top events. Risk Control Options (RCOs) are developed to manage high level risks. The costs for each of the RCOs are estimated and synthesised using ER, which facilitated the investigation of the best RCOs in risk-based decision making. There is no doubt that the methodologies proposed possess significant potential for use in improving safety and maintenance of LNG carrier operations based on the verifications of their corresponding test cases. Accordingly, the developed models can be integrated to formulate a platform to facilitate risk assessment and maintenance management of LNG carrier systems in situations where traditional techniques cannot be applied with confidence

    Comparative Screening of the Nutritive Composition and Serum Nutrient Levels of Rats Weaned with Rice (Oryza spp) - Beniseed (Sesame indicum) Flour Blends

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    Weaning foods should complement the nourishment the baby receives from milk. This study was carried out to evaluate the nutritional value of Rice-Beniseed (R-B) flour-blends in rats’ pups. The objective of the study was to determine the Nutritive value of Rice-Beniseed flour blends of rats’ pups weaned with different ratios of the flour-blends. First, mature female and male rats in the ratio of 2:1 were mated to produce pups used in the analyses. The pups were randomly distributed into five groups of five rats and were fed with the experimental (Rice-Beniseed) blends. Group 1 was fed with a standard weaning meal, groups 2, 3, 4 and 5 were fed ad lib with Rice-Beniseed blends (after proximate analysis for nutritive content) in the ratio of 30:70, 50:50, 60:40 and 70:30 respectively. All treatments lasted for 21 days, after which their blood was collected for haematological and biochemical analyses. The results showed carbohydrate (71.76 %) and moisture content (14.75 %) of rice to be higher than beniseed with values of 18.74 and 8.24 % respectively. The crude proteins (23.19 %), crude fibre (11.47 %) and fats (36.40%) content in beniseed was more than doubled compared to that in rice with 9.38 %, 1.339 % and 2.41 % for crude protein, crude fibre, and fats contents respectively. Percentage weight change in pups was highest (26.31 ± 1.03%) and least (8.69 ± 2,32%) in the 50:50 and 60:40 rice-beniseed groups on day 7. Percentage weight change of pups on day 14 showed that groups fed with 70:30 and 50:50 ratios with the highest (37.24 ± 0.47%) and least (6.16 ± 1.14%) weight gain respectively. Hence, 70:30 (Rice-Beniseed blend) meal produced the best growth index (weight increase) and was potentially viable for the formulation of infant weaning formula amidst appreciable performance of all other ratios

    THE DISINTEGRATION OF YUGOSLAVIA: A LESSON FOR NIGERIA

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    The prediction by some experts within the United States National Intelligence Council in a document entitled “Mapping Sub-Saharan Africa’s Future” predicting outright collapse of Nigeria as a nation state cannot be wished away. The study examined the factors that precipitated the disintegration of Yugoslavia and juxtaposed them with the past and present religious and socio-political state of Nigeria. The paper maintained that virtually all the factors that led to the break-up of Yugoslavia abound in Nigeria. These factors include deep seated inter-ethnic rivalries, religious intolerance, dearth of national integration, internal colonialism and deficiencies in Nigeria’s federal structure. The real danger is not even the possibility of the break-up of Nigeria into new states; this would not necessarily be a problem, but the collapse of Nigeria into utter chaos and manslaughter. The study recommended true fiscal federalism, constitutionalism, respect for sectionalism, national integration and the implementation of the resolutions of the 2014 National Conference as measures to checkmate the disintegration of Nigeria.  Article visualizations

    Ship Propeller Performance Prediction under Cavitation

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    In this study, numerically prediction of the screw propeller design that can overcome cavitation is conducted. The research presents a simplified regression model for the analysis of the geometric area ratio, pitch ratio and open water efficiency of propeller, with the aim of revealing quantitatively the effect of cavitation on propeller open water efficiency. The case study takes into consideration factors that can enhance the performance of a propeller. Area of the propeller disc, propeller pitch ratio, diameter of the propeller, delivered power, thrust coefficient, torque is used as inputs into the model, in prediction of performance for cavitated and non-cavitated propellers. Sensitive analysis is carried out by percentage increase and reduction of the blade area ratio, so as to know the effects on the propeller performance. It is revealed that for every 1% increase in the expanded blade areas, the open water efficiency decreases at 0.12% and 0.15% for the non-cavitated and cavitated propellers respectively. This indicates a performance reduction by a cavitation factor of 0.03. The study further shows that at 7.5% reduction in the expanded blade area ratio, the propeller performance in terms of open water efficiency, increases by 1.85%. The analysis exposed an appropriate and accurate operating envelope for optimal screw propeller performance, thus revealing a way of minimizing cavitation effect
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