In this study, the effects of the additive on engine performance and emissions were investigated by adding cerium oxide (CeO2) nanoparticles (NPs) into diesel fuel. The use of CeO2 NPs as an additive increased the lower calorific value (LHV) of the fuel while decreasing its viscosity and density. As a result of the experiments, an increase of 8.99% in engine torque was obtained in DCe100 fuel which 100 ppm CeO2 NPs were added compared to diesel (D0) fuel. The increase in the LHV had a positive effect on the specific fuel consumption. The use of CeO2 NPs resulted in an increase in brake thermal efficiency (BTE) due to the increased ending temperature of combustion. A 5.44% increase was obtained in DCe100 fuel compared to D0 fuel in terms of BTE. With an increase in the amount of CeO2, carbon dioxide (CO), hydrocarbon (HC), and smoke emissions were reduced. Compared to D0 fuel, the lowest values were obtained with the DCe100 fuel. CO emissions were reduced by 18.27%, HC emissions by 30.12%, and soot emissions by 21.63%. However, nitrogen oxides (NOX) emissions increased with rising CeO2 amount and in-cylinder temperature. The highest NOX value in DCe100 fuel was obtained with an increase of 6.65% compared to D0 fuel.

Inland waterways in India have shown positive growth over the last 10 years. The mode of transport is very promising, yet desired volumes are yet to be achieved. In 2018, India started its first domestic container shipping and the first export of container shipping through inland waterways in 2020. This research work expedites the identification of various prominent factors using the fuzzy analytic hierarchy process method. Four major factors were considered based on feedback from experts, and using the said method, factors and subfactors were ranked globally. Among the four factors we considered, infrastructure factors were found as the most critical factor, followed by economic factors, geographical factors, and, lastly, regulatory factors. Moreover, as per the weights obtained for the subfactors, inadequate river depth of rivers, container inventory, and repositioning emerged as significant factors that need to be addressed. Finally, this research paper puts forward steps necessary for boosting the growth of container shipping through inland waterways.

In recent years, energy and fuel efficiencies have been considered in scientific studies. These parameters become extremely important in maritime, especially for fishing vessel activities. In this study, an innovative approach is proposed to reduce the fuel consumed by fishing vessels and carbon emissions to the environment during the fish exploration process. Key elements of the proposed approach are autonomous underwater vehicles (AUVs) and the application of swarm intelligence. With this approach, which can be considered a pioneer in maritime, the AUVs released from the fishing vessel find the school through the swarm intelligence behavior of Grey Wolves. In this article, the method is modeled as a simulation, and its applicability in the future is also discussed. In the present studies, the conventional fish search method and the proposed method were modeled, and the results were examined. When the obtained results are examined, it is seen that the proposed method increases the successful voyage rate by 2.94 times compared to the conventional method, while the distance covered in the exploration activity decreases by 8.61 times. The results demonstrated that the proposed innovative approach is an energy-efficient, cost-effective, and environmentally friendly solution that is also applicable and usable in the future.

The current research is focused on determining the optimum true wind angle (TWA or β TW ). A model is developed to calculate the wind angle at which a sailboat’s optimum performance can be achieved. First, the equations for the hull speed, velocity made good (VMG), and the heel angle are determined through the regression analysis by using the data produced by the velocity prediction program analysis. The equations are written for true wind velocities ( V TW ), with the independent variable being TWA. Later, a multiobjective optimization model is developed, and the wind angles providing the maximum benefit at the respective wind velocities are determined. The goal of the model is to maximize the hull speed and VMG while minimizing the heel angle. The simulated annealing algorithm is employed. Consequently, TWAs providing the optimum performance of a specific sailboat at various wind velocities are calculated.

To determine the market value of a ship management company, apart from its book value, it is necessary to also know its intellectual capital. The impact of this type of capital is evident, especially for ship management companies that are service-based. If these businesses follow the intellectual capital level and managers determine the necessary strategies based on this, these companies, which compete internationally beyond ensuring the continuity of their businesses, can stay one step ahead of their competitors. The purpose of this article is to provide an analytical perspective for ship management companies to evaluate their intellectual capital. In this context, the study adopts the analytical hierarchy process in the environment of fuzzy sets to increase sensitivity. Based on the analysis results, the most important intellectual capital elements for ship management companies are “human capital” as compared to “structural capital” and “relational capital” elements. As the key performance indicators applied for evaluation may differ according to enterprises, group performance indicators to be evaluated in the measurement of the elements were determined. The indicators related to human capital were more weighted than the others. This study guides not only the evaluation of the intellectual capital of ship management companies but also the determination of new strategies by managers for the development and valuation of companies.

The goal of this work is to investigate fresh and used marine engine oil by high-resolution 1H nuclear magnetic resonance (NMR) as well as by NMR relaxometry with Laplace transform inversion. The largest decrease in the molar content of CH3 groups was observed in used 10W40 oil, from 37.7% to 27.3%, and the largest increase in the content of CH groups was observed in 15W40 engine oil, from 8.8% to 11.5%. The inversion method based on standard deviation minimization and regularization (RILT) was used to obtain the distribution of relaxation times. It is demonstrated that the bimodal distributions of the longitudinal relaxation times practically differ very little between fresh and used oils. T2 relaxation times for the used 10W40 oil (21 ms and 63 ms) shift to shorter values in the bimodal distribution when compared to fresh oil (25 ms and 89 ms). The T2 relaxation times for the used M-4015 oil increased from 14 ms and 42 ms to 19 ms and 60 ms, respectively. This indicates a change in the mobility of the functional groups of macromolecules caused by a change in the viscosity of the used oil. It is proposed to use the NMR method of proton relaxometry and the distributions of relaxation times to diagnose marine engines using used motor oil.

The Turkish Straits are critical waterways connecting the Mediterranean and the Black Sea. About 38,552 and 43,343 ships pass through the Strait of Istanbul and Strait of Canakkale annually, respectively, and their emissions into the air pose a threat to the regional and global environment, as well as to the people of the region. Herein, the effects of the declaration of the Sea of Marmara as an emission control area and the use of alternative fuels by ships on emission formation were examined. For this purpose, the data of the ships passing through the Turkish Straits were obtained, the engine powers were calculated based on the gross registered tonnage values of these ships, and the emission values were reached. Declaring the Sea of Marmara as an emission control area provides an 80% and 76% reduction in sulfur and nitrogen oxides, respectively. Carbon emissions remained the same. The use of liquefied natural gas dramatically reduces carbon emissions. Alternative fuels, especially liquefied natural gas, effectively reduce sulfur oxide emissions. Despite these positive effects, there seem to be many years ahead of the widespread use of alternative fuels due to the lack of technical and economic infrastructure. Thus, the declaration of the Sea of Marmara as an emission control area will positively affect both the population in the region and the region’s environment.