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With the continuous promotion of energy saving and emission reduction policies, the development of highly efficient and low emission green ships is the priority for the industry. Hybrid (or all- electric) ships that consider multiple forms of energy storage and clean energy have the potential of energy saving which have been widely studied. Energy management as a key technology for coordinating the efficient working of all energy sources on board ships has become a focus of research. Firstly, this paper visualises and analyses the literature in this field by CiteSpace to clarify the development trend of ship energy management. The research hotspots in energy management are summarised by keywords and clustering: optimal design of ship power (propulsion) systems, control of microgrids, efficient energy management strategies (EMS) and its test verification. Subsequently, the structure or classification, research focus and key technologies of these four contents are analysed in detail. Finally, the persisting problems were summarised, and corresponding solutions were proposed. The results show that ship energy management is a systematic problem, which needs to be comprehensively considered from multiple perspectives such as design selection, energy transmission, operation management, and performance evaluation. Thereinto, power quality control, multi-objective collaborative optimisation, algorithm fusion and test verification are key to the research.

Speed optimisation is an important energy efficiency practice, which can bring good economic and environmental benefits. The methodology of the speed optimisation and dynamic programming of ships are firstly investigated. With the total fuel consumption as the objective function and main engine speed as the decision variable, a novel multi-stage speed optimisation model of ship is then developed based on dynamic programming algorithm. A Yangtze river ship is selected as a case study, the actual operational data are acquired through sensors installed onboard the ship. Using the operational data, regression analysis is applied to establish the relationship models of ship fuel consumption and speed in relative to main engine speed. Finally, simulating calculation and comparative analyses are carried out. The results indicate that the velocity and direction of water flow is a key factor affecting the speed optimisation of ships in the Yangtze river; the proposed multi-stage decision making method is effective in the speed optimisation for ship with a long-distance and changing-environment voyage. This study can provide methodological support for ship navigational optimisation.

The ship fuel consumption (SFC) model is crucial for research on ship energy efficiency simulation, optimisation, and carbon emission prediction. In this study, the bibliometric tool CiteSpace was used to conduct a literature review on SFC models. Based on the review, it was concluded that the current SFC models can be classified into three types: white, black, and grey boxes. Considering the different types of SFC models, the advantages and disadvantages, accuracy improvement methods, and verification methods were analysed. Furthermore, the influencing factors of the SFC models were investigated. Based on the top-down and bottom-up modelling methods, appropriate applications of the SFC models were analysed. Furthermore, the SFC models suitable for different operation stages of ships were classified based on the degree of data availability. Finally, the persisting problems in SFC models were summarised, and corresponding solutions were proposed. In addition, future research directions for SFC models were also proposed. This study can serve as a reference for research on ship energy efficiency improvement and carbon emission forecasting.

Exhaust gases from marine engines are one of the major causes of marine environmental pollution. Although the researches into ship emissions are more focused on ocean-going vessels, emissions from short-sea and inland navigation also contribute to the global amount of pollutant emissions produced by combustion of fuel oil. While this share is small, short sea and inland ships usually operate in highly populated areas and consequently affect both human health and environment. In order to evaluate the environmental impact of river cruise ship that occasionally operates in Croatian inland waterways, its life cycle assessment (LCA) has been performed. Two different power system designs were investigated, i.e. lithium-ion battery- powered ship and diesel engine-powered ship. The analyses were performed by means of general LCA software GREET 2018, The analysis showed that diesel engine-powered ship emits 46.63 kg CO2- eq/nm, versus battery-powered ship with 20.39 kg CO2-eq/nm.

Energy efficiency management is becoming increasingly important in the trend towards decarbonisation and intelligentisation of future ships. Establishing a verified energy efficiency model is essen...

This study puts forward an optimal speed decision-making method for a coastal bulk carrier as an important energy efficiency practice. Firstly, the ship resistance model is established considering the impact of multiple environmental factors, such as wind, waves and shallow water; on this basis, according to ship–engine–propeller interaction mechanism, the ship energy consumption model is established. Then, the ship speed optimisation model is established and the multi-objective genetic algorithm is applied to obtain the most fuel-efficient speed set. Finally, a coastal bulk carrier is selected for a case study to implement the proposed method, and the fuel saving as well as the economic and environmental benefits are analysed. The results indicate that the proposed speed optimisation method can calculate the optimal speed for each leg of shipping line and that the total fuel consumption of the target ship can be reduced by 8.47% through increasing the sailing time and expanding the low-load operational range of the main engine. This study can help the crew members to improve the energy efficiency management of ships.

Emissions reduction targets are pushing the shipping industry towards cleaner and more energy-efficient solutions. One option proposed is to replace conventional marine fuels with cleaner fuels. This is particularly important for vessels engaged in short-sea shipping and inland waterway transportation because their exhaust gases more negatively affect the local population than long-distance ships do. Hence the aim of this study is to undertake a technical, environmental and economic analysis of alternative fuels to reduce the environmental footprint and lifetime costs of inland waterway transportation. The analysis will focus on Croatia whose existing outdated inland waterway fleet needs to meet the goals of the Low-Carbon Development Strategy of the Republic of Croatia. In the study, a life-cycle analysis and life-cycle cost assessment of different alternative fuels will be performed taking into account the operating profiles and technical characteristics of vessels working in Croatia. The potential effects of a carbon tax are also examined in a case study considering carbon emissions reduction targets in Croatia by 2030. The electrification of ships is highlighted as the most environmentally friendly option for each considered ship, reaching a carbon emission reduction of up to 51%, while the most cost-effective option varies for each ship.

The reduction of emissions generated by internal combustion engines represents one of the most important research topics in the marine sector. This especially refers to carbon dioxide (CO2) which is a major greenhouse gas. This paper deals with the viability of alternative fuels to reduce CO2 emissions in the Croatian short-sea shipping sector over a ship lifetime. The aim of the study is to identify appropriate alternatives to diesel-powered options, taking account of environmental and economic criteria. Besides diesel, which is currently the main marine fuel in Croatia, an analysis was conducted of electricity, methanol, dimethyl ether, natural gas, hydrogen and biodiesel, and the results are illustrated on three different Croatian ro-ro passenger ships, operating on short, moderate and relatively long routes, respectively. Life-Cycle Assessment (LCA) indicated the most environmentally friendly power system configuration with alternative fuel. The investigation from an economical point of view was performed by Life-Cycle Cost Assessment (LCCA) which also considered potential carbon allowance scenarios. The results highlighted an electricity-powered ship as the most ecological as well as the most cost-effective option among those that are investigated, taking account of the real Croatian electricity mix that includes 46% of renewable sources.

Developing a green, intelligent, and efficient power system is an important way for the shipping industry to respond to increasingly stringent emission regulations, and to achieve improvements in energy conservation and efficiency. In this study, a two-phase energy efficiency optimisation method is proposed for reducing energy consumption. The method comprises a combination of speed optimisation and energy management. On the demand side, the minimum accumulated power consumption required by the propeller is set as the objective function for the speed optimisation model, whereas on the supply side, the lowest cost of energy consumed by the hybrid power system is set as the objective function for the energy management model. An inland parallel hybrid electric powered bulk carrier is selected for a case study of the two-phase energy efficiency optimisation method. The optimisation results are compared with the energy consumption data of a bulk carrier under normal working conditions. The results show that the proposed method can reduce the energy consumption by 2.60% and 9.86% in the westbound and eastbound voyages, respectively. Accordingly, this study can provide methodological support for inland hybrid-powered ships aiming to achieve intelligent energy efficiency management.

In the context of harsh emission control and ecological environment protection, the shipping industry is transforming and upgrading towards greening, decarbonisation, and electrification. The energy and power types of inland ships are becoming increasingly diversified. It is urgently important to investigate strategies for decarbonising inland ship power systems. First, the development status of inland shipping in China is introduced with respect to shipping resources, existing problems, and driving factors of green development. Then, the power requirements of inland ships and the characteristics of new power systems are analysed, and on this basis, alternative solutions for inland ship power systems are proposed. Two case studies are carried out, focussed on canal and Yangtze River ships using battery power and hybrid power, respectively. Moreover, environmental and economic impacts during the life cycle of the two typical alternative solutions are assessed. Finally, an uncertainty analysis method is adopted to assess the reliability of the life cycle assessment and life cycle cost assessment results. The results indicate that compared with traditional diesel power, battery power and hybrid power have lower lifetime CO2 emissions and costs, under four considered carbon credit scenarios. The proposed alternative solutions and assessment methods are of significance for guiding the low-carbon development of inland ship power.

This paper described a pulse discharge hypocenter system, which can be used to carry out arc pulse discharge and corona discharge. At the same time, an experimental platform was set up, which consists of a pulse hypocenter system, a voltage–current measurement unit, a digital oscilloscope and a seismic detection system. On this basis, the experimental study of arc discharge and corona discharge was carried out at different voltages, different electrode gaps, and different excitation positions. In detail, the curves of the voltage and current of multiple discharges were put in the same axis to show by using the data input function of the Origin Pro 9.0 software, so as to contrast and analysis the data. In addition, at the same time of each discharge, 50 detectors inserted into the different ground received real-timely seismic waves coming from the source. Then, the detected seismic-wave intensities were recorded by the central recording system. Through the analysis and processing, the characteristics of corona discharge and arc discharge were summarized and compared, which can provide a useful reference for the design of pulse discharge hypocenter.

The international shipping industry is facing with increasingly strict emission regulations and depressed market; lowering the cost and increasing the efficiency is becoming a universal practice. For a long time, global community and the International Maritime organization (IMO) have been closely working together, a list of regulations and solutions are worked out; in the meantime, many energy efficiency improvement methods are proposed. In this study, global efforts in tackling climate change are summarized using a timeline approach, which includes the important outcomes of the United Nations Climate Change Conference and the IMO Marine Environment Protection Committee meeting. Then, aiming at the energy efficiency operational indicator proposed by the IMO, the mechanism analysis method is used to summarize the influencing factors of the ship’s energy efficiency. Last, these influencing factors are analyzed from different perspectives. This study provides a basis for the requirement analysis of the ship energy efficiency monitoring system and also benefits in working out energy efficiency improvement measures for the operational ships.

This article examines the distribution characteristics of the navigational environment in the Yangtze River trunk line using several information collection sensors installed on ships that navigate in this line. Through experiments on these ships, data of energy consumption and the navigational environment are collected. Water flow and waterway depth are proved to be the main influencing factors on the ship energy consumption via Spearman’s correlation analysis. Next, data of water velocity and waterway depth that cover the entire trunk line are graded using the k-means clustering algorithm. To build an evaluation matrix of navigational environment, the frequency distribution of each grade in different Yangtze River legs is counted statistically, and on this basis, similar legs are clustered using the hierarchical clustering algorithm. In this way, the waterway partition in the Yangtze River trunk line is completed. Furthermore, the distribution of the energy consumption of ships in different legs is also calculated. The study results indicate that not only the navigational environment of the Yangtze River trunk line but also the energy consumption level of ships have distinctive regional differences. Finally, the laws of the Yangtze River navigational environment are analyzed, and the corresponding energy-saving navigation strategies are proposed, which are useful for crews to operate their ships in energy-efficient and safe conditions.

Fan, A.; Yan, X., and Yin, Q., 2016. A multisource information system for monitoring and improving ship energy efficiency. Global climate change has attracted an increasing amount of attention by the public. The shipping industry is being scrutinized with regard to improving efficiency and reducing emissions. This paper explores the monitoring technology and efficiency enhancement method for a ship. First, the internal and external factors that affect a ship's energy efficiency are determined and examined. Second, an inland river ship is selected as a research target on which a multisource information system is constructed via the selection and installation of the corresponding sensors on the ship. A series of system tests have also been performed when the ship is in operation. The field tests prove that the established system is adequate for the voyage and that all of the sensors can normally monitor the parameters. In addition, a massive quantity of data for the upper, middle, and lower reaches...

In this paper, an 8kJ-pulsed seismic source with a closed cavity transducer is designed and the discharge experiment is carried out in which the selected variables are electrode materials, voltage and electrode spacing. We focus on the resistance of the plasma channel and the discharge power. By comparison, the effective power of the output of electrodes in non-metallic materials is larger than that of metallic materials. With the decrease of the voltage, the longer the duration of low resistance is. With the increase of the voltage, the electric energy conversion rate of the discharge plasma is also increased. This study provides the necessary reference for the improvement of the pulsed seismic source.

The discharge characteristics of a 8kJ-pulsed source are researched in this paper. At the beginning, the 8kJ-pulsed source is introduced, then its discharge circuit is simplified in order to the linear analysis. Furthermore, the mathematical expression of output variables are given. Finally, the experiment and simulation analysis are carried out according to the change of parameters. This study is of great significance to the optimization of pulsed power source.1

The technology of portable spark source, independent of surrounding water environment, needs to be developed for some special situations. The transfer efficiency from electric energy to seismic wave energy is the most important factor in this technology. The electrode filled with water was firstly designed to develop the pulsed discharge experiment. The seismic wave generated by pulsed discharge was measured by seismic wave detector. The relation of seismic wave amplitude and discharge parameter was observed. The electrode component is machined by stainless steel and other materials which have similar acoustic impedance with salt water to enhance the transfer efficiency from electric energy to acoustic energy. The piston-like electrodes were also designed to enhance the transfer efficiency from electric energy to mechanical energy, in which some components could be active up and down due to the impulsive force produced by pulsed discharge. The seismic wave in different electrode construction was measured and analyzed. The experiment result indicates that the amplitude of seismic wave is largest in piston-like electrodes, which also indirectly indicates that the energy of pulsed discharge in closed electrode filled with water is transferred to the ground surface layer mainly by mechanical shock.

This system includes multiple single-channel electric spark sources, the ARM processor, the host computer, a cross station, and an earthquake detector. The ARM processor transfers signal between the single channel electric spark source and the host computer. The upper computer sends out control commands to the ARM processor based on the information transmitted from the single channel electric spark source and the cross station. Seismic wave signals are transmitted to the host computer by cross station. In this invention, a number of single-channel electric spark sources are assembled in the construction site, using the ARM processor and the host computer to control them assembly, solving the difficult problems that the traditional high energy electric spark source system is difficult to carry out the exploration in mountainous areas; Multiple sources are used to discharge respectively and the time delay is recorded. And then every single-channel electric spark source is controlled alone or in a unified manner by the ARM processor and the host computer, so that the discharge energy superposition is optimized, which solves the problem of the energy shortage of the excitation seismic wave.

It is of great significance for the research of wind load in energy saving and emission reduction as wind load is one part of the ship total loads. An inland cruise ship is chosen as a research object, the wind loads on the ship including longitudinal and transverse forces and the yaw moment are calculated in wind angle of 0–180° by using CFD method, and then the numerical result is compared with those from empirical formula calculations such as Fujiware method, Blendermann method and Isherwood method. On this basis, the numerical flow field of the ship is analyzed. The result shows that wind load coefficients vary greatly with the coming wind angles; with the results from the four methods, it is concluded that the numerical calculations agree with Blendermann method very well, while Isherwood method has large discrepancy with the rest of the three methods. It should be mentioned that the wind moment could be obtained according to actual wind environment by using the method presented in this paper which could offer help for ship designing and stability assessing and the pressure distribution chart of the ship could provide reference for the optimal design of the superstructure of the ship by the CFD method used in this paper.

Some experimental results were obtained on rock fracturing without the confining pressure by using pulsed power technology. To study the effects of the stratum pressure on rock fracturing, a stratum pressure simulator with maximum pressure up to 35 MPa were development which can simulate the underground pressure of 3000 m depths. The rock samples were exploited from the sandstone mines and manufactured to a cubic block with a size of 0.4 m × 0.4 m × 0.4 m, a vertical borehole with a diameter of 0.05 m and a depth of 0.2 m was drilled in the center. Initial experimental results shown that more electric pulses are needed to generate the distinct fracture at the confining pressure, the height of crack is decreased with the increment of the confining pressure.

The rock fracturing technology can effectively enhance the reservoir permeability and conductivity of oil reservoir and improve the production of oil and gas. In this paper, high-current pulse discharge on rock fracturing was studied and a high voltage pulsed power supply was developed. The pulsed power supply is mainly composed of a high voltage high frequency charging supply, energy storage capacitors, a discharging electrodes and a safety discharging device. The maximum energy of the pulse power supply is 40kJ and working voltage is up to 20kV. The fracturing experiments are done on ten cement sandstones at low energy and high energy without confining pressure. Through the fracturing experiments of different samples, length and shape of the fracture have relations with pulse energy, the discharge voltage, discharge times and density of the rock.

In the past forty years, the supply of metal mineral resources of the buried deep within 500m is becoming more and more nervous, and the majority of metal mineral resources are getting exhausted. The exploration of concealed metallic minerals beyond 500m in depth is the focus of the current metal mineral resources prospecting. This paper mainly introduces the application of artificial seismic technology in the exploration field of mineral resources. It first introduces the development of source system at the different phases. Then, it proposes phased array electric spark source will be the focus of future research survey instrument in metal mine.

In this paper, a set of underwater plasma vibroseis system was developed, which included three big systems, i.e. charge system, discharge system and trigger system. At the same time, an experimental platform was set up through tketornix digital oscilloscope, seismic detector and desktop computer for collecting and processing data. On this basis, three working stages (breakdown, detonation and spread) of the underwater plasma were carried out the experimental research and summary. By experiment, the electrical properties of the underwater plasma were investigated under the different electrode materials, different number of electrodes, different voltages, different electrode gap spacing conditions. By using the ORIGIN data analysis software, the plasma channel resistance and the trend of the change of discharge power in time domain were obtained. It laid a foundation for choosing the optimal transducer structure and its material. In addition, the process of pulsed discharge in water was analysed. By comparing and summarizing, it found that the efficiency of corona discharge significantly is higher than that of arc discharge. This research provides references for the design of the plasma source in water.

A series of symmetric diamides were synthesized as building blocks and fully characterized to understand the interplay of alkyl chain crystallization, hydrogen bonding, and rigidity of the spacer in the solid state self-assembly process. The nature of self-assembly was investigated using single crystal X-ray diffraction studies. To have a meaningful comparison of the self-assembly process, only spacer groups were changed among the diamide molecules. Diamides 1, 2, 4, and 5 showed trans conformation in the solid lattice with the dodecyl groups on either side of the molecule, whereas 3 and 6 were in the syn conformation. In the crystal lattice, diamide 1 formed Z-shaped columns, and 3 gave close packed X-shaped dimers. Diamide 6 formed linear ribbons in the solid lattice via intra- and intermolecular hydrogen bonding. In the crystal lattice of 1-5, alkyl chains were close packed and crystallized. In all crystal lattices described here, the rigidity of the spacer group along with the interplay of hydrogen bonds, alkyl chain crystallization, and packing forces dictate the formation of thermodynamically stable supramolecular architectures with various conformations in the crystal lattice.

The solid state self-assembly of 5-alkoxyisophthalamides (1 and 2) shows monohelical structures formed through an interplay of intermolecular hydrogen bonds, interdigitation of alkyl chains, a large head-to-tail volume ratio and 1,3,5-functionalization of the central benzene ring.

A neutral urea incorporated anion receptor 1 with a tripodal pseudocavity was synthesized in good yield. The influence of preorganization and rigidity of the receptors towards anion recognition was evaluated using rigid (1) and flexible (2) receptors. Binding affinities were investigated using 1H NMR and luminescence titration methods. Receptor 1 showed high binding affinities with 1:1 stoichiometry for carboxylate anions in polar solvents. No binding was observed with small anions, presumably due to the large cavity and the rigidity of the receptor.

A versatile optimization solution combining ant colony algorithm (ACA) with fuzzy control theory (FC) was proposed for the reconfiguration problem of the distribution network in this paper. The algorithm adopted hybrid ants' behavior to produce diverse original paths, optimization of choice nodes set according to multiple constraints. At the same time, FC was added to ACA's every generation. By making use of FC's advantage of whole quick convergence, ACA's convergence speed was quickened. The feasibility and effectiveness of the algorithm are verified by series of simulated results. The simulation results show that the method this paper proposed is feasible and can obtain satisfactory effect. The model of reactive power optimiz ation is established by taking the minimum network loss as the objective. Its validity is verified through arithmetic examples of 58 nodes and a practical area network.

According to the navigation characteristics of the inland ship, a multiple-constrained model of minimum fuel consumption is established. Some information collection sensors are amounted on this ship in order to obtain the research data. Through analysis and process of these data, the regression functions between main engine fuel consumption and shaft revolution speed and between ship speed to water and revolution speed are obtained. Take the typical navigation leg for example; the model is resolved using LINGO software. Next, the energy efficient methods are further studied in two aspects that is the optimization of the navigation time and the working number of the main engine. The research results indicate that ship's fuel consumption can be efficiently reduced by extending the navigation time and reducing the working number of the main engine.

The automatic scoring of operation assessments has significant importance in the objective and fair assessment of seafarers' skill levels. Some existing problems of the current marine engineer operation assessment are analyzed. Then, four kinds of assessment modes are proposed based on automatic scoring combined with the newly released outline of seafarer operation assessment by the Ministry of Transport of the People's Republic of China. The key technology and methods applied in these four modes are described in detail. Finally, all of the assessment items are classified and counted in accordance with these four modes, which can provide a scientific reference for the marine administration to improve the current operation assessment.