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In this article, to meet the requirements of marine engine room simulator on both the simulation speed and simulation accuracy, a mean value engine model (MVEM) for the 7S80ME-C9.2 marine two-stroke diesel engine was developed and validated in the MATLAB/Simulink environment. In consideration of the significant influence of turbocharger compressor on both the engine steady state performance and transient response, a novel compressor model (mass flow rate and isentropic efficiency model) based on a previous study carried out by the first author was proposed with the aim of achieving satisfactory simulation accuracy within the whole engine operating envelope. The predictive and extrapolative capability of the proposed compressor model was validated by carrying out simulation experiments and analyzing the simulation results under steady state condition and during transient process. To make the traditional MVEM capable of predicting in-cylinder pressure trace, the cylinder pressure analytic model proposed by Eriksson and Andersson for the four-stroke SI (spark ignition) engine was adapted to the 7S80ME-C9.2 marine two-stroke diesel engine based on the characteristic of in-cylinder pressure trace of this type of engine and then coupled to the MVEM developed in this paper. Since there is no need to solve any differential equation as it is done in the 0-D model, the advantage of MVEM in running speed is not impaired. For achieving satisfactory simulation accuracy by using the analytic model, the model parameters were calibrated elaborately by using engine measured data and a 0-D model and the relevant tuning procedure was discussed in detail.

To deal with the increasingly stringent energy crisis and atmospheric pollution problems, biodiesel is regarded as one of the alternative biofuels with great potential for replacing the conventional diesel fuel, thus it is necessary to investigate the influences of addition of biodiesel to conventional diesel fuel on the combustion products. To this end, Jatropha biodiesel is taken as an example and under the assumption that all the combustion products are at chemical equilibrium, a system of nonlinear equations with the equilibrium concentrations of 10 combustion products as the unknown variables is constructed based on the equilibrium constant method and the numerical solutions are obtained by applying Newton-Raphson iterative method. On this basis the influences of biodiesel blending ratio on the equilibrium concentrations of the combustion products and the thermodynamic properties of burned gases mixture is investigated. The simulation results show that the addition of biodiesel does not cause significant influences on the equilibrium concentrations of combustion product, and as the three major greenhouse and poisonous gases, the relative changes of equilibrium concentration for CO2, NO and CO are less than 3.52% but with unclear trends and the influence is more significant at the “fuel rich” condition; on the other hand, the mass-based combustion products rates of CO2, NO and CO for a unity of blended fuel mass increases with blending ratio. For the thermodynamic properties of burned gases mixture, it is observed that both the constant-pressure and -volume specific heat increase slightly. The model presented here can be integrated into the engine dynamic simulation model conveniently, which lays the foundation for investigating the influence of addition of biodiesel on the engine power, economic and emission performance.

A compressor is an indispensable component of marine large two-stroke diesel engines. For this type of engine, the compressor mass flow rate and isentropic efficiency empirical models are preferred for both the working cycle dynamic simulation research and the design and testing of control and diagnostics algorithms due to their compact and simple structures, and satisfactory prediction accuracy. Due to absence of comprehensive applicable and comparative research on compressor mass flow rate and isentropic efficiency empirical models for large-scale marine compressors in the literature, two marine compressors with different size, flow rate range, and speed range were selected as research objects in this paper, and a relevant study was conducted to compare and analyze the prediction ability of several classical models, and some recently proposed compressor mass flow rate and isentropic efficiency empirical models. The range of this comparative study includes the prediction accuracy in the design operating area and the extrapolation ability in off-design operating areas. Based on the obtained research results, several guidelines are summarized, which can be followed when developing compressor mathematical models, especially for marine applications. In addition, several research interests are discussed and presented, which can be further studied in the future.

MTS1, which encodes a protein named p16, is an important gene involved in tumorigenesis. To increase the expression of p16 in Escherichia coli, MTS1 was synthesized de novo by recursive PCR, with codons optimized towards E. coli. Studies indicate that N-terminal amino acids of p16 had negative impact on its expression in E. coli. The function of p16DeltaN8 is not affected by the absence of N-terminal eight amino acids, compared with p16. p16DeltaN8 was expressed in E. coli, which reached 22% of total cell proteins. Purified p16DeltaN8 (purity was 98%) was delivered into A875 (melanoma), MCF7 (breast cancer), and HeLa (cervical cancer) cells by lipofectin. Results show purified p16DeltaN8 remarkably inhibited the growth of A875 and MCF7 cells, whereas it had little effect on HeLa cells.