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This paper aims to compare the aging behavior of water-based coatings and solvent-based coatings in sulfuric acid environments and to discuss the related mechanism.

A sulfuric acid solution with a concentration of 5 Wt.% was selected for immersion test at 23°C. The failure behavior of the coating was studied by combining the transformation rules of the macroscopic morphology and basic properties with the results of electrochemical impedance spectrum analysis.

The results showed that the surface smoothness of the water-based coating was lower than that of the solvent-based coating. The glossiness, thickness and hardness of the water-based coating exhibited more significant changes. The electrochemical test also indicated that the water-based coating was infiltrated by a large number of corrosive media, which may have induced corrosion under the coating. In contrast, the solvent-based coating showed good shielding properties, but the adhesion was seriously affected by the corrosive medium.

This work clarified the difference of failure behavior and mechanism between water-based coatings and solvent-based coatings in acidic environment and provided a theoretical basis for the selection and mechanism research of anticorrosive coatings.

The purpose of this paper is to investigate driving factors that improve the project management efficiency (PME) in centralized public procurement systems.

Employees in four public-sector organizations in China were surveyed. The structural equation modeling was employed to examine the relationship amongst those variables.

Organizational culture (OC) is an effective method to improve PME, and employee quality is the most critical factor of OC in this system. Job satisfaction (JS) is another significant contributor to PME and satisfaction with fairness of salary in this system being the key factor of JS. Job analysis (JA) has indirect influence on PME through JS and OC, whereas the job structure in this system is the most critical factor for JA.

An operational way to improve PME is to implement it from the perspectives of employee, organization and technique. At the organizational level, it is imperative to strengthen the OC by a well-structured recruitment system and to improve PME via well-design training. At the person level, both financial (i.e. income and welfare) and career incentives (i.e. promotion opportunities and a sense of belonging) are proposed to achieve employees’ JS to improve PME. At the technique level, JA approach (i.e. job rotation) is recommended to enlarge the positive influence of OC and JS on PME. These can not only ensure the management professionalism in a centralized public procurement system but can also motivate employees and maximize PME.

PME in a centralized public procurement system will be improved by addressing these key factors and their interrelationships. This provides detailed pathways for the centralized public procurement system to achieve better PME via optimal OC and JS and reasonable JA in China. In addition, the institutional and administrative traditions may vary significantly across cities, regions and countries. Therefore, such contextual differences should be taken into consideration for the improvement of PME in a centralized public procurement system.

What can big business learn from small business? Plenty. But beware—the same mistakes can kill any company, any size.

This paper aims to investigate the effects of different volume fractions of Al₂O₃-water nanofluid on flow and heat transfer under chaotic convection conditions in an L-shaped channel, comparing the difference of numerical simulation results between single-phase and Eulerian–Lagrangian models.

The correctness and accuracy of the two calculation models were verified by comparing with the experimental values in literature. An experimental model of the L-shaped channel was processed, and the laser Doppler velocimeter was used to measure the velocities of special positions in the channel. The simulated values were compared with the experimental results, and the correctness and accuracy of the simulation method were verified.

The calculated results using the two models are basically consistent. Under the condition of Reynolds number is 500, when the volume fractions of nanofluid range from 1% to 4%, the heat transfer coefficients simulated by single-phase model are 1.49%–25.80% higher than that of pure water, and simulated by Eulerian–Lagrangian model are 3.19%–27.48% higher than that of pure water. Meanwhile, the friction coefficients are barely affected. Besides, there are obvious secondary flow caused by lateral oscillations on the cross sections, and the appearance of secondary flow makes the temperature distributions uniform on the cross section and takes more heat away, thus the heat transfer performance is enhanced.

The originality of this work is to reveal the differences between single-phase and two-phase numerical simulations under different flow states. The combination of chaotic convection and nanofluid indicates the direction for further improving the heat transfer threshold.