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Fluctuation in operational energy efficiency of ships and its implications for performance appraisal
Zhang Shuang,Yuan Haichao,Sun Deping 대한조선학회 2021 International Journal of Naval Architecture and Oc Vol.13 No.1
This paper develops a dynamic regression model to quantify the contribution of key external factors to operational energy efficiency of ships. On this basis, kernel density estimation is applied to explore distribution patterns of fluctuations in operational performance. An empirical analysis based on these methods show that distribution of fluctuations in Energy Efficiency Operational Indicator (EEOI) is leptokurtic and fat tailed, rather than a normal one. Around 85% of fluctuations in EEOI can be jointly explained by capacity utilization and sailing speed, while the rest depend on other external factors largely beyond control. The variations in capacity utilization and sailing speed cannot be fully passed on to the energy efficiency performance of ships, due to complex interactions between various external factors. The application of the methods is demonstrated, showing a potential approach to develop a rating mechanism for use in the legally binding framework on operational energy efficiency of ships.
New constructive model for structures soil
Zhang, Sheng,Li, Haichao,Teng, Jidong Techno-Press 2016 Geomechanics & engineering Vol.11 No.5
A theoretical study of the behavior of structured soils is presented herein. By introducing the effect of soil structure and loading history into the Cam Clay model, a new model was formulated. The concept of differing void ratios was modified to combine structural parameters and the over consolidation ratio, and an evolution law was proposed. Upon introducing the concept of the subloading yield surface, a new two-yield surface model was obtained. The predicted results were compared to the experimental data, demonstrating that the new model provided satisfactory qualitative modeling of many important features of structured soils.
Development of microwave assisted oxidative desulfurization of petroleum oils: A review
Hui Shang,Zhichang Liu,Haichao Zhang,Wei Du 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.5
This paper provides a general overview of microwave applications in petroleum oxidative desulfurization (ODS). It was concluded that, as compared with conventional heating technologies,milder reaction conditions could be used and higher ODS rate could be achieved under microwave treatment. It was also found that microwave power level, treatment time, temperature, oxidizing agent dosage, microwave equipment and catalyst are the key operating factors influencing the ODS efficiency. A best removal rate of 96% achieved for diesel. The main challenges are developing high efficiency, novel techniques and apparatuses to remove sulfur from oils in a commercial process.
Low-Frequency Vibration Control of Metro Slab Track Based on Locally Resonant Theory
Chao Li,Sifeng Zhang,Qian Liu,Chong Zhou,Haichao Qin,Luyu Zhang,Minghu Zhai 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.6
Vibration control has always been one of the research hotspots in the field of urban metro system. Due to the unsatisfactory application effect of traditional vibration damping technology in practice, a novel method, based on the locally resonant theory, was introduced into metro vibration damping system to improve the low-frequency vibration reduction effect. Meanwhile, the new metro vibration reduction slab track was designed. Furthermore, the coupled model of the metro vehicle-slab track was established and verified, and the reduction effect of the new metro slab track on low-frequency vibration under the action of metro vehicles was analyzed. Results show that: 1) The new vibration reduction slab track is really in control of the low-frequency vibration (50 − 100 Hz), and the attenuation effect can reach 10 dB; 2) The new slab track has multiple low-frequency vibration band gaps, which can achieve multi-frequency vibration reduction; 3) The new slab track can reduce the vibration acceleration of the track, which can improve the comfort level of the vehicle. Therefore, the local resonance theory enriches the existing metro vibration reduction design theory and provides a method for the design of the metro vibration control.
Development of microwave induced hydrodesulfurization of petroleum streams: A review
Hui Shang,Wei Du,Zhichang Liu,Haichao Zhang 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.4
This paper provides a general overview of microwave applications in hydrodesulfurization (HDS) of various petroleum streams. Deep desulfurization is required for petroleum streams due to stringent sulfur specifications to meet environmental norms. The progress achieved during recent years in catalyst-based HDS technologies is illustrated by using microwaves due to its unique selective and volumetric heating capacity. Based on literature reports, it may be concluded that microwave assisted desulfurization of petroleum streams can be successfully performed under less severe conditions, with significant advantages. This is expected to result in savings in utilities, catalyst consumption, eventually leading to increased fuel yields.