Transformerless Bidirectional DC-DC Converter for Battery Storage System with High Voltage Gain

Hailong Zhang,Yafei Chen,Chang-Su Shin,Sung-Jun Park,Dong-Hee Kim 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

Bidirectional DC-DC converters with wide voltage conversion ratio are essential in energy storage systems. In these systems (ESS), cost effective design is important factor, therefore, it needs to be designed with small numbers of component. This paper proposes a family of high voltage gain bidirectional converter based on the integration of Boost converter with Ćuk, SEPIC, BUCK-BOOST converters respectively. Detail comparisons are progressed in terms of operating mode, numbers of component, and efficiency. The experiment results are carried to verify the proposed converter family. The results show that converter I present the highest efficiency in boost mode (92%) and in buck mode (92.2%).

Bidirectional DC-DC Converter Based on Quasi-Sepic for Battery Charging System

Zhang, Hailong,Chen, Yafei,Kim, Dong-Hee,Park, Sung-Jun,Park, Seong-Mi The Korean Society of Industry Convergence 2020 한국산업융합학회 논문집 Vol.23 No.2

In order to satisfy the voltage levels of the low voltage battery side and high voltage DC bus, a high voltage gain with bidirectional operation is required. In this system, the cost effectiveness of the design is a critical factor; therefore, the system should be designed using a small number of components. This paper propose a novel bidirectional converter composed with a quasi-sepic and switched-indictor network. The proposed converter consists a small number of components with a high voltage gain ratio. Detailed analysis are made with respect to the operating mode, number of components, voltage and current ripple and efficiency. To verify performance of the proposed converter, simulation was performed is this paper. The simulation results are shown to verify the feasibility and performance of the proposed bidirectional converter.

Bidirectional DC-DC Converter Based on Quasi-Sepic for Battery Charging System

Hailong Zhang,Yafei Chen,Dong-Hee Kim,Sung-Jun Park,Seong-Mi Park 한국산업융합학회 2020 한국산업융합학회 논문집 Vol.23 No.2

In order to satisfy the voltage levels of the low voltage battery side and high voltage DC bus, a high voltage gain with bidirectional operation is required. In this system, the cost effectiveness of the design is a critical factor; therefore, the system should be designed using a small number of components. This paper propose a novel bidirectional converter composed with a quasi-sepic and switched-indictor network. The proposed converter consists a small number of components with a high voltage gain ratio. Detailed analysis are made with respect to the operating mode, number of components, voltage and current ripple and efficiency. To verify performance of the proposed converter, simulation was performed is this paper. The simulation results are shown to verify the feasibility and performance of the proposed bidirectional converter.

과황산의 열적활성화 및 염소계용제의 산화분해

장하이롱 ( Hailong Zhang ),권희원 ( Hee-won Kwon ),최정학 ( Jeong-hak Choi ),김영훈 ( Young-hun Kim ) 한국환경과학회 2017 한국환경과학회지 Vol.26 No.11

Oxidative degradation of chlorinated ethenes was carried out using heat-activated persulfate. The activation rate of persulfate was dependent on the temperature and the activation reaction rate could be explained based on the Arrhenius equation. The activation energy of persulfate was 19.3 kcal/mol under the assumption that the reaction between the sulfate radical and tricholoroethene (TCE) is very fast. Activation could be achieved at a moderate temperature, so that the adverse effects due to high temperature in the soil environment were mitigated. The reaction rate of TCE was directly proportional to the concentration of persulfate, indicating that the remediation rate can be controlled by the concentration of the injected persulfate. The solution was acidized after the oxidation, and this was dependent on the oxidation temperature. The consumption rate of persulfate was high in the presence of the target organic, but the self-decomposition rate became very low as the target was completely removed.

Dynamics Modeling and Simulation Analysis for Wood High-speed Motorized Spindle

Wei Zhang,Shuangyong Wang,Yang Zhang,Hailong He,Pengfei Zhang 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.1

In this paper, considering the main factor in the high-speed processing, including the mass of the spindle, the offset of the centroid, bearing span, bearing stiffness and spindle speed , a dynamic model of the spindle-bearing system is established. After carrying out a simulation by Matlab, vibration curve of the spindle-bearing system is obtained, and influence on the vibration characteristics of the spindle bearing system by the centroid offset is analyzed. These works provide the basis for further studies on the vibration mechanism of the high-speed motorized spindle.

Optimization of Mix Proportion of Self-compacting Concrete Based on Single Fluid Model

Xiuzhi Zhang,Chong Zhang,Mengdi Bi,Haibo Yang,Hailong Sun,Ru Mu 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.3

The study aims to optimize the mix proportion of self-compacting concrete according to the workability and compressive strength. Firstly, based on computational fluid dynamics, the flowability and filling ability of self-compacting concrete were simulated by the single-fluid model to verify the single-fluid model. And then, the simulation of casting a pre-cambered composite beam was carried out. In the end, the mix proportion was optimized considering the filling ability and the compressive strength of self-compacting concrete. The results showed that increasing sand rate can improve the workability and decrease the rheological parameters of self-compacting concrete. The mixture with a 45% sand ratio in the case of 3% silica fume alone or 43% sand ratio in the case of 30% granulated blast furnace slag and 3% silica fume had adequate filling ability and excellent long term compressive strength. Moreover, the model can be used to simulate the filling ability and passing capacity of self-compacting concrete and the maximum error between the simulation results and the actual measured value is 4.80%. When the concrete mixture is considered to be uniform, namely, without considering the effect of the aggregates, the single-fluid model can simulate the casting of self-compacting concrete.

THE IMPACT OF COMPARATIVE PRICE ON CONSUMER TOLERANCE FOR SERVICE FAILURE

Hailong Yang,Yuanyu Zhang,Liangjing Che 글로벌지식마케팅경영학회 2018 Global Marketing Conference Vol.2018 No.07

This research was conducted in order to examine the effect of comparative price on consumers’ reactions to service failure in the loyalty program. The current study finds that under condition of lower level of persuasion knowledge, compared to single retail price, comparative price would mitigate consumers’ negative emotion in the context of service failure, which in turn improves customers’ tolerance. The authors test this prediction in two experiments. Experiment 1 aimed to provide an initial exploration of hypothesis by employing a between-subjects design. This experiment recruited undergraduate students at Suzhou University to complete an online survey. After reading the scenario of service failure, participants were asked to answer a series of questions about their intension of spreading negative word of mouth (NWOM). A one-way ANOVA on intention of spreading NWOM suggested that the NWOM activity was significantly lower in the group of comparative prices than in the group of single retail price. In experiment 2, the authors measured angry and intension to complain when participants finished reading the scenario of service failure. Furthermore, one week later the authors measured price tactic persuasion knowledge of participants. The bootstrap method (number of bootstrap samples = 5000, level of confidence = .95) was used. The results showed that customers’ angry level mediated the effect of comparative price on intension of complaint. The authors further conducted a mediated moderation analysis with the participants in the high- and low-persuasive-knowledge conditions. The results indicated the indirect effect of the comparative price on intention to complain was mediated by customers’ angry when they have low persuasive knowledge, whereas the mediation effect of customer’s angry level was no longer significant in the higher persuasive-knowledge condition. To summarize, this research suggested that comparative price would exert a marked impact on the tolerance of members of loyalty program in the context of service failure. The present paper adds to the existing comparative price literatures by confirming its impact on consumers’ judgment in the context of service failure even if they are all members of loyalty program and informed with information of discounted size in advance. Given the special meaning of NWOM and complaint, current paper provides implications for marketing practices.

Impact of numerical choices on water conservation in the E3SM Atmosphere Model version 1 (EAMv1)

Zhang, Kai,Rasch, Philip J.,Taylor, Mark A.,Wan, Hui,Leung, Ruby,Ma, Po-Lun,Golaz, Jean-Christophe,Wolfe, Jon,Lin, Wuyin,Singh, Balwinder,Burrows, Susannah,Yoon, Jin-Ho,Wang, Hailong,Qian, Yun,Tang, Q Copernicus GmbH 2018 Geoscientific model development Vol.11 No.5

<P><p><strong>Abstract.</strong> The conservation of total water is an important numerical feature for global Earth system models. Even small conservation problems in the water budget can lead to systematic errors in century-long simulations. This study quantifies and reduces various sources of water conservation error in the atmosphere component of the Energy Exascale Earth System Model.</p> <p>Several sources of water conservation error have been identified during the development of the version 1 (V1) model. The largest errors result from the numerical coupling between the resolved dynamics and the parameterized sub-grid physics. A hybrid coupling using different methods for fluid dynamics and tracer transport provides a reduction of water conservation error by a factor of 50 at 1<span class='inline-formula'>^∘</span> horizontal resolution as well as consistent improvements at other resolutions. The second largest error source is the use of an overly simplified relationship between the surface moisture flux and latent heat flux at the interface between the host model and the turbulence parameterization. This error can be prevented by applying the same (correct) relationship throughout the entire model. Two additional types of conservation error that result from correcting the surface moisture flux and clipping negative water concentrations can be avoided by using mass-conserving fixers. With all four error sources addressed, the water conservation error in the V1 model becomes negligible and insensitive to the horizontal resolution. The associated changes in the long-term statistics of the main atmospheric features are small.</p> <p>A sensitivity analysis is carried out to show that the magnitudes of the conservation errors in early V1 versions decrease strongly with temporal resolution but increase with horizontal resolution. The increased vertical resolution in V1 results in a very thin model layer at the Earth's surface, which amplifies the conservation error associated with the surface moisture flux correction. We note that for some of the identified error sources, the proposed fixers are remedies rather than solutions to the problems at their roots. Future improvements in time integration would be beneficial for V1.</p> </P>

In Vitro Effects of SB202190 on Echinococcus granulosus

Hailong Lv,Siyuan Li,Jing Zhang,Weihua Liang,Xiaoling Mu,Yufeng Jiang 대한기생충학열대의학회 2013 The Korean Journal of Parasitology Vol.51 No.2

Spillage of cyst contents during surgical operation is the major cause of recurrence after hydatid cyst surgery. Instillation of a scolicidal agent into a hepatic hydatid cyst is the most commonly employed measure to prevent this complication. SB202190 is a pyridinyl imidazole derivative and is known to be a specific inhibitor of p38 MAPK. In the present study, the scolicidal effect of SB202190 was investigated. Freshly isolated Echinococcus granulosus protoscolices were subjected to SB202190 treatment (10, 20, 40, and 80 μM), and the effects on parasite viability were monitored by trypan blue staining. Corresponding effects were visualized by scanning and transmission electron microscopy. Dose-dependent protoscolex death within a few days of SB202190 treatment was observed. Although the in vitro scolicidal effect of SB202190 was satisfactory, the in vivo efficacy of this drug and also possible side effects remain to be further investigated.

Isolation of Cellulose from Wheat Straw and Its Utilization for the Preparation of Carboxymethyl Cellulose

Hailong Li,Hai-Rong Zhang,Lian Xiong,Xuefang Chen,Can Wang,Chao Huang,Xin-De Chen 한국섬유공학회 2019 Fibers and polymers Vol.20 No.5

Cellulose was isolated from wheat straw by the combined pretreatment including dilute acid hydrolysis, ethanolextraction, and alkaline H2O2 delignification. The effects of varying the parameters on carboxymethylation on isolatedcellulose were investigated. Furthermore, the chemical structure of carboxymethyl cellulose (CMC) prepared from wheatstraw was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopeanalysis. The isolated cellulose is mainly composed of cellulose without hemicellulose and with minors of lignin and ash. The optimal conditions for carboxymethylation were base concentration, 20 %; reaction temperature, 70 oC; reaction time,2 h; mass ratio of etherifying agent to cellulose, 1.75. Under the optimized conditions, CMC with high degree of substitution(0.88) and low viscosity (18 mPa·s) was synthesized. Chemical structural characterization showed the feasibility of thepreparation of CMC from wheat straw. The constituents of wheat straw would be maximally utilized by the proposed method.