Vegetable-oil upgrading over Ni based bimetallic catalysts

Zuo Hao,Seong Chan Lee,Hee Chul Woo 한국에너지기후변화학회 2017 한국에너지기후변화학회 학술대회 Vol.2017 No.11

Analysis of thermal performance and thermal stress using two-dimensional thermoelastic model for a 50 MWe external cylindrical solar receiver

Hao Zhou,Yuhang Zuo,Yawei Li,Mingxi Zhou 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.10

The thermal stress arisen from highly inhomogeneous solar radiation and temperature distribution during operation is mainly responsible for the failure of the central receiver. In the present study, the analytical approximation method, finite volume method and 2D thermoelastic analytical approach were used in combination to obtain the thermal characteristics of a 50 MWe external cylindrical receiver. The results demonstrated that the direct normal irradiance and tube surface absorptivity significantly affected the thermal stress. The axial distribution of the equivalent thermal stress at θ = 0° consisted with the surface solar flux distribution, and the maximum equivalent stress was underestimated by 30.0 % with the homogeneous surface solar flux distribution. Compared with molten salt flowing into the receiver from the south, the maximum equivalent stress and maximum wall temperature of molten salt flowing from the north are 16.3 % higher and 8.1 % lower, respectively.

ON THE LAGRANGIAN TIDAL RESIDUAL CIRCULATION IN THE BOHAI SEA

Hao Wei,Liang Zhao,Shi Zuo Feng 한국해안해양공학회 1999 학술강연회 발표논문초록집 Vol.1 No.1

Tidal residual is very important to the transport in the coastal sea. In our point of view Lagrangian time averaged residual is relevent to the Eulerian one to embody the coastal circulation. Tidal system of Bohai Sea is simulated by HAMSOM and both of two kinds of tidal residual are calculated at the mean time. There are significant differences between them in some area.

Nonlinear boundary parameter identification of bridges based on temperature-induced strains

Zuo-Cai Wang,Guo-Peng Zha,Wei-Xin Ren,Ke Hu,Hao Yang 국제구조공학회 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.68 No.5

Temperature-induced responses, such as strains and displacements, are related to the boundary conditions. Therefore, it is required to determine the boundary conditions to establish a reliable bridge model for temperature-induced responses analysis. Particularly, bridge bearings usually present nonlinear behavior with an increase in load, and the nonlinear boundary conditions cause significant effect on temperature-induced responses. In this paper, the bridge nonlinear boundary conditions were simulated as bilinear translational or rotational springs, and the boundary parameters of the bilinear springs were identified based on the measured temperature-induced responses. First of all, the temperature-induced responses of a simply support beam with nonlinear translational and rotational springs subjected to various temperature loads were analyzed. The simulated temperature-induced strains and displacements were assumed as measured data. To identify the nonlinear translational and rotational boundary parameters of the bridge, the objective function based on the temperature-induced responses is then created, and the nonlinear boundary parameters were further identified by using the nonlinear least squares optimization algorithm. Then, a beam structure with nonlinear translational and rotational springs was simulated as a numerical example, and the nonlinear boundary parameters were identified based on the proposed method. The numerical results show that the proposed method can effectively identify the parameters of the nonlinear boundary conditions. Finally, the boundary parameters of a real arch bridge were identified based on the measured strain data and the proposed method. Since the bearings of the real bridge do not perform nonlinear behavior, only the linear boundary parameters of the bridge model were identified. Based on the bridge model and the identified boundary conditions, the temperature-induced strains were recalculated to compare with the measured strain data. The recalculated temperature-induced strains are in a good agreement with the real measured data.

A GPU-Accelerated Hydrodynamic Model for Urban Rainstorm Inundation Simulation: A Case Study in China

Hao Han,Jingming Hou,Zongxue Xu,Haixiao Jing,Jiahui Gong,Depeng Zuo,Bingyao Li,Shaoxiong Yang,Yongde Kang,Run Wang 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.3

Frequent urban rainstorm inundations can cause serious damages to human life and social economy. Reliable simulation of urban rainstorm inundation is an effective approach for performing flood risk analysis to reduce losses. In this work, a full 2D high-performance hydrodynamic model for urban rainstorm inundation simulation based on Graphic Processing Unit (GPU) was developed. The idealized V-shape catchment and sponge city district of Fengxi New City were selected as the study areas to assess performance of the model. The model was validated against analytical benchmark results of the idealized V-catchment test which show good agreement between the modelled flow and analytical solutions. The model was then applied to simulate actual urban rainstorm inundation process under measured rainfall. The results indicated that the model can be applied to high-resolution urban region simulations. Specifically, the validation results indicated that the proposed model had a good performance, with an accepted error of less than 15%. When applied to compute the Fengxi New city under design rainstorms with different annual return periods of 1, 5, 10, 20, 50, and 100 years, it was found that the model effectively evaluated the temporal and spatial variation process of urban inundation, and quantitatively investigated flood risks according to the water depth change. The model has been substantially accelerated on GPU to quickly predict urbaninundation. The accuracy and rapid simulation speed of the model were verified based on the actual study area. Therefore, the proposed model can help to predict the dynamic processes of urban flood inundation and thus reduce flood inundation disasters. This is essential for future optimal sponge urban construction planning in China.

The Influence of Construction Scheme of Asymmetric Three-Cabin Utility Tunnelling on the Surface Settlement Behaviour

Zuo Chun Li,Gui He Wang,Jun Wei Hao,Yao Zhou,Xiao Yang Wang,Heng Xuan,Feng Huang 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.9

The asymmetric three-cabin structure is one of the favourite choices in urban utility tunnel engineering, as it can provide a higher space utilization and clearer classification for pipelines. However, few work has been done on utility tunnel in such special cross-section during undercutting construction until now. Besides, as the loose soil layers such as sand and silt are often encountered during the utility tunnelling, its influence on surface settlement become one of the main concerns. This study focuses on the influence of the construction scheme on the surface settlement details for an asymmetric three-cabin utility tunnel. A 3D finite element method (FEM) model was established including both the stratum and a utility tunnel based on the Beijing Daxing International Airport (BDIA) Expressway Urban Utility Tunnel project. With this model, the behaviour of the surface settlement with the undercutting construction of the utility tunnel was investigated, and the causes and values of surface settlement in five construction stages were analyzed. By changing the construction spacing and sequence of mid and side cabins, the surface settlement and structural deformation were compared. The numerical results demonstrated a strong correlation between the cross-section shape and surface settlement characteristics. And the symmetry line of the surface settlement trough was offset by 1 m to the side with the larger cross-section. The second (excavation of upper bench in mid-cabin) and fourth (excavation of upper bench in side-cabin) stages caused the largest surface settlement, which were 41.9% and 18.07% of the total settlement, respectively. In addition, after optimizing the field tunnelling scheme, the surface settlement was reduced by 31.9% using the side-tunnel first construction sequence. The proposed numerical model is able to predict the settlement characteristics in each construction stage, which is important and provides a basis for further studies on the surface settlement mechanism and optimal design of the asymmetric three-cabin utility tunnelling scheme.

Intensity modulation-based fibre optic vibration sensor using an aperture within a proof mass

Zuo, Ze-Wei,Hao, Yi,Choi, Sang-Jin,Song, Minho,Kim, Young-Chon,Pan, Jae-Kyung IET 2017 IET science, measurement & technology Vol.11 No.1

<P>The authors propose an intensity modulation-based fibre optic vibration sensor (FOVS) using an aperture within a proof mass. It consists of an optical collimator, a mass-spring structure, a mirror, and a rectangular aperture. They verify its feasibility via experimental demonstration. For the feasibility test, they implement three lab-based prototype FOVSs with different natural frequencies and measure each FOVS's frequency response according to the base vibration and sensitivity. The experimental results for three lab-based prototype FOVSs show the sensitivities of 163, 183, and 206 mV/g, the minimum detectable accelerations of 0.082, 0.086, and 0.082 mg, and the dynamic ranges of 18-45, 26-52, and 20-120 Hz, respectively. They also experimentally demonstrate its remote sensing and multipoint sensing characteristics. The proposed FOVS has the virtues of easy controllable sensitivity and dynamic range, simple structure, and remote sensing and multipoint sensing characteristics.</P>

Simultaneous out-of-plane and in-plane vibration mitigations of offshore monopile wind turbines by tuned mass dampers

Haoran Zuo,Kaiming Bi,Hong Hao 국제구조공학회 2020 Smart Structures and Systems, An International Jou Vol.26 No.4

To effectively extract the vast wind resource, offshore wind turbines are designed with large rotor and slender tower, which makes them vulnerable to external vibration sources such as wind and wave loads. Substantial research efforts have been devoted to mitigate the unwanted vibrations of offshore wind turbines to ensure their serviceability and safety in the normal working condition. However, most previous studies investigated the vibration control of wind turbines in one direction only, i.e., either the out-of-plane or in-plane direction. In reality, wind turbines inevitably vibrate in both directions when they are subjected to the external excitations. The studies on both the in-plane and out-of-plane vibration control of wind turbines are, however, scarce. In the present study, the NREL 5 MW wind turbine is taken as an example, a detailed three-dimensional (3D) Finite Element (FE) model of the wind turbine is developed in ABAQUS. To simultaneously control the in-plane and out-of-plane vibrations induced by the combined wind and wave loads, another carefully designed (i.e., tuned) spring and dashpot are added to the perpendicular direction of each Tuned Mass Damper (TMD) system that is used to control the vibrations of the tower and blades in one particular direction. With this simple modification, a bi-directional TMD system is formed and the vibrations in both the out-of-plane and in-plane directions are simultaneously suppressed. To examine the control effectiveness, the responses of the wind turbine without control, with separate TMD system and the proposed bi-directional TMD system are calculated and compared. Numerical results show that the bi-directional TMD system can simultaneously control the out-of-plane and in-plane vibrations of the wind turbine without changing too much of the conventional design of the control system. The bi-directional control system therefore could be a cost-effective solution to mitigate the bi-directional vibrations of offshore wind turbines.

BMB : Reports ; An inhibitory role of NEK6 in TGFβ/Smad signaling pathway

( Jie Zuo ),( Haijie Ma ),( Hao Cai ),( Yanhua Wu ),( Wei Jiang ),( Long Yu ) 생화학분자생물학회(구 한국생화학분자생물학회) 2015 BMB Reports Vol.48 No.8

The NEK6 (NIMA-related kinases 6) is reported to play po-tential roles in tumorigenesis. Although it is suggested to function in several cellular pathways, the underlying mechanism in tumorigenesis is still largely unknown. In the present study, we discovered interaction of NEK6 with Smad4, a key member of transforming growth factor beta (TGFβ) pathway. Over-expression of NEK6 in hepatocellular carcinoma (HCC) cell lines suppresses TGFβ- mediated transcription activity in a kinase activity-dependent manner. In addition, NEK6 suppresses the cell growth arrest induced by TGFβ. Mechanically, NEK6 blocks nuclear translocation of Smad4, which is essential for TGF β function. Moreover, we identified that NEK6 could be regulated by TGFβ and hypoxia. Our study sheds new light on the roles of NEK6 in canonical TGFβ/Smad pathway and tum-origenesis. [BMB Reports 2015; 48(8): 473-478]

THREE-SPEED TRANSMISSION SYSTEM FOR PURELYELECTRIC VEHICLES

Z. ZHANG,C. ZUO,W. HAO,Y. ZUO,X. L. ZHAO,M. ZHANG 한국자동차공학회 2013 International journal of automotive technology Vol.14 No.5

This paper discusses the necessity of using a transmission system to improve the energy efficiency of purelyelectric vehicles (EVs). The energy efficiency of an electric motor varies at different operating points to meet the output powerdemand. The three gear ratios of a transmission system can maintain the motor speed within a stable region with relativelyhigh energy efficiency, while various vehicle speeds are needed. This work is based on a light EV prototype. The optimizedgear ratios of this transmission result in a considerably reduced energy consumption of 9.3% compared with conventional EVswith single-speed reducers under the condition of the Urban Dynamometer Driving Schedule driving cycle. Thus, thetransmission system is necessary to improve the energy efficiency of EVs.