An experimental study on low-velocity nonlinear flow in vuggy carbonate reservoirs

Haitao Wu,Fujun Li,Jiawen Liu,Jiang Chen,Xiaowei Lv,Wei Hu 한국자원공학회 2016 Geosystem engineering Vol.19 No.4

Vuggy carbonate reservoirs in the Middle East, which have characteristics such as high porosity, low permeability, and few fractures, are significantly different from fractured-vuggy carbonate reservoirs. In this study, single-phase flow experiments and core mercury injection experiments were conducted to analyze the pore size distribution and low-velocity nonlinear flow characteristics of vuggy carbonate rocks in Halfaya oilfield. The results show that the relationship between pseudo-threshold pressure gradient and permeability in matrix carbonate rocks is linear. However, vuggy type does not exhibit the same linear relationship. Compared with matrix type, vuggy carbonate rock has a nonlinear flow zone when the pressure gradient is comparatively low and the nonlinear flow characteristics are quite different from those of low-permeability sandstone reservoirs. Because of the multi-polarization of flow channel radius in vuggy carbonate rocks, fluid stepwise starts flowing as the pressure gradient increases. Vuggy carbonate rock has a pseudo-threshold pressure gradient during the low-velocity flow, but the actual threshold pressure gradient does not exist. The concept of whole channel flow pressure gradient is presented in this paper. The results contribute to improve the understanding of low-velocity flow characteristics of vuggy carbonate reservoirs.

Optimization Model of Reliable Data Storage in Cloud Environment Using Genetic Algorithm

Feng Liu,Haitao Wu,Xiaochun Lu,Xiyang Liu 보안공학연구지원센터 2014 International Journal of Grid and Distributed Comp Vol.7 No.6

Massive data storage is one of the great challenges for cloud computing service, and reliable storage of sensitive data directly affects quality of storage service. In this paper, based on analysis of data storage process in cloud environment, the cost of massive data storage is considered to be comprised of data storage price, data migration and communication; and the storage reliability consists of data transmission reliability and hardware dependability. A multi-objective optimization model for reliable massive storage is proposed, in which storage cost and reliability are the objectives. Then, a genetic algorithm for solving the model is designed. Finally, experimental results indicate that the proposed model is positive and effective.

A fluorescent probe for colorimetric detection of bisulfite and application in sugar and red wine

Haitao Chen,Xiaoming Wu,Jialin Wang,Hao Wang,Feiyan Tao,Shaoxiang Yang,Hongyu Tian,Yongguo Liu,Baoguo Sun 한국식품과학회 2019 Food Science and Biotechnology Vol.28 No.4

A new fluorescent probe made from (E)-2-(benzo[d]thiazol-2-yl)-3-(6-hydroxynaphthalen-2-yl) acrylonitrile(Probe 1) was synthesized for the determination ofbisulfite concentrations in real food samples (red wine andsugar). Adding bisulfite to a Probe 1 solution caused amarked decrease in fluorescence intensity and a visualcolor change from yellow to light yellow. This distinctcolor response indicates that Probe 1 could be used as avisual sensor for bisulfite. Probe 1 can detect bisulfitequantitatively in the range 0–400 lM with a detection limitof 0.10 lM. This makes Probe 1 a convenient signalinginstrument for determining bisulfite levels in sugar and redwine samples.

Microstructure and Texture Evolution of Rolled Plate for Cu–15Cr In-Situ Composite

XuDong Wu,LvQi Zhu,RuiRui Liu,HaiTao Zhou 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.11

The microstructure and texture of different rolling processes in situ Cu–15Cr sheets are studied. The results show that thesecond phase Cr in the material gradually become broken, flattened, merged and homogenized from dendritic state to orientedthin lath. Meanwhile, the texture in distributed copper matrix grains finally forms Brass {110}<112>, Goss {001}<110>and Copper {112}<111> textures along with Cr phase texture of randomly distributed α-fiber (<110> fiber) and γ-fiber(<111> fiber) texture. Based on VPSC (visco-plastic self-consistent model), the texture of cold rolled Cu–15Cr compositeis simulated, and the simulation result indicates that obvious twinning effect in the copper matrix appears with a feature ofa special texture evolution law of Goss.

DYNAMICS CHARACTERISTICS ANALYSIS AND CONTROL OF FWID EV

Dongmei Wu,Haitao Ding,Changqing Du 한국자동차공학회 2018 International journal of automotive technology Vol.19 No.1

Compared with internal combustion engine (ICE) vehicles, four-wheel-independently-drive electric vehicles (FWID EV) have significant advantages, such as more controlled degree of freedom (DOF), higher energy efficiency and faster torque response of an electric motor. The influence of these advantages and other characteristics on vehicle dynamics control need to be evaluated in detail. This paper firstly analyzed the dynamics characteristics of FWID EV, including the feasible region of vehicle global force, the improvement of powertrain energy efficiency and the time-delays of electric motor torque in the direct yaw moment feedback control system. In this way, the influence of electric motor output power limit, road friction coefficient and the wheel torque response on the stability control, as well as the impact of motor idle loss on the torque distribution method were illustrated clearly. Then a vehicle dynamics control method based on the vehicle stability state was proposed. In normal driving condition, the powertrain energy efficiency can be improved by torque distribution between front and rear wheels. In extreme driving condition, the electric motors combined with the electro-hydraulic braking system were employed as actuators for direct yaw moment control. Simulation results show that dynamics control which take full advantages of the more controlled freedom and the motor torque response characteristics improve the vehicle stability better than the control based on the hydraulic braking system of conventional vehicle. Furthermore, some road tests in a real vehicle were conducted to evaluate the performance of proposed control method.

An Mechatronics Coupling Design Approach for Aerostatic Bearing Spindles

Quanhui Wu,Yazhou Sun,Wanqun Chen,Haitao Liu,Xichun Luo 한국정밀공학회 2019 International Journal of Precision Engineering and Vol.20 No.7

In this paper, a new design approach for aerostatic bearing spindles (ABS) is firstly proposed which takes into account of the interactions between the mechanical and the servo subsystems, including the integration of electromagnetic effects, static pressure characteristics, servo control and mechanical characteristics. According to the air bearing design principle, the geometry of the spindle rotor is designed. The fluid software is used to analyze the influence of the bearing capacity and stiffness on the stability of the spindle. The simulation shows when the air film thickness is 12 μm, the bearing has good load carrying capacity and rigidity. In addition, the influence of motor harmonics on the spindle shaft modes is considered to avoid the resonance of ABS, and to ensure ABS anti-interference capability, proper inertia of ABS is calculated and analyzed. Finally, ABS has a good follow-up effect on the servo control and machining performance through the experimental prototype. The electromechanical coupling design approach for ABS proposed in this paper, can achieve a peak value better than 0.8 μm (surface size: 9 mm × 9 mm) and a surface roughness better than 8 nm in end face turning experiments.

Adsorption of hexavalent chromium onto Bamboo Charcoal grafted by Cu2+-N-aminopropylsilane complexes: Optimization, kinetic, and isotherm studies

Yunhai Wu,Zhu Ming,Shengxin Yang,Yiang Fan,Peng Fang,Haitao Sha,Ligen Cha 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.46 No.-

The adsorption mechanism of Cr(VI) uptake onto Bamboo Charcoal grafted by Cu2+-N-aminopropylsilanecomplexes (BC/Cu-N) was investigated. The properties of BC/Cu-N were characterized using XRD, FTIR,SEM, EDS, potentiometric acid–base titration and electrochemical analysis. Results indicated that theframework integrity of BC was kept aftermodification and the quantity of functional groups on BC/Cu-Nsurface has changed. There existed functional groups on the BC/Cu-N which could consume OH and thepHpzc was found to be 6.20. Moreover, electrochemical analysis showed that new electron transferpathway was imported. Parameters such as pH, initial Cr(VI) concentration, adsorbent dosage andtemperature were optimized using RSM. Analysis of variance of the quadratic model for Cr(VI) wassuitable to predict the adsorption of Cr(VI) (F value = 134.23 and P value < 0.001) with a high correlation(R2 = 0.9921). The results showed that the initial Cr(VI) concentration and the adsorption capacity ofCr(VI) were positively related. Adsorption data of Cr(VI) were better fitted by Sips, Temkin and D-Rmodels with the maximum adsorption capacity of 17.9383 mg/g. In addition, the pseudo second-orderkinetic model was found to be more suitable for the adsorption of Cr(VI).

Parallel Distributed Acceleration Based on MPI and OpenMP Technology

Feng Liu,Haitao Wu,Xiaochun Lu,Xiyang Liu 보안공학연구지원센터 2015 International Journal of Grid and Distributed Comp Vol.8 No.6

In order to speed up data processing in a signal monitoring and evaluation system, we need to use a parallel method. It is obvious that the traditional stand-alone store has no ability to satisfy the performance requirements, and the use of single core CPU is unable to content the severe requirement of speed. Consequently, multi-machine parallel acceleration technique based on MPI (cooperated with multi-core parallel acceleration technique based on OpenMP) can effectively solve all above problems. In this paper, a parallel distributed acceleration framework based on MPI and Open MP technology was given. Experimental tests were carried to verify our proposal. Finally, some suggestions to speed up the data processing was given.

Indoor and Outdoor Scene Classification Method Based on Fourier Transform

Zhijie Zhao,Haitao Wang,Xuesong Jin,Huadong Sun,Qian Wu 보안공학연구지원센터 2014 International Journal of Hybrid Information Techno Vol.7 No.5

Black phosphorus nanosheets‑based effective electrochemical sensor for uric acid detection

Hao Wang,Haitao Wang,Jingjing Yang,Pramitha Yuniar Diah Maulida,Jing Zou,Arramel,Can Wu,Jizhou Jiang 한국탄소학회 2023 Carbon Letters Vol.33 No.7

Black phosphorus (BP) is incorporated in the electrochemical detection of uric acid (UA) to form few layers of BP nanosheets (BPNS)-modified glassy carbon electrodes (BPNS/GCE), investigated by means of ultrasound-assisted liquid-phase exfoliation. We find a significant increase in the peak current magnitude and positive potential shift in the electrochemical response of BPNS/GCE, which may be attributed to the larger specific surface area and good charge transfer ability of BPNS. Further, the electrochemical response of BPNS/GCE is evaluated under different conditions to achieve the optimal conditions. UA detection using differential pulse voltammetry (DPV) shows linear response within the range of 1–1000 μM with a detection limit of 0.33 μM. This work reveals new applications of BP nanomaterials in the electrochemical sensing, thereby promoting further advancement in terms of practical applications of two-dimensional nanomaterials.