Effect of specific functional groups on oil adhesion from mica substrate: Implications for low salinity effect

Jiazhong Wu,Fanghui Liu,Hui Yang,Shijing Xu,Quan Xie,Minghui Zhang,TING CHEN,Guangxin Hu,Jinben Wang 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.56 No.-

Low salinity effect has been in the center of attention as a cost-effective and environmentally friendlytechnique. Wettability alteration of the oil/brine/mica system appears to be the identified mechanism(s)to trigger the low salinity effect. While the effect of water chemistry and minerology on the wettability ofthe system has been extensively investigated, few studies have investigated the effect of specific functiongroups from crude oil on the system wettability, limiting the understanding of how specific functionalgroup contributes to the wettability. We thus experimentally measured the adhesion forces betweenmica surfaces and functional groups (e.g., C6H5–, CH3–, COOH–, and NH2–) in the presence of differentaqueous ionic solutions using chemical force microscopy (CFM). Moreover, to understand thecontribution of the structural force, the traditional Derjaguin–Landau–Verwey–Overbeek (DLVO) theorywas extended (denoted as EDLVO) tofit the force profiles using a Gauss model. Our results showed thatthe adhesion force between mica and functional groups in a decreasing order was –NH2> –COOH> –CH3> –C6H5. We also found that while DLVO forces strongly affected the tip-surface contact due to theinteractions among oil/brine/mica interfaces, the structural forces also played an important role in adistance of 1–20 nm due to the presence of H-bonds between COOH-terminated or NH2-terminated tipand mica surface. We therefore conclude that the structural force largely contributes to the adhesionforce due to the hydrophilicity or polarity of functional groups, and nucleophilic property (such as phenylgroup). Our results suggest that the polarity of the crude oil needs to be considered to screen a candidatereservoir for low salinity waterflooding projects.

A Conflict Detection Method Based on Constraint Satisfaction in Collaborative Design

Yang, Kangkang,Wu, Shijing,Zhao, Wenqiang,Zhou, Lu Korean Institute of Information Scientists and Eng 2015 Journal of Computing Science and Engineering Vol.9 No.2

Hierarchical constraints and constraint satisfaction were analyzed in order to solve the problem of conflict detection in collaborative design. The constraints were divided into two sets: one set consisted of known constraints and the other of unknown constraints. The constraints of the two sets were detected with corresponding methods. The set of the known constraints was detected using an interval propagation algorithm, a back propagation (BP) neural network was proposed to detect the set with the unknown constraints. An immune algorithm (IA) was utilized to optimize the weights and the thresholds of the BP neural network, and the steps were designed for the optimization process. The results of the simulation indicated that the BP neural network that was optimized by IA has a better performance in terms of convergent speed and global searching ability than a genetic algorithm. The constraints were described using the eXtensible Markup Language (XML) for computers to be able to automatically recognize and establish the constraint network. The implementation of the conflict detection system was designed based on constraint satisfaction. A wind planetary gear train is taken as an example of collaborative design with a conflict detection system.

A Conflict Detection Method Based on Constraint Satisfaction in Collaborative Design

Kangkang Yang,Shijing Wu,Wenqiang Zhao,Lu Zhou 한국정보과학회 2015 Journal of Computing Science and Engineering Vol.9 No.2

Hierarchical constraints and constraint satisfaction were analyzed in order to solve the problem of conflict detection in collaborative design. The constraints were divided into two sets: one set consisted of known constraints and the other of unknown constraints. The constraints of the two sets were detected with corresponding methods. The set of the known constraints was detected using an interval propagation algorithm, a back propagation (BP) neural network was proposed to detect the set with the unknown constraints. An immune algorithm (IA) was utilized to optimize the weights and the thresholds of the BP neural network, and the steps were designed for the optimization process. The results of the simulation indicated that the BP neural network that was optimized by IA has a better performance in terms of convergent speed and global searching ability than a genetic algorithm. The constraints were described using the eXtensible Markup Language (XML) for computers to be able to automatically recognize and establish the constraint network. The implementation of the conflict detection system was designed based on constraint satisfaction. A wind planetary gear train is taken as an example of collaborative design with a conflict detection system.

Network Traffic Anomaly Detection Based on N-ARMA Model

Pingping Gu,Shijing Zhang,Zhimin Huang,Qingfeng Wu 보안공학연구지원센터 2016 International Journal of Database Theory and Appli Vol.9 No.11

With the rapid development of the Internet and the continuous expanding of the data network, little potential anomaly can seriously affect the normal operation of the network, and even lead to huge economic losses. In order to be more accurate and efficient in the traffic detection, in this paper, we propose an N-ARMA based traffic anomaly detection model. We also conduct extensive experiments to verify the higher accurate ratio and recall ratio of our model by comparing with other traffic anomaly detection methods.

Novel frictional algorithm implementing angular increment for two-dimensional frictional systems

Deng Zhao,Shijing Wu,Qiaoquan Li,Xiaofeng Li,Xiaoyong Li,Xiaosun Wang 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.7

This study proposes a new frictional algorithm that implements angular increment. The proposed algorithm is used to solve the numerical solutions of dynamic problems in two-dimensional frictional systems. It can accurately obtain the motion responses of a lumped mass under time-varying external forces, and it can compensate for the shortcomings of the numerical frictional algorithm that implements a time step. Specifically, the proposed algorithm 1) overcomes the difficulties encountered when the angles between resultant tangential forces and slip motion are infinitely close, 2) provides accurate solutions for two-dimensional systems under fierce planar motions, and 3) calculates the responses of the mass within a reasonable period. We compare the computation accuracy, efficiency, and robustness of the proposed frictional algorithm and the previous frictional algorithm [1] through several representative scenarios. We reveal that the proposed algorithm has superior computation accuracy, efficiency, and robustness for two-dimensional frictional problems involving slip/stick transitions and sharp bending.

Research on load sharing performance of wind turbine gearbox involving multiple-errors and tooth crack

Fuqi Xie,Yunyun Sun,Shijing Wu,Qiang Zhang,Xiaoyong Li 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.9

The current research on wind turbine gearboxes (WTG) considering multiplefactors influence mainly focuses on dynamic response. However, load sharing performance (LSP) is also extremely important for gear transmission system reliability. In this paper, considering the comprehensive effects of manufacturing errors, assembly errors, clearance floating between stages, mesh stiffness and time-varying load, a coupled translation-torsion dynamic model for WTG was developed to study the LSP. Based on the amplitude variations of timevarying mesh stiffness caused by tooth crack, an approach is provided to introduce the tooth crack into the dynamic model. The results indicate the LSP is mostly sensitive to multiple-errors and severe tooth crack, followed by the time-varying load. The LSP of a system is periodically affected by tooth crack, and the fluctuation ranges increase with the crack growth. Furthermore, the crack of sun gear has greater influence on LSP than that of planet and ring gear.

A numerical and effective method for the contact stress calculation of elliptical partial slip

Xiaoyong Li,Liang Liang,Shijing Wu 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.2

A general elliptical Hertzian contact, such as a ball rolling in a non-conforming groove or two non-orthogonal cylinders, is a universalphenomenon in engineering. A partial elliptical contact is formed by contact bodies under a normal force and a transverse force that isinsufficient to cause complete sliding. A computational model based on the semi-analytical method is established to calculate the vonMises stress distribution. Furthermore, a parametric study on factors influencing the location of the maximum von Mises stress point,such as the coefficient of friction and stick zone ratio, is conducted. Results show that the location of the maximum von Mises stresspoint depends on the coefficient of friction f and stick zone ratio c. The von Mises stress increases significantly with the increasing coefficientof friction f. Moreover, the maximum von Mises stress point tends to occur at a subsurface when the stick ratio c increases.

Role of Amine-Cavity Interactions in Determining the Structure and Mechanical Properties of the Ferroelectric Hybrid Perovskite [NH₃NH₂]Zn(HCOO)₃

Kieslich, Gregor,Forse, Alexander C.,Sun, Shijing,Butler, Keith T.,Kumagai, Shohei,Wu, Yue,Warren, Mark R.,Walsh, Aron,Grey, Clare P.,Cheetham, Anthony K. American Chemical Society 2016 Chemistry of materials Vol.28 No.1

<P>Dense formate frameworks with a perovsldte-like architecture exhibit multiferroic behavior and tunable mechanical properties. In such materials, interactions between the protonated amine and the metal formate cavity have a large impact on the mechanical properties. We use complementary single-crystal X-ray diffraction and H-1 solid state nuclear magnetic resonance spectroscopy to investigate amine cavity interactions in [NH3NH2]Zn(HCOO)(3). The results suggest that these interactions can be described as salt bridges similar to those in proteins and artificially synthesized helical polymers, where ionic interactions and hydrogen bonds are present at the same time. Nanoindentation and high-pressure single-crystal X-ray diffraction were used to study the mechanical properties of [NH3NH2]Zn(HCOO)(3), yielding elastic moduli of E-001 = 26.5 GPa and E-110 = 24.6 GPa and a bulk modulus of K = 19 GPa. The mechanical properties suggest that, despite the relatively low packing density of [NH3NH2]Zn(HCOO)(3), the amine cavity interactions strengthen the framework significantly in comparison with related materials.</P>