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Design of the energy-balanced wireless sensor networks for 3D seismic exploration
Xiaohua Zhou,Jianbin Zheng,Xinkai Meng,Guanghui Sun,Ruyun Tian 한국통신학회 2023 ICT Express Vol.9 No.3
Wireless Sensor Networks for 3D Seismic Exploration are large-scale and long-term networks to ensure high resolution. Energy balance is essential to avoid interruption of the whole network. In this paper, the hybrid wireless network architecture is designed for low-power monitoring system. An energy-balanced clustering method is developed to prolong network lifetime. The partial energy factor is introduced to optimize scheduling of cluster head nodes. An improved ant colony algorithm for energy-efficient clustering and routing network (IACA-EECR) is proposed to find optimal path. The results show the proposed architecture outperforms the existing platform. Extensive tests validate energy efficiency and network performance.
Xiaohua Lu,Jianguo Lin,Changgao Wang,Xin Du,Jun Cai 한국식품과학회 2016 Food Science and Biotechnology Vol.25 No.5
The purification and characterization of the extracellular polygalacturonase from Zygoascus hellenicus V25 submerged culture using orange peel waste were investigated. This polygalacturonase, with a molecular weight of 75.28 kDa, was purified to 16.89 purification fold with a recovery of 18.46% and specific activity of 2469.77 U/mg protein by ammonium sulfate precipitation, DEAE cellulose chromatography, and Sephadex G-100 gel filtration. The enzyme exhibited maximum activity at 60oC and pH 5.0 and was stable over a wide range of pH levels (3.0-11.0). Moreover, enzyme activity was enhanced by Cu2+ and cysteine, whereas it was strongly inhibited by Hg2+. The extent of enzymatic hydrolysis was negatively correlated with the degree of pectin esterification. Km and Vmax values of the polygalacturonase were 5.44 mg/mL and 61.73 μmol/(min·mg), respectively. The polygalacturonase was applied in the juice clarification of four fruits, and results showed that the percentage transmittance at 660 nm increased by 3.51, 4.36, 8.04, and 12.2%.
The Investigation of Rock Indentation Simulation Based on Discrete Element Method
Xiaohua Zhu,Weiji Liu,Xianqun He 대한토목학회 2017 KSCE JOURNAL OF CIVIL ENGINEERING Vol.21 No.4
Rock indentation is widely encountered in rock engineering, such as oil & gas drilling process. The rock indentation represents the fundamental process for mechanical rock breaking. Therefore, it is necessary to research the failure mechanism during the rock indentation process. For this purpose, the Uniaxial Compressive Strength (UCS) and Brazilian Tensile Strength (BTS) tests are performed to calibrate the relations between micro-properties and macro-properties of the rock specimens. The rock indentation process and crack propagation with the effects of lateral pressure, hydraulic pressure, ledge, wedge angle and joint are researched by PFC2D in this paper. The results show that: with the indenter penetrating into rock, the sub-vertical crack is formed from the damaged zone and it will extend to bottom edge of the rock at last; the initiation and propagation of the sub-vertical crack is mostly driven by the tensile contact force. The development of sub-vertical crack and damaged zone are restrained with increasing lateral pressure, the lateral pressure increases led to an increase in the critical penetration depth and the size of the damaged zone decreases and its shape flattens with the lateral pressure increasing. On the contrary, the development of sub-vertical crack and damaged zone are promoted with increasing hydraulic pressure. With the wedge angle increases the size of crushed zone underneath the indenter increases, it promotes the formation of sub-vertical crack; larger wedge angle causes a larger indentation force. The existence of a ledge leads to crack initiation and propagation towards the free surface and the presence of the joint also promotes crack initiation and propagation towards the joint; when the crack propagates to the joint, the crack will no longer propagate towards the intact rock mass but along the joint.
Mechanical plugging—solid expandable tubular refracturing technology
Xiaohua Zhu,Feilong Cheng,Changshuai Shi,Kailin Chen 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.6
To solve the three major problems of low production, low efficiency and low permeability of oil fields, it is necessary to develop new tight oil layers or shale oil outside the original perforated section in the well that has been perforated. The key to the success of repeated fracturing operations is the ability to block the original perforation of the well. At present, with tubing fracturing construction, volume fracturing of the target reservoir cannot be achieved due to limited displacement, and the effect of reservoir transformation is not obvious, affecting the productivity of the old well. Based on the above problems, this paper proposes a new blocking method suitable for fracturing wells - solid expansdable tubular (SET) plugging. In this paper, it established SET-expansion cone-casing-rubber ring 2D dynamic model which considers the friction, and contact, to analyze the effect of compression and length of rubber ring and the constraint condition of SET on sealing performance; laboratory experiments were carried out and data on driving force, sealing capacity and suspension force were obtained. The results show that optimizing the parameters of expansion cone structure can effectively reduce the residual stress of SET and driving force after expansion; the construction method of SET and the parameters of rubber ring are the main factors that affect the suspension sealing ability, and paper proposes an effective solution; in addition, experiment results show that the SET meets the requirements of fracturing construction with internal pressure greater than 60 MPa and suspension force greater than 600 kN after expansion, and can be used to seal the well body structure of refracturing wells with fewer perforations and shorter distances, and the diameter can be guaranteed to reach 112 mm. The research results provide new ideas and solutions for repeated pressure wells and high-pressure plugging.
Design and analysis of sealed suspension module based on solid expandable tubular repair technology
Xiaohua Zhu,Feilong Cheng,Changshuai Shi,Jia’nan Li,Kailin Chen 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.2
The ability of sealing suspension of solid expandable tubular (SET) is one of the important factors that determine whether pipe can expand normally and serve. To solve the problem that the SET deviates from the original position (causing for the failure to repair of leakage well) due to the insufficient suspension force after expansion, this paper establishes the two-dimensional coupling model of SET-rubber ring-expansion cone-casing based on laboratory experiment parameters, designs the parameters of the sealed suspension rubber ring and conducts simulation. The results show that when the compression amount of the rubber ring is designed to be 47 %-58 % of the rubber thickness, the SET has excellent sealing ability after expansion and can meet the requirements of suspension force; too much compression will affect the service life of the rubber ring. When the length of the rubber ring is 50 mm-110 mm, the driving force and contact pressure during expansion are suitable; the rubber ring spacing is designed to be 110 mm, which avoids interference after rubber compression and saves material. In addition, the vulcanizing bonding strength of the rubber ring should be greater than 120 kN to avoid peeling off due to the failure of the rubber ring and SET bonding. The research results of this paper provide a theoretical basis for the design of sealing suspension module of SET repair technology.