Grouting to Prevent Sulfate Corrosion on Coal Mine Shaft

Gang-Gang Xu,Shuan-Cheng Gu,Xiao-Dong Wang,Hai Wang,Shi-Bin Zhu 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.11

In the area of high sulfate concentration in China, the problem of sulfate corrosion in coal mine shaft is increasingly prominent. Currently, shaft repair methods are limited to diversion, interception, and backwall grouting. However, after conventional cement stabilization, shafts still must contend with poor durability and weak resistance to sulfate corrosion. To solve these problems, this study combined theoretical research, laboratory tests, and field tests to reveal the corrosion mechanism of shafts, explored novel anti-sulfate corrosion grout, and built a model for the migration of sulfate ions (SO42−) in strata and shafts. According to the results of this study, shaft corrosion was a process of continuous penetration towards the concrete interior following a cycle of concrete compaction, expansion, and cracking. Laboratory tests show that the specimens of ordinary Portland cement mortar with 20 – 30% fly ash not only have good long-term strength, but also have a significantly improved resistance capacity to sulfate solution. Based on the laboratory test results, the HSR42.5 mixed with 20% fly ash was used for wall grouting, and the water-cement ratio of the slurry was 1:1. After wall grouting, the water inflow was effectively controlled in the grouting area in the main shaft, auxiliary shaft, and air shaft, reducing from 18.5 m3/h, 20.9 m3/h, and 10.0 m3/h to 3.5 m3/h, 4.6 m3/h, and 3.2 m3/h, respectively. Moreover, after nearly three years of continuous monitoring, the water inflow did not show any significant increase in the shafts. Based on the migration law of SO42− in concrete, a shaft geological model and a salt solution migration model after grouting reinforcement under sulfate corrosion conditions were constructed. In addition, the analysis of the migration law of sulfate ion in the shaft and grouting reinforcement formation revealed that the service period of the grouting shaft can be extended for approximately 6 – 8 years.

Fibulin-5 is a Prognostic Marker that Contributes to Proliferation and Invasion of Human Glioma Cells

Sheng, Xu-Dong,Chen, Hu,Wang, Hui,Ding, Zhi-Bin,Xu, Gang-Zhu,Zhang, Jun-Feng,Lu, Wen-Chao,Wu, Tao,Zhao, Ling Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.2

Fibulin-5 has recently been considered as a potential tumor suppressor in human cancers. Several studies have shown that it is down-regulated in a variety of tumor types and inhibits tumor growth and metastasis. This study was aimed to investigate the clinical significance of fibulin-5 in glioma and its role in cell proliferation and invasion. We found that the expression of fibulin-5 in glioma tissues was significantly lower than those in normal brain (NB) tissues. Negative expression was significantly correlated with advanced clinical stage (grade III+IV). Furthermore, Fibulin-5 negative expression was correlated with a shorter overall survival of glioma patients. Multivariate Cox repression analysis indicated that fibulin-5 was an independent factor for predicting overall survival of glioma patients. Overexpression obviously inhibited cell proliferation in U251 and U87 cells. Furthermore, it significantly reduced the number of migrating and invading glioma cells. In conclusion, impaired expression of fibulin-5 is correlated with the advanced tumor stage in glioma. Otherwise, Fibulin-5 is an independent prognostic marker for predicting overall survival of glioma patients. Mechanistically, it may function as a tumor suppressor via inhibiting cell proliferation and invasion in gliomas.

Comorbidity Relationship to Outcome of Radical Cystectomy in Chinese: a Single Institution Study with the ACE-27 Comorbidity Index

Xuan, Zhu,Zhong, Zhao-Hui,Zhang, Xuan-Zhi,Zhang, Lei,Zhao, Xiao-Kun,Lv, Chen,Xu, Ran,Ren, Wei-Gang,Li, Song-Chao Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.3

To determine the relationship between comorbidity and outcome after radical cystectomy in Chinese patients by using the Adult Comorbidity Evaluation (ACE)-27 index. Two-hundred-and-forty-six patients treated with radical cystectomy at the Second Xiangya Hospital of Central South University, Hunan Province, China between 2000 and 2010 were retrospectively analyzed. Medical records were reviewed for age, gender, delayed time of radical cystectomy, urinary diversion type, pelvic lymphadenectomy status, TNM stage, and pathological grade. Comorbidity information was assessed by the ACE-27 index. The outcome measurement was overall survival. Univariate and multivariate Cox proportional hazards regression analyses were used to determine the association between comorbidity and outcome. The study population consisted of 215 (87.40%) males and 31 (12.60%) females with a mean age of $62{\pm}11$ years. Median duration of follow-up was $47{\pm}31$ months. A total of 151 (61.38%) patents died during follow-up. Of those, 118 (47.97%) had at least one comorbidity. According to the ACE-27 scores, 128 (52.03%) patients had no comorbidity, 79 (32.11%) had mild, 33 (13.41%) had moderate, and 6 (2.45%) had severe comorbidities. Multivariate analysis indicated that moderate (p=0.002) and severe (p<0.001) comorbidity was significantly associated with decreased overall survival. In addition, age ${\geq}70$ years (p=0.002), delayed time of radical cystectomy >12 weeks (p=0.044), pelvic lymphadenectomy status (p=0.014), and TNM stage >T3 (p<0.001) were determined to be independent risk factors of overall survival. Increasing severity of comorbidity statistically correlated with decreased overall survival after radical cystectomy.

Bending ratcheting behavior of pressurized straight Z2CND18.12N stainless steel pipe

Lei Wang,Gang Chen,Jianbei Zhu,Xiuhu Sun,Yunhui Mei,Xiang Ling,Xu Chen 국제구조공학회 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.52 No.6

The ratcheting effect greatly challenges the design of piping components. With the assistance of the quasi-three point bending apparatus, ratcheting and the ratcheting boundary of pressurized straight Z2CND18.12N stainless steel pipe under bending loading and vertical displacement control were studiedexperimentally. The characteristics of progressive inelastic deformation in axial and hoop directions of the Z2CND18.12N stainless steel pipes were investigated. The experiment results show that the ratcheting strainoccurs mainly in the hoop direction while there is less ratcheting strain in the axial direction. Thecharacteristics of the bending ratcheting behavior of the pressure pipes were derived and compared under load control and displacement control, respectively. The results show that the cyclic bending loading and the internal pressure affect the ratcheting behavior of the pressurized straight pipe significantly under loadcontrol. In the meantime, the ratcheting characteristics are also highly associated with the cyclicdisplacement and the internal pressure under displacement control. All these factors affect not only the saturation of the ratcheting strain but the ratcheting strain rate. A series of multi-step bending ratcheting experiments were conducted under both control modes. It was found that the hardening effect of Z2CND18.12N stainless steel pipe under previous cyclic loadings no matter with high or low displacement amplitudes is significant, and the prior loading histories greatly retard the ratcheting strain and its rate under subsequent loadings. Finally, the ratcheting boundaries of the pressurized straight Z2CND18.12N stainless steel pipe were determined and compared based on KTA/ASME, RCC-MR and the experimental results.

A Test Suite Reduction Method based on Test Requirement Partition

Wan Yongbing,Xu Zhongwei,Yu Gang,Zhu YuJun 보안공학연구지원센터(IJGDC) 2013 International Journal of Grid and Distributed Comp Vol.6 No.4

Biochar Can Mitigate Farmland Global Warming Potential and Remediate Pops Polluted Soil

Zubin Xie,Yanping Xu,Georg Cadisch,James Amonette,Jianguo Zhu,Gang Liu 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Bending ratcheting behavior of pressurized straight Z2CND18.12N stainless steel pipe

Wang, Lei,Chen, Gang,Zhu, Jianbei,Sun, Xiuhu,Mei, Yunhui,Ling, Xiang,Chen, Xu Techno-Press 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.52 No.6

The ratcheting effect greatly challenges the design of piping components. With the assistance of the quasi-three point bending apparatus, ratcheting and the ratcheting boundary of pressurized straight Z2CND18.12N stainless steel pipe under bending loading and vertical displacement control were studied experimentally. The characteristics of progressive inelastic deformation in axial and hoop directions of the Z2CND18.12N stainless steel pipes were investigated. The experiment results show that the ratcheting strain occurs mainly in the hoop direction while there is less ratcheting strain in the axial direction. The characteristics of the bending ratcheting behavior of the pressure pipes were derived and compared under load control and displacement control, respectively. The results show that the cyclic bending loading and the internal pressure affect the ratcheting behavior of the pressurized straight pipe significantly under load control. In the meantime, the ratcheting characteristics are also highly associated with the cyclic displacement and the internal pressure under displacement control. All these factors affect not only the saturation of the ratcheting strain but the ratcheting strain rate. A series of multi-step bending ratcheting experiments were conducted under both control modes. It was found that the hardening effect of Z2CND18.12N stainless steel pipe under previous cyclic loadings no matter with high or low displacement amplitudes is significant, and the prior loading histories greatly retard the ratcheting strain and its rate under subsequent loadings. Finally, the ratcheting boundaries of the pressurized straight Z2CND18.12N stainless steel pipe were determined and compared based on KTA/ASME, RCC-MR and the experimental results.

Microstructure evolution and effect on deuterium retention in oxide dispersion strengthened tungsten during He⁺ irradiation

Ding, Xiao-Yu,Xu, Qiu,Zhu, Xiao-yong,Luo, Lai-Ma,Huang, Jian-Jun,Yu, Bin,Gao, Xiang,Li, Jian-Gang,Wu, Yu-Cheng Korean Nuclear Society 2020 Nuclear Engineering and Technology Vol.52 No.12

Oxide dispersion-strengthened materials W-1wt%Pr₂O₃ and W-1wt%La₂O₃ were synthesized by wet chemical method and spark plasma sintering. The field emission scanning electron microscopy (FE-SEM) analysis, XRD and Vickers microhardness measurements were conducted to characterize the samples. The irradiations were carried out with a 5 keV helium ion beam to fluences up to 5.0 × 10²¹ ions/m² under 600 ℃ using the low-energy ion irradiation system. Transmission electron microscopy (TEM) study was performed to investigate the microstructural evolution in W-1wt%Pr₂O₃ and W-1wt%La₂O₃. At 1.0 × 10²⁰ He⁺/m², the average loops size of the W-1wt%Pr₂O₃ was 4.3 nm, much lower than W-1wt% La₂O₃ of 8.5 nm. However, helium bubbles were not observed throughout in both doped W materials. The effects of pre-irradiation with 1.0 × 10²¹ He⁺/m² on trapping of injected deuterium in doped W was studied by thermal desorption spectrometry (TDS) technique using quadrupole mass spectrometer. Compared with the samples without He⁺ pre-irradiation, deuterium (D) retention of doped W materials increased after He⁺ irradiation, whose retention was unsaturated at the damage level of 1.0 × 10²²D₂⁺/m². The present results implied that irradiation effect of He⁺ ions must be taken into account to evaluate the deuterium retention in fusion material applications.

Study on the Transmission Error Prediction for a Spur Gear Pair

Qi Zhang(장기),Jing Zhang(장정),Zhong Gang Zhu(주충강),Zhen Rong Wang(왕진영),Zhe-zhu Xu(허철수),Sung Ki Lyu(류성기) Korean Society for Precision Engineering 2016 한국정밀공학회지 Vol.33 No.2

Nowadays, lower gear vibration and noise are necessary for drivers in automotive gearbox, which means that transmission gearbox should be optimized to avoid noise annoyance and fatigue before quantity production. Transmission error (T.E.) is the excitation factor that affects the noise level known as gear whine, and is also the dominant source of noise in the gear transmission system. In this paper, the research background, the definition of T.E. and gear micro-modification were firstly presented, and then different transmission errors of loaded torques for the spur gear pair were studied and compared by a commercial software. It was determined that the optimum gear micro-modification could be applied to optimize the transmission error of the loaded gear pair. In the future, a transmission test rig which is introduced in this paper is about to be used to study the T.E. after gear micro-geometry modification. And finally, the optimized modification can be verified by B&K testing equipment in the semi-anechoic room later.

Phase II trial of VEGFR2 inhibitor apatinib for metastatic sarcoma: focus on efficacy and safety

Zhichao Liao,Feng Li,Chao Zhang,Lei Zhu,Yehui Shi,Gang Zhao,Xu Bai,Shafat Hassan,Xinyue Liu,Ting Li,Peipei Xing,Jun Zhao,Jin Zhang,Ruwei Xing,Sheng Teng,Yun Yang,Kexin Chen,Jilong Yang 생화학분자생물학회 2019 Experimental and molecular medicine Vol.51 No.-

Apatinib (YN968D1) is a novel tyrosine kinase inhibitor targeting vascular endothelial growth factor receptor 2 (VEGFR- 2). We conducted a single-arm, nonrandomized phase II study (NCT03121846) to assess the efficacy and safety of apatinib in patients with stage IV sarcoma. We recruited 64 patients with stage IV sarcoma who had failed chemotherapy. The primary endpoint was progression-free survival (PFS), and the secondary endpoints were progression-free survival rate (PFR), objective response rate (ORR), and disease control rate (DCR) at week 12. Treatment-related adverse effects (AEs) were evaluated. Fifty-nine patients were assessed for efficacy and 64 patients for AEs. The median PFS was 7.93 months. At 12 weeks, the PFR was 74%, the ORR was 16.95% (10/59), and the DCR was 86.44% (51/59). The final ORR was 15.25% (9/59) and the DCR was 57.63% (34/59). Notably, 22 patients (34.38%) who developed hypertension, hand-foot-skin reaction, or proteinuria had significantly longer OS than those without these AEs (18.20 vs. 10.73 months; P = 0.002). We conclude that apatinib is effective and well tolerated in patients with advanced sarcoma. The development of hypertension, hand-foot-skin reaction, or proteinuria may indicate a favorable prognosis, representing a novel finding in sarcoma patients.