Residual Stresses of α-Al2O3/Ni Nano-Composite Coating Prepared by Automatic Brush Plating Technique

Jia Man,Song Zhang,Xiaona Luan,Yuan Hai,Gaoli Cai 한국정밀공학회 2017 International Journal of Precision Engineering and Vol.4 No.1

Brush plating is one of the remanufacturing technologies which have been widely used in engine remanufacturing. In this paper, α-Al2O3/Ni composite coatings were prepared on the inner hole face of the big end of connecting rod by a self-made automatic plating machine. To investigate the effects of process parameters on residual stresses of α-Al2O3/Ni composite coating, a L16(44) orthogonal experiment was designed and operated in which four process parameters (voltage, concentration of α-Al2O3 particles, speed, and distance between anode and workpiece) were selected as factors. ANOVA (analysis of variance) were employed to determine the effects of process parameters on the residual stresses of composite coatings. It was found that speed was the most significant factor for the residual stresses. The optimal process parameters for the desirable residual stresses were obtained, which was proved to be valid by the verification experiments. In addition, single factor experiments were employed to study the main effects of process parameters on composite coatings.

Design, performance analysis, and testing of a GFRP racetrack ring for a high-temperature superconducting motor with a flexible support rotor

Yong Zhou,Feng Xie,Hai-Yuan Jia,Wei Chen 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.10

A conceptual 20 MW high-temperature superconducting (HTS) motor (HTSM) with a novel glass-fiber reinforced plastic (GFRP) racetrack ring in the flexible support rotor was explored in this study. To support the cold mass at operating conditions, the high-strength, lowleakage GFRP racetrack ring was designed as follows. First, conceptual design of the 20 MW HTSM was conducted, and the torque transmitted by the GFRP racetrack rings was obtained through electromagnetic analysis. Second, a GFRP racetrack ring was designed, and its total cross-sectional area was obtained through theoretical analysis. Third, thermal leakage and stress were calculated and examined through theoretical and finite element analyses, respectively. The GFRP racetrack ring with the “D” ring was selected based on the results. The thickness and width of the GFRP ring were set to 16 and 10 mm, respectively, and the thickness of the “D” ring was 3 mm. Then, a full-scaled GFRP ring was fabricated, and its strength and stiffness were tested via room-temperature and low-temperature tensile tests. The average tensile strength and average Young’s modulus of the GFRP ring at room temperature were 1131.5 MPa and 49.9 GPa, respectively. The strength of the GFRP ring at 193.4 K was 1243.9 MPa, and the Young's modulus of the GFRP ring at 141.3 K was 69 GPa. Lastly, a new 200 kW HTS generator was assembled using a scaled rotor with the same structure as the 20 MW HTSM and the original stator of an existing 200 kW generator. The test system was built to evaluate the feasibility of the GFRP ring before manufacturing the 20 MW HTSM. Test results showed that the GFRP ring is feasible, the design method of the GFRP ring is credible. The GFRP ring is suitable for the cold mass support of HTSMs and other low-temperature devices.

Hydrogen-water ameliorates radiation-induced gastrointestinal toxicity via MyD88’s effects on the gut microbiota

Hui-wen Xiao,Yuan Li,Dan Luo,Jia-li Dong,Li-xin Zhou,Shu-yi Zhao,Qi-sheng Zheng,Hai-chao Wang,Ming Cui,Sai-jun Fan 생화학분자생물학회 2018 Experimental and molecular medicine Vol.50 No.-

Although radiation therapy is a cornerstone of modern management of malignancies, various side effects are inevitably linked to abdominal and pelvic cancer after radiotherapy. Radiation-mediated gastrointestinal (GI) toxicity impairs the life quality of cancer survivors and even shortens their lifespan. Hydrogen has been shown to protect against tissue injuries caused by oxidative stress and excessive inflammation, but its effect on radiation-induced intestinal injury was previously unknown. In the present study, we found that oral gavage with hydrogen-water increased the survival rate and body weight of mice exposed to total abdominal irradiation (TAI); oral gavage with hydrogen-water was also associated with an improvement in GI tract function and the epithelial integrity of the small intestine. Mechanistically, microarray analysis revealed that hydrogen-water administration upregulated miR-1968-5p levels, thus resulting in parallel downregulation of MyD88 expression in the small intestine after TAI exposure. Additionally, high-throughput sequencing showed that hydrogen-water oral gavage resulted in retention of the TAI-shifted intestinal bacterial composition in mice. Collectively, our findings suggested that hydrogen-water might be used as a potential therapeutic to alleviate intestinal injury induced by radiotherapy for abdominal and pelvic cancer in preclinical settings.

Single Nucleotide Polymorphisms of the GnRHR Gene Associated with Reproductive Traits of Japanese Flounder (Paralichthys olivaceus)

He, Feng,Wen, Hai-Shen,Li, Ji-Fang,Yu, Da-Hui,Ma, Rui-Qin,Shi, Dan,Mu, Wei-Jie,Zhang, Yuan-Qing,Hu, Jian,Liu, Miao,Han, Wei-Guo,Zhang, Jia-Nan,Wang, Qing-Qing,Yuan, Yu-Ren,Liu, Qun Asian Australasian Association of Animal Productio 2011 Animal Bioscience Vol.24 No.4

Gonadotropin-releasing hormone receptor (GnRHR) gene is expressed at the anterior pituitary gland and plays a key role in gonad development. This study aimed to investigate molecular genetic characteristics of the GnRHR gene and elucidate the effects of single nucleotide polymorphisms (SNPs) of GnRHR gene on sex steroid level in Japanese flounder (Paralichthys olivaceus). We used polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) and sequencing of the GnRHR gene in 75 individuals. We identified three SNPs in the GnRHR gene: P1 locus (C759A and C830T) in the coding region of exon2 which were both linked together and P2 locus (G984T) in the coding region of exon3, which added a new transcript factor (ADR1) and a new methylation site (CG). Only C830T of P1 leads to amino acid changes Thr266Ile. Statistical analysis showed that P1 was significantly associated with $17{\beta}$-estradiol ($E_2$) level (p<0.01) and gonadosomatic index (GSI) (p<0.05). Individuals with genotype BB of P1 had significantly higher serum $E_2$ levels (p<0.01) and GSI (p<0.05) than those of genotype AA or AB. Another SNP, P2, synonymous mutation, was significantly associated with GSI (p<0.05). Individuals with genotype AB of P2 had significantly higher GSI (p<0.05) than that of genotype AA. In addition, there was a significant association between one diplotype based on three SNPs and reproductive traits. The genetic effects for both serum $E_2$ level and GSI of diplotype D4 were super diplotypes (p<0.05). These results suggest that the SNPs in Japanese Flounder GnRHR are associated with $E_2$ level and GSI.

Overtopping Failure Process and Core Wall Fracture Mechanism of a New Concrete Core Wall Dam

You-ming Zuo,Jia-wen Zhou,Hai-bo Li,Jie-yuan Zhang,Chang Tan,Xiaodong Wang,Yu-shan Wang,Yue Zhou 대한토목학회 2024 KSCE Journal of Civil Engineering Vol.28 No.5

Concrete core wall dams have emerged as a cost-effective alternative to the reconstruction of old dams. However, the flooding mechanism and flood line of these dams differ significantly from traditional earth and rockfill dams due to the concrete core wall functioning as reinforcement. This study presents model tests that simulate the overtopping failure of earth and rockfill dams with concrete core walls of various thicknesses. The hydrologic curve and two-dimensional evolution of the breach are analyzed, and mechanical analysis examines the relationship between core wall thickness and free face during core wall failure. Results indicate that the presence of the concrete core wall shifts the overtopping failure mode to the scour pit failure mode. The scour pit failure mode occurs when upstream water scours the downstream core wall to form scour holes and free faces. Continuous scouring increases the depth of the free face, ultimately causing the moment between the two sides of the core wall to exceed the bending moment of the core wall, resulting in fracture. The study provides a theoretical basis for the design of core walls for this new type of dam.

Prognosis of Eight Chinese Cases of Primary Vaginal Yolk Sac Tumor with a Review of the Literature

Tang, Qiong-Lan,Jiang, Xue-Feng,Yuan, Xiao-Ping,Liu, Yong,Zhang, Lin,Tang, Xiao-Feng,Zhou, Jia-Jia,Li, Hai-Gang,Fang, Jian-Pei,Xue, Lin Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.21

Background: Primary vaginal yolk sac tumor is a rare malignancy in the pediatric population, and a diagnostic challenge and appropriate initial treatment remains unsolved. The aim of this study was to investigate the clinicopathologic features, treatment and prognosis of this tumor. Materials and Methods: Eight cases of primary vaginal yolk sac tumor were reported with a literature review. Results: There were 4 pure yolk sac tumor cases and four mixed germ cell tumors containing yolk sac tumor element, including two cases with embryonal carcinoma and two cases with embryonal carcinoma and dysgerminoma. Partial vaginectomy was performed in four cases and all patients received chemotherapy. 85 cases in literatures were reviewed and 9 cases were misdiagnosed. Follow-up data was available in 77 cases and 5-year overall survival rate was 87.6%. 5-year survival rate of biopsy with chemotherapy, conservative surgery with chemotherapy and radical surgery with chemotherapy was 91.1%, 100% and 28.6%, respectively (p<0.001). Compared to cases without relapse or metastasis after initial treatment, patients with relapse or metastasis had a shorter overall survival (35.6% vs 96.6%, p<0.001). Conclusions: Mixed germ cell tumor containing yolk sac tumor element was not uncommon and partial vaginectomy may be a good choice for primary vaginal mixed yolk sac tumor type to eradicate local tumor cells and provide complete information for pathological diagnosis and postoperative adjuvant therapy.