Reflectometry based Cable Insulation Aging Diagnosis and Prognosis

Author(s):  
Xuan Wang ◽  
Enhui Liu ◽  
Bin Zhang
2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Xuan Wang

Cables in power generation and delivery are under high thermal stress cycles. Such high temperature can lead to cable insulation degradation, which will reduce the projected lifetime. Existing methods mainly focus on cable fault detection or insulation degradation mechanism. There is no existing tools for diagnosing the insulation degradation level and predicting the remaining useful life of the cable. The goal of my Ph.D. research is to develop reflectometry and data based approaches to monitor the health status of cables. The research will be conducted in three steps: (1) development of reflectometry based method to monitor the cable insulation degradation; (2) feature extraction and cable insulation degradation dynamic modeling based on the accelerated aging test data; (3) development of risksenstive particle filtering based fault diagnosis and prognosis algorithms for cable degradation; and (4) verification and validation the proposed solution with new experiment data and comparison with existing approaches.


2021 ◽  
Vol 261 ◽  
pp. 02053
Author(s):  
Jin Ming Guo ◽  
Fei Feng Wang

In order to further study the effect of different degree of acidity and alkalinity on cable insulation aging, the aging condition of cable insulation was compared and analyzed under different pH values. The samples of cable insulation material slice and short cable were carried out the accelerated aging test, which were placed in the conditions of different pH values. And then the test results of micro morphology and electrical properties between the different samples were compared and analyzed after aging. According to the test results in this paper, the micro morphology of the cable insulation material slice would change differently under the aging conditions of different acidity and alkalinity, which indicated that the degree of oxidation degradation of insulation material aging was different from the different acidity and alkalinity conditions. In addition, both acid or alkaline environment would accelerate the aging of cable insulation and reduce the service life of cable, while strong acid and strong alkaline environment are more conducive to the formation of interpenetrating water tree in cable insulation material and cause the operation accident of power cable. Furthermore, the test results of electrical properties of short cable samples after aging showed that the aging degree of short cable samples was more serious in alkaline environment, and the decline of electrical properties was faster.


Author(s):  
F. Al-Bagdadi ◽  
D. Hoyt ◽  
P. Karns ◽  
G. Martin ◽  
M. Memon ◽  
...  

The most frequently occuring abnormality of the male genital system in mammals is the failure of one or both testes to descend into the scrotum. The reasons for abdominal or inguinal retention of testes could be anatomic malformation, faulty development or hormone imbalance.Cryptorchidism has been associated with either greatly reduced or absent spermatogenesis (Kaueakami et al, 1984), and being a source of neoplasia. According to Stick (1980), germinal carcinoma cells have been believed to be the cause of teratomas in equine cryptorchid testicles. Neoplasia has been reported in descended testes of unilateral cryptorchid patients (Martin et al, 1981).No distinction has been made in relating the problem of cryptorchid testes to inguinal or abdominal retention. The purpose of this study is to record the morphological differences between inguinal and abdominal cryptorchid testes as an aid in diagnosis and prognosis.


2020 ◽  
Vol 48 (5) ◽  
pp. 2295-2305
Author(s):  
Jiawei Zhang ◽  
Dandan Li ◽  
Rui Zhang ◽  
Peng Gao ◽  
Rongxue Peng ◽  
...  

The role of miR-21 in the pathogenesis of various liver diseases, together with the possibility of detecting microRNA in the circulation, makes miR-21 a potential biomarker for noninvasive detection. In this review, we summarize the potential utility of extracellular miR-21 in the clinical management of hepatic disease patients and compared it with the current clinical practice. MiR-21 shows screening and prognostic value for liver cancer. In liver cirrhosis, miR-21 may serve as a biomarker for the differentiating diagnosis and prognosis. MiR-21 is also a potential biomarker for the severity of hepatitis. We elucidate the disease condition under which miR-21 testing can reach the expected performance. Though miR-21 is a key regulator of liver diseases, microRNAs coordinate with each other in the complex regulatory network. As a result, the performance of miR-21 is better when combined with other microRNAs or classical biomarkers under certain clinical circumstances.


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