Lifetime Prediction and Aging Behaviors of Nitrile Butadiene Rubber under Operating Environment of Transformer

Yi-hua Qian,Hong-zhao Xiao,Ming-hao Nie,Yao-hong Zhao,Yun-bai Luo,Shu-ling Gong 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.2

Based on the actual operating environment of transformer, the aging tests of nitrile butadiene rubber (NBR) were conducted systematically under four conditions: in air, in transform oil, under compression in air and under compression in transform oil to studythe effect of high temperature, transform oil and compression stress simultaneously on the thermal aging behaviors of nitrile butadiene rubber and predict the lifetime. The effects of liquid media and compression stress simultaneously on the thermal aging behaviors of nitrile butadiene rubber were studied by using characterization methods such as IR spectrosc-opy, thermogravimetric measurements, Differential Scanning Calorimetry (DSC) measurements and mechanical property measurements. The changes in physical properties during the aging process were analyzed and compared. Different aging conditions yielded materials with different properties. Aging at 70°C under compression stress in oil, the change in elongation at break was lower than that aging in oil, but larger than that aging under compression in air. The compression set or elongation at break as evaluation indexes, 50% as critical value, the lifetime of NBR at 25°C was predicted and compared. When aging under compression in oil, the prediction lifetime was lower than in air and under compression in air, and in oil. It was clear that when predicting the service lifetime of NBR in oil sealing application, compression and media liquid should be involved simultaneously. Under compression in oil, compression set as the evaluation index, the prediction lifetime of NBR was shorter than that of elongation at break as the evaluation index. For the life prediction of NBR, we should take into account of the performance trends of NBR under actual operating conditions to select the appropriate evaluation index.

Lifetime Prediction and Aging Behaviors of Nitrile Rubber Under Operating Environment of Transformer

Yi-Hua Qian,Hong-zhao Xiao,Ming-hao Nie,Yao-hong Zhao,Yunbai Luo,Shu-ling Gong 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.2

Based on the actual operating environment of transformer, the aging tests of nitrile butadiene rubber (NBR) were conducted systematically under four conditions: in air, in transform oil, under compression in air and under compression in transform oil to studythe effect of high temperature, transform oil and compression stress simultaneously on the thermal aging behaviors of nitrile butadiene rubber and predict the lifetime. The effects of liquid media and compression stress simultaneously on the thermal aging behaviors of nitrile butadiene rubber were studied by using characterization methods such as IR spectrosc-opy, thermogravimetric measurements, Differential Scanning Calorimetry (DSC) measurements and mechanical property measurements. The changes in physical properties during the aging process were analyzed and compared. Different aging conditions yielded materials with different properties. Aging at 70°C under compression stress in oil, the change in elongation at break was lower than that aging in oil, but larger than that aging under compression in air. The compression set or elongation at break as evaluation indexes, 50% as critical value, the lifetime of NBR at 25°C was predicted and compared. When aging under compression in oil, the prediction lifetime was lower than in air and under compression in air, and in oil. It was clear that when predicting the service lifetime of NBR in oil sealing application, compression and media liquid should be involved simultaneously. Under compression in oil, compression set as the evaluation index, the prediction lifetime of NBR was shorter than that of elongation at break as the evaluation index. For the life prediction of NBR, we should take into account of the performance trends of NBR under actual operating conditions to select the appropriate evaluation index.

Finite Difference Based Iterative Learning Control with Initial State Learning for Fractional Order Linear Systems

Yong-Hong Lan,Bin Wu,Yi-Ping Luo 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.2

This paper presents a PI-type iterative learning control (ILC) law with initial state learning for a class of α (0 < α ≤ 1) fractional order linear systems. First, by using backward difference method, the finite difference approximation of the fractional order derivative is obtained, which leads to globally 2−α order accuracy. Then, a PIILC law is constructed at the nodes and the convergence analysis of the iterative scheme is proved. A new sufficient condition is derived to guarantee that the tracking error is asymptotical convergent. The obtained convergence condition is fractional order dependent and is less conservative than the existing one. Most of the classical ILC conditions for fractional order linear systems fall into the special case of this paper. Finally, the simulation results show the effectiveness of the proposed control method.

Lifetime Prediction and Aging Behaviors of Nitrile Butadiene Rubber under Operating Environment of Transformer

Qian, Yi-hua,Xiao, Hong-zhao,Nie, Ming-hao,Zhao, Yao-hong,Luo, Yun-bai,Gong, Shu-ling The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.2

Based on the actual operating environment of transformer, the aging tests of nitrile butadiene rubber (NBR) were conducted systematically under four conditions: in air, in transform oil, under compression in air and under compression in transform oil to studythe effect of high temperature, transform oil and compression stress simultaneously on the thermal aging behaviors of nitrile butadiene rubber and predict the lifetime. The effects of liquid media and compression stress simultaneously on the thermal aging behaviors of nitrile butadiene rubber were studied by using characterization methods such as IR spectrosc-opy, thermogravimetric measurements, Differential Scanning Calorimetry (DSC) measurements and mechanical property measurements. The changes in physical properties during the aging process were analyzed and compared. Different aging conditions yielded materials with different properties. Aging at $70^{\circ}C$ under compression stress in oil, the change in elongation at break was lower than that aging in oil, but larger than that aging under compression in air. The compression set or elongation at break as evaluation indexes, 50% as critical value, the lifetime of NBR at $25^{\circ}C$ was predicted and compared. When aging under compression in oil, the prediction lifetime was lower than in air and under compression in air, and in oil. It was clear that when predicting the service lifetime of NBR in oil sealing application, compression and media liquid should be involved simultaneously. Under compression in oil, compression set as the evaluation index, the prediction lifetime of NBR was shorter than that of elongation at break as the evaluation index. For the life prediction of NBR, we should take into account of the performance trends of NBR under actual operating conditions to select the appropriate evaluation index.

Study the Thermal Behaviours for Asphalt Concrete Mixed with Basic Oxygen Furnace Slags

( Huan-lin Luo ),( Deng-fong Lin ),( Show-ing Shieh ),( Yi-hong Liu ),( Yu-kai Wang ) 한국폐기물자원순환학회(구 한국폐기물학회) 2019 ISSE 초록집 Vol.2019 No.-

In Taiwan, the basic oxygen furnace (BOF) slags are characterized as porous material and with better heat insulation than that of the natural aggregates. The BOF slags have been applied to the pavement as parts of the natural aggregate replacement. The asphalt concrete (AC) with the BOF slags replacements were well recognized and performed. In this study, parts of natural aggregates were replaced by the BOF slags in the AC helping resolve the gradual shortage of the natural resources and save energy and reduce the produce of carbon. In this study, parts of the natural aggregates were replaced by the coarse and fine BOF slags in the construction of AC. Because the thermal insulation and heat absorption are different between BOF slags and natural aggregates, the infrared thermal conductivity measuring instrument was applied to obtain the surface temperatures presented as thermal infrared images in AC. Then, the infrared temperature distribution images were obtained by using the image transformation techniques. The results show that the thermal conductivity for the AC containing with fine BOF slag was larger than that for the coarse BOF slag. The BOG slag replacement in AC helped improve the thermal insulation in AC. Moreover, the temperature was more uniformly distributed for AC with the fine BOF slag than that for the coarse BOF slag replacement. However, the coarse BOF slag was better in the preserve of energy for AC than that of the fine BOF slag.

Effects of tryptophan and phenylalanine on tryptophol production in Saccharomyces cerevisiae revealed by transcriptomic and metabolomic analyses

Gong Xiaowei,Luo Huajun,Hong Liu,Wu Jun,Wu Heng,Song Chunxia,Zhao Wei,Han Yi,Dao Ya,Zhang Xia,Zhu Donglai,Luo Yiyong 한국미생물학회 2022 The journal of microbiology Vol.60 No.8

Tryptophol (TOL) is a metabolic derivative of tryptophan (Trp) and shows pleiotropic effects in humans, plants and microbes. In this study, the effect of Trp and phenylalanine (Phe) on TOL production in Saccharomyces cerevisiae was determined, and a systematic interpretation of TOL accumulation was offered by transcriptomic and metabolomic analyses. Trp significantly promoted TOL production, but the output plateaued (231.02−266.31 mg/L) at Trp concentrations ≥ 0.6 g/L. In contrast, Phe reduced the stimulatory effect of Trp, which was strongly dependent on the Phe concentration. An integrated genomic, transcriptomic, and metabolomic analysis revealed that the effect of Trp and Phe on TOL production was mainly related to the transamination and decarboxylation of the Ehrlich pathway. Additionally, other genes, including thiamine regulon genes (this), the allantoin catabolic genes dal1, dal2, dal4, and the transcriptional activator gene aro80, may play important roles. These findings were partly supported by the fact that the thi4 gene was involved in TOL production, as shown by heterologous expression analysis. To the best of our knowledge, this novel biological function of thi4 in S. cerevisiae is reported here for the first time. Overall, our findings provide insights into the mechanism of TOL production, which will contribute to TOL production using metabolic engineering strategies.

Serum Insulin-Like Growth Factor Binding Protein 7 as a Potential Biomarker in the Diagnosis and Prognosis of Esophagogastric Junction Adenocarcinoma

Can-Tong Liu,Yi-Wei Xu,Hong Guo,Chao-Qun Hong,Xin-Yi Huang,Yu-Hao Luo,Shi-Han Yang,Ling-Yu Chu,En- Min Li,Yu-Hui Peng 거트앤리버 소화기연관학회협의회 2020 Gut and Liver Vol.14 No.6

Background/Aims: Esophagogastric junction adenocarcinoma (EJA) is a malignant tumor associated with high morbidity and has attracted increasing attention due to a rising incidence and low survival rate. Pathological biopsy is the gold standard for diagnosis, but noninvasive and effective tests are lacking, resulting in diagnoses at advanced stages. This study explored the diagnostic value of insulin-like growth factor binding protein 7 (IGFBP7) in EJA. Methods: A total of 120 EJA patients and 88 normal controls were recruited, and their serum levels of IGFBP7 were measured by enzymelinked immunosorbent assay. Receiver operating characteristic (ROC) curve analysis was used to assess the diagnostic value, and Pearson chi-square analysis was used to evaluate the correlation between IGFBP7 and clinical parameters. Kaplan- Meier survival analysis was carried out to assess the effect of IGFBP7 on overall survival (OS). Results: The levels of IGFBP7 were higher in both early- and late-stage EJA patients than in normal controls (p<0.001). The area under the ROC curve for EJA patients was 0.794 (95% confidence interval [CI], 0.733 to 0.854), with a cutoff value of 2.716 ng/mL, a sensitivity of 63.3% (95% CI, 54.0% to 71.8%) and a specificity of 90.9% (95% CI, 82.4% to 95.7%). For the diagnosis of early-stage EJA, the same cutoff value and specificity were obtained, but the sensitivity of IGFBP7 was 54.3% (95% CI, 36.9% to 70.8%). Patients with low IGFBP7 protein expression had lower OS than those with high expression (p=0.034). The multivariate analysis showed that IGFBP7 is an independent prognostic factor for EJA (p=0.011). Conclusions: Serum IGFBP7 acts as a potential diagnostic and prognostic marker for EJA.

Effect of Low Temperature Ge Seed Layer and Post Thermal Annealing on Quality of Ge1-xSix (0.05 ≤ x ≤ 0.1) Graded Buffer Layers by UHV-CVD

Chi-Lang Nguyen,Nguyen Hong Quan,Binh Tinh Tran,Yung-Hsuan Su,Shih-Hsuan Tang,Guang-Li Luo,Edward Yi Chang 대한금속·재료학회 2014 ELECTRONIC MATERIALS LETTERS Vol.10 No.4

High crystal quality, smooth surface and fully relaxed Ge1-xSix (0.05 ≤ x ≤ 0.1) buffers are grown on 6°-off (100) Si substrate by UHV-CVD. A low-temperature (LT) Ge seed layer is used to improve the quality of the Ge1-xSix buffers. In this study, the LT-Ge seed layer is deposited directly onto the Si substrate at a low temperature of 315°C. After that, stress-free Si0.1Ge0.9 and Si0.05Ge0.95 layers are grown, respectively. An in-situ annealing process is also performed for the Si0.1Ge0.9/LT-Ge layers to increase the degree of relaxation. The total thickness of the epitaxial layer is 270 nm, with the average surface roughness at 0.6 nm.

Water-soluble coenzyme Q₁₀ provides better protection than lipid-soluble coenzyme Q₁₀ in a rat model of chronic tacrolimus nephropathy

( Sheng Cui ),( Kang Luo ),( Yi Quan ),( Sun Woo Lim ),( Yoo Jin Shin ),( Kyung Eun Lee ),( Hong Lim Kim ),( Eun Jeong Ko ),( Ju Hwan Kim ),( Sang J. Chung ),( Soo Kyung Bae ),( Byung Ha Chung ),( Chu 대한내과학회 2021 The Korean Journal of Internal Medicine Vol.36 No.4

Background/Aims: Coenzyme Q₁₀ (CoQ₁₀), is a promising antioxidant; however, low bioavailability owing to lipid-solubility is a limiting factor. We developed water-soluble CoQ₁₀ (CoQ₁₀-W) and compared its effects with conventional lipid-soluble CoQ₁₀ (CoQ₁₀-L) in an experimental model of chronic tacrolimus (Tac) nephropathy. Methods: CoQ₁₀-W was developed from a glycyrrhizic-carnitine mixed layer CoQ₁₀ micelle based on acyltransferases. Chronic nephropathy was induced in rats with 28-day Tac treatment; they were concomitantly treated with CoQ₁₀-L or CoQ₁₀-W. CoQ₁₀ level in plasma and kidney were measured using liquid chromatography-mass spectrometry. CoQ₁₀-W and CoQ₁₀-L effects on Tac-induced nephropathy were assessed in terms of renal function, histopathology, oxidative stress, and apoptotic cell death. Their effects on cell viability and reactive oxygen species (ROS) production were assessed in cultured proximal tubular cells, human kidney 2 (HK-2) cells. Results: The plasma CoQ₁₀ level was significantly higher in the CoQ₁₀-W group than in the CoQ₁₀-L group. Tac treatment caused renal dysfunction, typical pathologic lesions, and oxidative stress markers. Serum creatinine was restored in the Tac + CoQ₁₀-L or CoQ₁₀-W groups compared with that in the Tac group. CoQ₁₀-W administration reduced oxidative stress and apoptosis markers. Mitochondrial ultrastructure assessment revealed that the addition of CoQ₁₀-L or CoQ₁₀-W with Tac increased mitochondrial size and number than Tac treatment alone. In vitro investigations revealed that both CoQ₁₀-L and CoQ₁₀-W improved cell viability and reduced ROS production in the Tac-induced HK-2 cell injury. Conclusions: CoQ₁₀-W has a better therapeutic effect in Tac-induced renal injury than conventional CoQ₁₀-L, possibly associated with improved CoQ₁₀ bioavailability.

Identifying Differentially Expressed Genes and Small Molecule Drugs for Prostate Cancer by a Bioinformatics Strategy

Li, Jian,Xu, Ya-Hong,Lu, Yi,Ma, Xiao-Ping,Chen, Ping,Luo, Shun-Wen,Jia, Zhi-Gang,Liu, Yang,Guo, Yu Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.9

Purpose: Prostate cancer caused by the abnormal disorderly growth of prostatic acinar cells is the most prevalent cancer of men in western countries. We aimed to screen out differentially expressed genes (DEGs) and explore small molecule drugs for prostate cancer. Materials and Methods: The GSE3824 gene expression profile of prostate cancer was downloaded from Gene Expression Omnibus database which including 21 normal samples and 18 prostate cancer cells. The DEGs were identified by Limma package in R language and gene ontology and pathway enrichment analyses were performed. In addition, potential regulatory microRNAs and the target sites of the transcription factors were screened out based on the molecular signature database. In addition, the DEGs were mapped to the connectivity map database to identify potential small molecule drugs. Results: A total of 6,588 genes were filtered as DEGs between normal and prostate cancer samples. Examples such as ITGB6, ITGB3, ITGAV and ITGA2 may induce prostate cancer through actions on the focal adhesion pathway. Furthermore, the transcription factor, SP1, and its target genes ARHGAP26 and USF1 were identified. The most significant microRNA, MIR-506, was screened and found to regulate genes including ITGB1 and ITGB3. Additionally, small molecules MS-275, 8-azaguanine and pyrvinium were discovered to have the potential to repair the disordered metabolic pathways, abd furthermore to remedy prostate cancer. Conclusions: The results of our analysis bear on the mechanism of prostate cancer and allow screening for small molecular drugs for this cancer. The findings have the potential for future use in the clinic for treatment of prostate cancer.