Effect of Temperature on Resistivity of CFRP Materials with Added Carbon Powder or Nano-silica

Dan Liu,Jie Yin,Rong-gui Liu,Shu Ping,Hui-guang Yin,Gui-hua Xie 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.4

This paper presents an experimental investigation on the effect of temperature on resistivity of Carbon Fiber Reinforced Polymer (CFRP) materials. A series of tests were conducted on three types of CFRP materials, namely pure CFRP material, CFRP with carbon powder (4% in weight) and CFRP with nano-silica (4% in weight). Test results showed that adding carbon powder into the epoxy resin decreases the initial electric resistance R0 and initial volume resistivity ρ0 while adding nano-silica increases R0 and ρ0 compared to pure CFRP material. Preheating cycle test results showed that the volume resistivity of all three types of specimens linearly increases with increasing temperature. CFRP with added nano-silica exhibits higher temperature sensitivity than CFRP with added carbon powder compared to the lowest temperature sensitivity for pure CFRP material. In addition, temperature cycle test results showed that CFRP specimens have approximately stable values of volume resistivity. Both CFRP specimens with added carbon powder or nano-silica exhibit a recognizable trend of first decrease and then increase in volume resistivity with increasing temperature both during heating and cooling cycles. CFRP with added carbon powder mainly shows Negative Temperature Coefficient (NTC) effect in the temperature range of −40 to 40oC and Positive Temperature Coefficient (PTC) effect from 40 to 80oC. CFRP with added nano-silica mainly exhibits PTC effect in the temperature domain of −15 to 80oC and NTC effect from −40 to −15oC. A mathematical-physical model with respect to the thermal effect was presented based on the Eshelby-Mori-Tanaka (EMT) approach and mesomechanics method. The results obtained with the model agree well with the test results considering the temperature domain of PTC effect, which indicates that the proposed model is effective in characterizing the variation of fractional change in resistance (ΔR/R0) at varying temperature.

ZNF488 Enhances the Invasion and Tumorigenesis in Nasopharyngeal Carcinoma Via the Wnt Signaling Pathway Involving Epithelial Mesenchymal Transition

Dan Zong,Li Yin,Qian Zhong,Wen-jie Guo,Jian-hua Xu,Ning Jiang,Zhi-rui Lin,Man-zhi Li,Ping Han,Lin Xu,Xia He,Mu-sheng Zeng 대한암학회 2016 Cancer Research and Treatment Vol.48 No.1

Purpose The purpose of this study was to investigate the function of Zinc finger protein 488 (ZNF488) in nasopharyngeal carcinoma (NPC). Materials and Methods The endogenous expression of ZNF488 in NPC tissues, normal nasopharyngeal epithelium tissues and NPC cell lines were detected by quantitative reverse transcription polymerase chain reaction. ZNF488 over-expressing and knock-down NPC cell line models were estab- lished through retroviral vector pMSCV mediated over-expression and small interfering RNA (siRNA) mediated knock-down. The invasion and migration capacities were evaluated by wound healing and transwell invasion assays in ZNF488 over-expressing and control cell lines. Soft-agar colony formation and a xenograft experiment were performed to study tumorigenic ability in vitro and in vivo. Immunofluorescence and western blotting analysis were used to examine protein changes followed by ZNF488 over-expression. Microarray analysis was performed to explore gene expression profilings, while luciferase reporter assay to evaluate the transcriptive activity of Tcf/Lef. Results ZNF488 was over-expressed in NPC tissues compared with normal tissues, especially higher in 5-8F and S18, which are well-established high metastatic NPC clones. Functional studies indicate that over-expression of ZNF488 provokes invasion, whereas knock-down of ZNF488 alleviates invasive capability. Moreover, over-expression of ZNF488 promotes NPC tumor growth both in vitro and in vivo. Our data further show that over-expression of ZNF488 induces epithelial mesenchymal transition (EMT) by activating the WNT/β -catenin signaling pathway. Conclusion Our data strongly suggest that ZNF488 acts as an oncogene, promoting invasion and tumorigenesis by activating the Wnt/β -catenin pathway to induce EMT in NPC.

An Optical Zoom System Based on Tunable Lens with Polymer Membrane and Multilayered Structure

Dan Liang,Dong Tai Liang,Xuan Yin Wang 한국고분자학회 2018 폴리머 Vol.42 No.6

We have developed an optical zoom system based on tunable lens with polymer membrane and multilayered structure. The presented system employed two tunable lenses and two doublet lenses as the main refractive units. Each tunable lens had a delicately designed, solid-liquid mixed structure with multiple internal slim holes, which helped to improve the lens optical properties and stability against gravity. The optical structure and regulation principle of the zoom system is presented, as well as the detailed fabrication process of the tunable lens. Under different displacement loads, the lens deformation properties, and the adjustment ability and imaging characteristics of the zoom system were measured and analyzed. Besides, the spot diagram, field curvature and distortion of the system were simulated using the Zemax software. The magnification of the designed system could be regulated from 0.2X to 4.3X flexibly depending on the focal variation of each tunable lens.

Research on Constitutive Models and Hot Workability of As-Homogenized Al- Zn-Mg-Cu Alloy During Isothermal Compression

Dan Xiao,Xiaoyan Peng,Xiaopeng Liang,Ying Deng,Guofu Xu,Zhimin Yin 대한금속·재료학회 2017 METALS AND MATERIALS International Vol.23 No.3

Hot compression tests of as-homogenized Al-Zn-Mg-Cu alloy were performed at the deformation temperaturerange of 350-450 °C and the strain rate range of 0.001-1 s-1. The Arrhenius-type constitutive equation and theAvrami-type model were established to predict the flow behaviors of the alloy respectively. The processing map atthe true strain of 0.92 was developed to evaluate the workability of the alloy and the related microstructures wereinvestigated. The results show that the Avrami-type model has a higher accuracy to predict flow stress than theArrhenius-type constitutive equation. The stable deformation occurs under high temperature or low strain ratemainly owing to the dynamic recrystallization. Flow instability is prone to occur under the condition of low temperatureand high strain rate due to the initiation and the propagation of micro-cracks. According to the processingmap and corresponding microstructure characteristics, the optimum processing parameters are in the temperaturerange of 380-405 °C and the strain rate range of 0.006-0.035 s-1.

Kinetics of Sn(Oct)2-Catalyzed Ring Opening Polymerization of ε-Caprolactone

Dan Wu,Yin Lv,Rui Guo,Jiahui Li,Aerman Habadati,Bowen Lu,Heyun Wang,Zhong Wei 한국고분자학회 2017 Macromolecular Research Vol.25 No.11

To evaluate the effects of different alcohols (primary, secondary, and two different tertiary alcohols) as initiators on the structure of polycaprolactone (PCL) in ring-opening polymerization (ROP), four experiments were conducted in toluene with tin(II) 2-ethylhexanoate (Sn(Oct)2) as the catalyst. The kinetics of ε-caprolactone (ε-CL) ROP at different temperatures and monomer concentrations were studied with n-butanol as the initiator and Sn(Oct)2 as the catalyst. The kinetic plot of ln(M0/Mt) vs. time (t) seems a linear, which indicates that the propagation rate is in the first order with respect to monomer concentration. When the reaction temperature increased, the reaction rate and the final relative maximum monomer conversions also increased. The molecular weight of PCL initially increased and then decreased as monomer conversion increased. This behavior can be attributed to the high viscosity of the system, which affected monomer diffusion and polymer chain propagation. In addition, prolonging reaction time caused inter-/intramolecular transesterification. However, when monomer concentration decreased, the reaction rate decreased. The actual activation energy of Sn(Oct)2-catalyzed ROP of ε-CL in toluene was -75 kJ/mol.

Molecular characterization and expression of suppressor of cytokine signaling (SOCS) 1, 2 and 3 under acute hypoxia and reoxygenation in pufferfish, Takifugu fasciatus

Dan Wang,Xin Wen,Xinyu Zhang,Yadong Hu,Xinru Li,Wenxu Zhu,Tao Wang,Shaowu Yin 한국유전학회 2018 Genes & Genomics Vol.40 No.11

Hypoxia seriously affects the innate immune system of fish. However, the roles of suppressor of cytokine signaling (SOCS), pivotal anti-inflammatory genes, in response to hypoxia/reoxygenation remain largely unexplored. The primary objective of this study was to elucidate the function of SOCS genes under acute hypoxia and reoxygenation in pufferfish (Takifugu fasciatus). In the present study, SOCS1, 2 and 3 were identified in T. fasciatus referred to as TfSOCS1, 2 and 3. Then, qRTPCR and western blot analysis were employed to assess their expressions at both the mRNA and protein levels. Tissue distribution demonstrated that the three SOCS genes were predominantly distributed in gill, brain and liver. Under hypoxia challenge (1.63 ± 0.2 mg/L DO for 2, 4, 6 and 8 h), the expressions of TfSOCS1 and 3 in brain and liver at the mRNA and protein levels were significantly decreased, while their expressions showed an opposite trend in gill. Different from the expressions of TfSOCS1 and 3, the expression of TfSOCS2 was inhibited in gill, along with its increased expression in brain and liver. After normoxic recovery (7.0 ± 0.3 mg/L of DO for 4 and 12 h), most of TfSOCS genes were significantly altered at R4 (reoxygenation for 4 h) and returned to the normal level at R12 (reoxygenation for 12 h). SOCS genes played vital roles in response to hypoxia/reoxygenation challenge. Our findings greatly strengthened the relation between innate immune and hypoxia stress in T. fasciatus.

Fabrication and Analyses of Bionic Polymer Lens System

Xuan Yin Wang,Dan Liang,Feng Tang,Jia Wei Du 한국고분자학회 2016 폴리머 Vol.40 No.2

In this paper, we design and fabricate a bionic solid tunable lens which is mainly made of polymer materials. The lens focal length can be changed flexibly by pressing the lens surface to alter the curvature radius. A detailed description of the lens structure, materials and fabrication process is presented. The lens mechanical properties and deformation process are simulated and analyzed using Ansys software. A precise experimental device based on a stepping motor is fabricated to measure and analyze the relationship between the displacement load and focal length. The lens focal length can be reversibly changed from 31.8 to 14.1 mm under 1 mm variation of displacement load. This paper offers a feasible way for the design, fabrication, and actuation of the solid tunable lens, which can be used in various machine vision apparatus.

Preliminary Evaluation of the in vitro Efficacy of 1, 2-di (Quinazolin-4-yl) Diselane against SiHa Cervical Cancer Cells

Huang, Yin-Jiu,Zhang, Yu-Yuan,Liu, Gang,Tang, Jie,Hu, Jian-Guo,Feng, Zhen-Zhong,Liu, Fang,Wang, Qi-Yi,Li, Dan Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.15

Cervical cancer is one the most common malignancies among females. In recent years, its incidence rate has shown a rising trend in some countries so that development of anticancer drugs for cervical cancer is an urgent priority. In our recent anticancer drug discovery screen, 1, 2-di (quinazolin-4-yl)diselane (LG003) was found to possess wide spectrum anticancer efficacy. In the present work, the in vitro anticancer activity of LG003 was evaluated in the SiHa cervical cancer cell line. Compared with commercial anticancer drugs 10-hydroxycamptothecin, epirubicin hydrochloride, taxol and oxaliplatin, LG003 showed better anticancer activity. Furthermore, inhibition effects were time- and dose-dependent. Morphological observation exhibited LG003 treatment results in apoptosis like shrinking and blebbing, and cell membrane damage. Lactate dehydrogenase release assay revealed that LG003 exerts such effects in SiHa cells through a physiology pathway rather than cytotoxicity, which suggests that title compound LG003 can be a potential candidate agent for cervical cancer.

모 브랜드 자산이 확장 브랜드 태도 및 이용의도에 미치는 영향 - 외식 프랜차이즈 브랜드를 중심으로 -

채단비 ( Dan Bi Chae ),옌광위 ( Yin Guang Yu ),박진용 ( Jing Yong Park ) 한국유통물류정책학회 2014 유통물류연구 Vol.1 No.2

최근 외식산업의 잠재성이 커지고 경쟁이 점점 치열해지고 있다. 이에 외식산업에서는 소비자의 보다 많은 욕구를 충족시키기 위해 기존의 잘 알려진 브랜드 명으로 브랜드를 확장하는 전략을 적극적으로 도입하고 있다. 특히 국내 외식산업 가운데, 많은 비중은 프랜차이즈 브랜드가 차지하고 있다. 기업 차원에서 브랜드 확장 전략은 프랜차이즈 산업에서 보다 더 활용하기가 수월한 이점이 있다. 이러한 배경 하에 프랜차이즈업체의 기존 브랜드를 이용하여 브랜드를 확장하는 사례가 점점 증가하고 있다. 성공적인 브랜드 확장을 위해 마케터는 브랜드 확장 태도에 미치는 영향 요인을 파악하여 강화할 필요가 있다. 이에 따라 본 연구는 외식 프랜차이즈 모 브랜드와 모 브랜드에서 확장된 브랜드를 모두 이용경험이 있는 고객을 대상으로 브랜드자산을 측정하였다. 추가적으로 소비자가 지각하는 모 브랜드 자산이 확장 브랜드 태도에 미치는 영향에 대해 알아보았으며, 확장 브랜드 태도에 미치는 요인에 관하여 브랜드 자산 중 경영전략의 활용에서 어떠한 측면을 더 강조해야 하는지에 대해 살펴보았다. 이를 위해 본 연구는 모 브랜드 자산이 확장 브랜드 태도 및 이용의도 간 관계를 연구모형으로 도식화하였다. 연구결과, 모 브랜드와 확장 브랜드 이용경험이 있는 고객이 지각하는 브랜드 자산 중 브랜드 이미지, 브랜드 충성도는 확장 브랜드 태도에 유의한 영향을 미치는 것으로 확인되었다. 또한 확장 브랜드와 모 브랜드 간의 유사성과 컨셉 일치성이 모 브랜드 자산과 확장 브랜드 태도간의 관계에 조절효과가 있는 것으로 나타났다. 마지막으로 확장 브랜드 태도는 확장 브랜드에 대한 이용의도에 유의한 영향을 미치는 것으로 확인하였다. 본 연구 결과에 따라 성공한 브랜드 확장을 위해 모 브랜드자산을 통해 확장 브랜드 태도에 긍정적으로 형성하기 위해서는 모 브랜드 이미지 및 브랜드에 대한 충성도를 강화해야 한다. 또한 마케터는 확장 브랜드에 대한 브랜드 태도를 높이기 위해 모 브랜드 이미지 및 충성도의 구축을 위한 노력해야 할 것이다. Recently, the potential of dine-out industry is becoming greater and the competition is getting intense. In order to meet the increasing requirements of consumers, the dine-out industry is applying the method of brand extending as its solution. In addition, cases in which franchise brands extend their brand name is also increasing. Thus marketers in the franchise industry must concentrate on the brand extension strategy. In this study, brand equity is measured through consumers who have used both the parent company and its extended brand in the dine-out franchise industry. This study was designed with the hypothesis that the parent brand equity has significant influence on the attitude of consumers towards the extended brands. The result of the survey showed that the customers, who have used both the parent brand and the extended brand, are considering the parent brand image in the evaluation of the extended brand. In addition, the similarity and concept consistency between the parent and the extended brand may have a moderating effect between the parent brand equity and the attitudes of the extended brand. Finally, it has been confirmed that the attitude of the consumers towards the parent brand have a positive impact on the intention of choosing the extended brand. This study implies that marketers in the franchise industry should try hard to build the parent brand image and loyalty to be successful with the extended brand as well.

체세포 핵이식에 의한 연변황우 복제수정란 생산 및 이식

Jin-dan Kang,Qing-shan Gao,Chang-guo Yan,Xi-Jun Yin 한국동물번식학회 2011 Reproductive & Developmental Biology(Supplement) Vol.35 No.2s