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.

Toughening polystyrene by core–shell grafting copolymer polybutadiene-graft-polystyrene with potassium persulfate as initiator

Gui Di Cai,Guang Hui Gao,Hong Yu Yang,Li Dan Zhu,Hua Liu,Guang Feng Wu,Ming Yao Zhang,Chao Zhou,Hui Xuan Zhang 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.3

Core–shell polybutadiene-graft-polystyrene rubber particles with different ratios of polybutadiene core to polystyrene shell were synthesized by an emulsion polymerization using K2S2O8 as an initiator. Then the core–shell rubber particles were blended with PS to prepare PS/PB-g-PS. The rubber particles with a size of 0.3–0.5 mm could toughen polystyrene significantly. The mechanical properties, morphologies and deformation mechanisms of samples were extensively investigated. The experimental results showed that the dispersion of rubber particles in a ‘‘cluster’’ state leads to better impact resistances. Crazing occurred from rubber particles and extended in a bridge-like manner to neighboring rubber particles parallel to the equatorial direction.

Effect of Aging Precipitate on Ductility Anisotropy and Low Cycle Fatigue Behavior of AA2195 Al-Li Alloy

Gui Wang,Ben Lin,Ding‑ding Lu,San‑xi Deng,Guang‑jun Zeng,Xu‑feng Cai,Jin‑feng Li,Dan‑yang Liu 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.8

The mechanical properties and low-cycle fatigue behavior of the hot-rolled AA2195 Al-Li alloy taken along the longitudinaldirection and transverse direction were investigated. The anisotropy ductility of the alloy with the short-term naturalaging (T4-SN), long-term natural aging (T4-LN), and T6 artificial aging alloy is mainly related to the grain structure andgrain boundaries, whereas the weakened anisotropy of ductility is attributed to the appearance of PFZs. The T4-SN andT4-LN specimens present the cyclic hardening phenomenon due to the interaction of dislocations with dislocations or theGuinier–Preston zone. The cyclic softening phenomenon in T6 specimens is attributed to that the dislocations cut throughthe T1precipitates, and some dislocations bypass the non-shearable precipitates, which activates more potential slip systemsto shear the T1precipitates.

A study on submerged rotating MBR for wastewater treatment and membrane cleaning

Dan-Ying Zuo,Hong-Jun Li,Hong-Tao Liu,Gui-Ping Wu 한국화학공학회 2010 Korean Journal of Chemical Engineering Vol.27 No.3

A submerged rotating membrane bioreactor (SRMBR), with a rotatable, rounded, flat-sheet Poly(vinyldiene fluoride) (PVDF) membrane module fixed on hollow axes and moved by an electromotor, was used for wastewater reclamation. It was found that the effluent COD became stable and lower than 20 mg/L after one day running. The equilibrium permeate flux increased from 42.5 to 47.5 L/m2·h with the rotation speed increasing from 15 r/min to 25 r/min. Prolonging relaxation time could alleviate membrane fouling and enhance the flux. Finally, membrane cleaning was studied. The results showed that flushing the membrane surface with water, water/NaOH and water/NaOH/HCl recovered permeate flux to 48.4%, 83.5% and 90.2% of that of the initial operation, respectively.

Deep removal of sulfur from real diesel by catalytic oxidation with halogen-free ionic liquid

Dan Liu,Jianzhou Gui,Yong-Ki Park,Shuang Yang,Yuhuan Gao,Xilai Peng,Zhaolin Sun 한국화학공학회 2012 Korean Journal of Chemical Engineering Vol.29 No.1

A halogen-free task-specific ionic liquid (TSIL) of 1-(2-carboxylic acid) ethyl-3-methylimidazolium bisulfate ([(CH2)2COOHmim] [HSO4]) is applied for deep oxidative desulfurization of real diesel as a catalyst and reaction media. The sulfur level of real diesel can be reduced from 200 to 20.5 μg/g at room temperature with small amount of ionic liquid using H2O2 as an oxidant. The used ionic liquid can be easily recycled and no obvious decrease in catalytic activity can be found after recycling five times.

A Fast Rough Mode Decision Algorithm for HEVC

Wei-Xin Yao,Dan Yang,Gui-Fu Lu,Jun Wang 한국정보처리학회 2019 Journal of information processing systems Vol.15 No.3

HEVC is the high efficiency video coding standard, which provides better coding efficiency contrasted with theother video coding standard. But at the same time the computational complexity increases drastically. Thirtyfivekinds of intra-prediction modes are defined in HEVC, while 9 kinds of intra prediction modes are definedin H.264/AVC. This paper proposes a fast rough mode decision (RMD) algorithm which adopts the smoothnessof the up-reference pixels and the left-reference pixels to decrease the computational complexity. The three stepsearch method is implemented in RMD process. The experimental results compared with HM13.0 indicate thatthe proposed algorithm can save 39.7% of the encoding time, while Bjontegaard delta bitrate (BDBR) isincreased slightly by 1.35% and Bjontegaard delta peak signal-to-noise ratio (BDPSNR) loss is negligible.

A Fast Rough Mode Decision Algorithm for HEVC

Yao, Wei-Xin,Yang, Dan,Lu, Gui-Fu,Wang, Jun Korea Information Processing Society 2019 Journal of information processing systems Vol.15 No.3

HEVC is the high efficiency video coding standard, which provides better coding efficiency contrasted with the other video coding standard. But at the same time the computational complexity increases drastically. Thirty-five kinds of intra-prediction modes are defined in HEVC, while 9 kinds of intra prediction modes are defined in H.264/AVC. This paper proposes a fast rough mode decision (RMD) algorithm which adopts the smoothness of the up-reference pixels and the left-reference pixels to decrease the computational complexity. The three step search method is implemented in RMD process. The experimental results compared with HM13.0 indicate that the proposed algorithm can save 39.7% of the encoding time, while Bjontegaard delta bitrate (BDBR) is increased slightly by 1.35% and Bjontegaard delta peak signal-to-noise ratio (BDPSNR) loss is negligible.

Immunization of BALB/c mice with Brucella abortus 2308DwbkA confers protection against wild-type infection

Zhi-qiang Li,Dan Gui,Zhi-hua Sun,Jun-bo Zhang,Wen-zhi Zhang,Hui Zhang,Fei Guo,Chuangfu Chen 대한수의학회 2015 Journal of Veterinary Science Vol.16 No.4

Brucellosis is a zoonotic disease that causes animal and human diseases. Vaccination is a major measure for prevention of brucellosis, but it is currently not possible to distinguish vaccinated animals from those that have been naturally infected. Therefore, in this study, we constructed the Brucella (B.) abortus 2380 wbkA mutant (2308DwbkA) and evaluated its virulence. The survival of 2308DwbkA was attenuated in murine macrophage (RAW 264.7) and BALB/c mice, and it induced high protective immunity in mice. The wbkA mutant elicited an anti-Brucella-specific immunoglobulin G response and induced the secretion of gamma interferon. Antibodies to 2308DwbkA could be detected in sera from mice, implying the potential for use of this protein as a diagnostic antigen. The WbkA antigen would allow serological differentiation between infected and vaccinated animals. These results suggest that 2308DwbkA is a potential attenuated vaccine against 16M. This vaccine will be further evaluated in sheep.

Toward the Insights into Fast CO₂ Absorption over Novel Nanostructured MgO-Based Sorbent

Yang, Lixia,Liu, Dan,Wang, Pingping,Seo, Hwimin,Gui, Jianzhou,Park, Yong-Ki American Chemical Society 2018 INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH - Vol.57 No.31

<P>A uniform nanoplate-like MgO-based sorbents were prepared with eitelite and hydromagnesite intergrowing each other, and their CO<SUB>2</SUB> capture capacity was evaluated for fast CO<SUB>2</SUB> absorption in the thermal swing absorption process, with model wet industrial flue gas at a CO<SUB>2</SUB> concentration of 14.5 vol %, at ambient pressure. Fast absorption and desorption rate, acceptable dynamic absorption capacity, and good cyclic stability (9 wt % after recycling 100 times) have been obtained. Some theoretical work has been carried out and found eitelite was the only origin of the active MgO species for fast CO<SUB>2</SUB> uptake in TSA process. Nitrate was also demonstrated to have some promotive effect in CO<SUB>2</SUB> fast absorption on the active MgO species. The effectiveness of eitelite was close related to its special crystal structure, i.e., after calcination, the special layer assembling with the proximity of Na<SUP>+</SUP> and O<SUP>2-</SUP> at a molecular level probably contributed to the fast absorption. Meanwhile, the void space caused by decarbonization of hydromagnesite may also facilitate the absorption and diffusion of CO<SUB>2</SUB>. Therefore, this sorbent has been demonstrated to be a potential absorbent for postcombustion CO<SUB>2</SUB> capture from fossil-fuel-fired power plant.</P> [FIG OMISSION]</BR>

The BRAF^T1799A Mutation is not Associated with Occult Contralateral Carcinoma in Patients with Unilateral Papillary Thyroid Microcarcinoma

Wan, Han-Feng,Zhang, Bin,Yan, Dan-Gui,Xu, Zhen-Gang Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.7

Background: The phenomenon of occult carcinoma maybe observed in patients with clinically unilateral papillary thyroid microcarcinoma (PTMC). Although many studies have reported that the $BRAF^{T1799A}$ mutation is associated with aggressive PTMC, the relationship between $BRAF^{T1799A}$ mutation and occult carcinoma is unclear. The aim of this study was to investigate the risk factors, including $BRAF^{T1799A}$ mutation, for occult contralateral carcinoma in clinically unilateral PTMC accompanied by benign nodules in the contralateral lobe. Materials and Methods: From January 2011 to December 2013, we prospectively enrolled 89 consecutive PTMC patients with clinically unilateral carcinoma accompanied by benign nodules in the contralateral lobe who received a total thyroidectomy and cervical lymph node dissection. $BRAF^{T1799A}$ mutation was tested by pyrosequencing on postoperative paraffin specimens. The frequency and predictive factors for occult contralateral carcinoma were analyzed with respect to the following variables: age, gender, family history, tumor size, presence of Hashimoto thyroiditis, extrathyroidal extension, central lymph node metastasis, multifocality of primary tumor, or $BRAF^{T1799A}$ mutation. Results: A total of 36 patients (40.4%) had occult PTMC in the contralateral lobe. The median diameter of the occult tumors was $0.33{\pm}0.21cm$. The $BRAF^{T1799A}$ mutation was found in 38 cases (42.7%). According to the univariate analysis, there were no significant differences between the presence of occult contralateral carcinoma and age, gender, family history, tumor size, presence of Hashimoto thyroiditis, extrathyroidal extension, central lymph node metastasis, multifocality of primary tumor, or $BRAF^{T1799A}$ mutation. Conclusions: Using current methods, it is difficult to preoperatively identify patients with PTMC, and further research is needed to determine predictive factors for the presence of occult contralateral carcinoma in patients with unilateral PTMC.