Hydrophobic modification of silica/exfoliated graphite nanoplatelets aerogel and its application as supporting material for form-stable phase change materials

Ni Tan,Yang Feng,Ping Hu,QiLin Ding,Chuan-Huang Lin,Yu-Hao Ning,Hao-Nan Zhou,Linping Yu,Zhong Cao,Ju-Lan Zeng 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.99 No.-

Hydrophobic modified silica/exfoliated graphite nanoplatelets aerogel (M-SiO2/xGnP) were successfullyprepared via surface modification of silica/xGnP alcogel and followed by ambient pressure drying. Afterwards, form-stable PCMs in which capric–palmitic acids eutectic (CA–PA) was confined in theprepared aerogels were obtained by vacuum infiltration. Characterization of the prepared form-stablePCMs revealed that both the hydrophobic modification and the doping of xGnP could effectively improvethe loading of CA–PA in the aerogel. The unmodified silica aerogel could not adsorb CA–PA, while theloading of CA–PA in the surface modified pure silica aerogel supported form-stable PCM and theunmodified silica/xGnP aerogel supported form-stable PCM were 24.2 wt% and 44.4 wt%, respectively. Besides, the hydrophobic modification and the doping of xGnP showed significant synergistic effect. Theloading of CA–PA in the M-SiO2/xGnP supported form-stable PCM (FPCM/xGnP-20-48) could attain78.9 wt% when the M-SiO2/xGnP was obtained by modifying the alcogel with 20 vol% trimethylchlorosilane for 48 h. The FPCM/xGnP-20-48 not only had high latent heat and good thermal reliability,but also exhibited significantly improved thermal conductivity and alleviated supercooling due to theeffective thermal conductive network formed by xGnP and the promoted heterogeneous nucleation ofCA–PA at interfaces with aerogel.

공공서비스동기가 자원봉사활동에 미치는 영향 : 중국 대학생을 중심으로

담효니(Xiao-ni Tan),류근필(Geunpil Ryu),문성진(SEONGGIN MOON) 한국지방행정학회 2021 한국지방행정학보 (KLAR) Vol.18 No.2

이 연구는 중국 대학생의 공공서비스동기와 자원봉사참여의 유의미한 관련성 여부를 탐색하고자 한다. 이를 위해 기존 연구들을 바탕으로 하여 개념들 간의 이론적 관계가 가설화되었으며, 중국 충칭직할시에 소재하고 있는 주요 대학교 (충칭대학교, 충칭사범대학교, 충칭의과대학교)의 재학생들을 대상으로 설문조사를 실시하였다. 설문조사결과를 토대로 공공서비스동기와 자원봉사참여간의 통계적 상관관계를 회귀분석모델을 통해 분석하고 가설을 검증하였다. 통제요인으로는 인구사회학적 요인, 사회자본 요인, 종교 활동, 가족 내의 사회화과정을 포함하였다. 분석결과, 종교 활동, 공공서비스동기 요인(헌신)이 자원봉사활동에 대한 정(+)적 영향을 미치는 것으로 나타났다. 이러한 결과는 이론적으로 공공서비스이론 연구의 발전에 일조할 수 있을 뿐만 아니라 실무적으로는 자원봉사활동이 지속적으로 발전하고 이를 실시하는 데 있어서도 도움이 될 것으로 기대된다. This study pays attention to a recent growing trend of participation in volunteer activities among Chinese college students. It seeks to understand what factors can affect volunteer participation. Particularly, it focuses on public service motivation (PSM) and investigates empirically how PSM can influence volunteering. To examine, we conducted a survey questionnaires administered to students registered in three main universities (Chongqing University, Chongqing Normal University, and Chongqing Medical University) in Chongqing, China. Based on the survey data, this study constructed an OLS regression model to estimate the effect of PSM on volunteer participation. After controlling for factors such as demographic factors, social capital, religious activities and socialization processes in the family, the empirical result showed that PSM is partially significant in terms of affecting volunteer participation. A PSM dimension (sacrifice) is statically significant and the other dimensions (sympathy and civic duty) are not significant. In addition, religious activities have a statistically significant effect on volunteering.

Role of a Novel Pyridostigmine Bromide-Phospholipid Nanocomplex in Improving Oral Bioavailability

Qun-you Tan,Jing-qing Zhang,Ni-ni Hu,Guo-dong Liu,Hua-feng Yin,Li Zhang,Hong Wang,Lu-yang Lu 대한약학회 2012 Archives of Pharmacal Research Vol.35 No.3

A novel pyridostigmine bromide (PB)-phospholipid nanocomplex (PBPLC) was prepared to increase the bioavailability of PB. A central composite design approach was employed for process optimization. The physicochemical properties of PBPLC were investigated by means of differential scanning calorimetry, ultraviolet spectroscopy, Fourier transformed infrared spectroscopy and the n-octano/water partition coefficient. The intestinal permeability of PBPLC was observed via a single pass intestinal perfusion in rats. After oral administration of PBPLC, the concentrations of PB at predetermined time points were determined by HPLC, and the pharmacokinetic parameters were computed by DAS 2.1.1 software. Multiple linear regression analysis for process optimization revealed that the optimal PBPLC was obtained when the values of X1, X2, and X3 were 8, 40oC, and 4 mg/mL, respectively. The average particle size and zeta potential of PBPLC with the optimized formulation were 204.60 nm and −25.12 mV, respectively. Non-covalent interactions between PB and phospholipids were found in the PBPLC. The n-octanol/water partition coefficient of PBPLC was substantially increased. PBPLC had better intestinal permeability in comparison with free PB. Mean plasma drug concentration-time curves of PBPLC and free PB after oral administration were both in accordance with the two-compartment open model. The values of pharmacokinetic parameters of PBPLC and free PB were the peak time (Tmax) 2 h vs 2 h, the maximum concentration (Cmax) 22.79 μg/mL vs 6.00 μg/mL, and the value of the area under the concentration vs time curve (AUC0-∞) 7128.21 μg·min/mL vs 1772.36 μg·min/mL, respectively. In conclusion, compared with free PB, PBPLC remarkably improves the oral bioavailability of PB, which is likely due to its higher lipophilicity and permeability.

Quasi-Periodic Nanoripples in Graphene Grown by Chemical Vapor Deposition and Its Impact on Charge Transport

Ni, Guang-Xin,Zheng, Yi,Bae, Sukang,Kim, Hye Ri,Pachoud, Alexandre,Kim, Young Soo,Tan, Chang-Ling,Im, Danho,Ahn, Jong-Hyun,Hong, Byung Hee,Ö,zyilmaz, Barbaros American Chemical Society 2012 ACS NANO Vol.6 No.2

<P>The technical breakthrough in synthesizing graphene by chemical vapor deposition methods (CVD) has opened up enormous opportunities for large-scale device applications. To improve the electrical properties of CVD graphene grown on copper (Cu-CVD graphene), recent efforts have focused on increasing the grain size of such polycrystalline graphene films to 100 μm and larger. While an increase in grain size and, hence, a decrease of grain boundary density is expected to greatly enhance the device performance, here we show that the charge mobility and sheet resistance of Cu-CVD graphene is already limited within a single grain. We find that the current high-temperature growth and wet transfer methods of CVD graphene result in quasi-periodic nanoripple arrays (NRAs). Electron-flexural phonon scattering in such partially suspended graphene devices introduces anisotropic charge transport and sets limits to both the highest possible charge mobility and lowest possible sheet resistance values. Our findings provide guidance for further improving the CVD graphene growth and transfer process.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2012/ancac3.2012.6.issue-2/nn203775x/production/images/medium/nn-2011-03775x_0005.eps'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn203775x'>ACS Electronic Supporting Info</A></P>

Graphene–Ferroelectric Hybrid Structure for Flexible Transparent Electrodes

Ni, Guang-Xin,Zheng, Yi,Bae, Sukang,Tan, Chin Yaw,Kahya, Orhan,Wu, Jing,Hong, Byung Hee,Yao, Kui,Ö,zyilmaz, Barbaros American Chemical Society 2012 ACS NANO Vol.6 No.5

<P>Graphene has exceptional optical, mechanical, and electrical properties, making it an emerging material for novel optoelectronics, photonics, and flexible transparent electrode applications. However, the relatively high sheet resistance of graphene is a major constraint for many of these applications. Here we propose a new approach to achieve low sheet resistance in large-scale CVD monolayer graphene using nonvolatile ferroelectric polymer gating. In this hybrid structure, large-scale graphene is heavily doped up to 3 × 10<SUP>13</SUP> cm<SUP>–2</SUP> by nonvolatile ferroelectric dipoles, yielding a low sheet resistance of 120 Ω/□ at ambient conditions. The graphene–ferroelectric transparent conductors (GFeTCs) exhibit more than 95% transmittance from the visible to the near-infrared range owing to the highly transparent nature of the ferroelectric polymer. Together with its excellent mechanical flexibility, chemical inertness, and the simple fabrication process of ferroelectric polymers, the proposed GFeTCs represent a new route toward large-scale graphene-based transparent electrodes and optoelectronics.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2012/ancac3.2012.6.issue-5/nn3010137/production/images/medium/nn-2012-010137_0008.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn3010137'>ACS Electronic Supporting Info</A></P>

A Study about Curve Extraction and Lane Departure Determination of Linear Curved Road

Da-Ni Joo,Sang-Chan Moon,Min-Woo Kim,Soon-Geul Lee,Bui Quang Tan 제어로봇시스템학회 2014 제어로봇시스템학회 국제학술대회 논문집 Vol.2014 No.10

Recently, intelligent vehicle are required accurate information about road condition for safety driving. However, vehicle safety systems are irregularly caused an error in judgment by road patterns. In this study, which has extracted curve road segments from line information of GIS with alignment of road. This algorithm are based modified Bezier curve method to detect curve lines from straight lines. Extracted line information are formally analyzed with lane departure warning system (LDWS) that was robust curves. For performance evaluation, the system has installed DGPS with 20cm RMS and WAVE communication with 5.8GHz, and implemented vehicle test in road environment with groups of curves and straight lines. Curvature LDWS improve correctness criterion by applying to predicted trajectory condition to previous algorithm. Test results are shown robust determination and confirmed false alarm did not appear. Furthermore, this algorithm are not only reduced error of functioning properly, but also detected lane departure at all-road environments in real-time.

Experimental and numerical investigation on post-earthquake fire behaviour of the circular concrete-filled steel tube columns

Yu-Hang Wang,Qi Tang,Mei-Ni Su,Ji-Ke Tan,Wei-Yong Wang,Yong-Sen Lan,Xiao-Wei Deng,Yong-Tao Bai,Wei Luo,Xiao-Hua Li,Jiu-Lin Bai 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.38 No.1

Post-earthquake fire is a common disaster which causes serious safety issues to infrastructures. This study aims to investigate the residual loading capacities of circular concrete-filled steel tube (CFST) columns under post-earthquake fire experimentally and numerically. The experimental programme contains two loading steps - pre-damage cyclic loading at room temperature and transient state tests with constant compression loads. Three finite element models are developed and validated against the test results. Upon validation, a total of 48 numerical results were generated in the parametric study to investigate the effects of thickness and strengths of steel tube, axial compression ratio and damage degree on the fire resistance of circular CFST columns. Based on the analysis on experimental and numerical results, the loading mechanism of circular CFST columns is discussed. A design method is proposed for the prediction of fire resistance time under different seismic pre-damage and compression loads. The predictions by the new method is compared with the newly generated experimental and numerical results and is found to be accurate and consistent with the mean value close to the unity and a coefficient of variation around 1%.

A novel and effective approach to enhance the interfacial interactions of meta-aramid fibers

Hui Zhang,Xiaoyun Du,Jiawei Liu,YunHong Bai,Jingyi Nie,Jiaojun Tan,Zhibin He,Meiyun Zhang,Jinbao Li,Yonghao Ni 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.120 No.-

Meta-aramid paper exhibits some unique properties, including high temperature resistance, electricalinsulation. However, due to the inherent chemical inertness of aramid fibers, the interfacial bondingbetween fibers is weak, which negatively affect the properties of aramid paper. Herein, we report a simple,effective and scalable process for substantially improving the interfacial bonding between aramidfibers, thus, mechanical and insulating properties of the meta-aramid composite paper, and it wasachieved by surface coating of aramid paper with meta-aramid stock solution that contains N, N dimethylacetamide(DMAc)-CaCl2 and high molecular weight poly (m-phenylene isophthalamide) polymers. Results show that the tensile strength, modulus, internal bond strength and tearing index of the resultantall-PMIA paper increased by 83 %, 58 %, 173 % and 89 %, respectively, in comparison with those of the control. The breakdown strength of the improved aramid paper is 190 % higher than that of the control paper,attaining 26.46 KV/mm. This work provides a simple, economical, efficient, and scalable method toimprove the overall performance of meta-aramid paper, which has great potential to be implementedat the industrial scale.

Epidemiology and trends in the antibiotic susceptibilities of Gram-negative bacilli isolated from patients with intra-abdominal infections in the Asia-Pacific region, 2010-2013

Chang, Y.T.,Coombs, G.,Ling, T.,Balaji, V.,Rodrigues, C.,Mikamo, H.,Kim, M.J.,Rajasekaram, D.G.,Mendoza, M.,Tan, T.Y.,Kiratisin, P.,Ni, Y.,Barry, W.,Xu, Y.,Chen, Y.H.,Hsueh, P.R. Elsevier Science Publishers ; Elsevier Science Pub 2017 International Journal of Antimicrobial Agents Vol.49 No.6

This study was conducted to investigate the epidemiology and antimicrobial susceptibility patterns of Gram-negative bacilli (GNB) isolated from intra-abdominal infections (IAIs) in the Asia-Pacific region (APR) from 2010-2013. A total of 17 350 isolates were collected from 54 centres in 13 countries in the APR. The three most commonly isolated GNB were Escherichia coli (46.1%), Klebsiella pneumoniae (19.3%) and Pseudomonas aeruginosa (9.8%). Overall, the rates of extended-spectrum β-lactamase (ESBL)-producing E. coli and K. pneumoniae were 38.2% and 24.3%, respectively, and they were highest in China (66.6% and 38.7%, respectively), Thailand (49.8% and 36.5%, respectively) and Vietnam (47.9% and 30.4%, respectively). During 2010-2013, the rates of ESBL-producing E. coli and K. pneumoniae isolates causing community-associated (CA) IAIs (collected <48@?h after admission) were 26.0% and 13.5%, respectively, and those causing hospital-associated (HA) IAIs were 48.0% and 30.6%, respectively. Amikacin, ertapenem and imipenem were the most effective agents against ESBL-producing isolates. Piperacillin/tazobactam displayed good in vitro activity (91.4%) against CA ESBL-producing E. coli. For other commonly isolated Enterobacteriaceae, fluoroquinolones, cefepime and carbapenems exhibited better in vitro activities than third-generation cephalosporins. Amikacin possessed high in vitro activity against all GNB isolates (>80%) causing IAIs, except for Acinetobacter calcoaceticus-baumannii (ACB) complex (30.9% for HA-IAI isolates). All of the antimicrobial agents tested exhibited <45% in vitro activity against ACB complex. Antimicrobial resistance is a persistent threat in the APR and continuous monitoring of evolutionary trends in the susceptibility patterns of GNB causing IAIs in this region is mandatory.