An automated longquan celadon glaze thickness measurement method based on optical coherence tomography

Yang Zhou,Longjie Shi,Gang Ceng,Tiebing Liu,Yang Shi,Zhengwei Chen,Fenglin Wang,Yuefeng Ceng 한양대학교 세라믹연구소 2020 Journal of Ceramic Processing Research Vol.21 No.3

The thickness of glaze is one of the important indicators in the quality evaluation of Longquan celadon. But till now, there isno automatic and non-destructive method to measure it. In order to satisfy this demand, an automated method has beenproposed to measure the glaze thickness based on optical coherence tomography (OCT) technique. According to themorphological characteristics of celadon glaze in OCT image, the proposed method locates the upper and lower boundariesof the glaze layer, then the glaze thickness is automatically calculated after the axial resolution calibration of the OCT imagesfor different categories of Longquan celadon. In the experiment, the glaze OCT images of 6 different categories of Longquanceladon were applied in the glaze thickness estimation. By comparing with the physical measuring result, this method is provedto be able to measure the glaze thickness rapidly and non-destructively and the performance is enough to meet the demandof the industrial application.

A QoE-based Joint Bandwidth and Power Allocation Method for Multiple RATs in HetNets

Fan Yang,Qinghai Yang,곽경섭,Fenglin Fu 한국통신학회 2015 ICT Express Vol.1 No.1

In this letter, we propose an optimal joint bandwidth and power allocation method for heterogeneous wireless networks (HetNets) by maximizing the users’ quality of experience (QoE), which is a widely used subjective metric reflecting the users’ satisfaction of the multimedia service. By taking two factors into consideration simultaneously: Rate Factor (RF) and Energy Factor (EF), we can measure the QoE of end-users effectively. An optimal QoE-driven allocation algorithm is further developed for maximizing the end-users’ QoE utility subject to the constraints of transmit bandwidth, power and data rate. The simulation results demonstrate the theoretical analysis.

Outage Performance of Cooperative Relay Using STBC Systems

Yang, Qinghai,Kwak, Kyung Sup,Fu, Fenglin Springer-Verlag 2010 WIRELESS PERSONAL COMMUNICATIONS Vol.52 No.4

Outage Probability of Opportunistic Amplify-and- Forward Relaying in Nakagami-m Fading Channels

Qinghai Yang,Yingji Zhong,곽경섭,Fenglin Fu 한국전자통신연구원 2008 ETRI Journal Vol.30 No.4

We address the outage performance for the opportunistic amplify-and-forward relaying strategies under Nakagami-m fading channels. A closed-form expression for the outage probability is derived. Simulation results verify our theoretical solutions.

Synthesis of Phosphorous Phenanthrene/L-Tryptophan Flame Retardant for Enhanced Flame Retardancy of Epoxy Resins

Li Li,Fenglin Hua,Hui Xi,Jing Yang,Ting Xiao,Rui Zuo,Xueqing Xu,Zhiwang Yang,Ziqiang Lei 한국고분자학회 2022 Macromolecular Research Vol.30 No.12

A new type of phosphorus-containing intrinsic flame retardant was prepared with L-tryptophan (L-Trp) and 9,10-dihydro-9-oxa-10-phosphorbenzophenanthrene- 10-oxide (DOPO) as the main components. The Schiff base from the reaction of 1,4-terephthalaldehyde and L-tryptophan provides active sites, and then the phosphorous compound, DOPO, is successfully introduced into the Schiff base to synthesize L-Trp-DOPO flame retardant. The intrinsic flame retardant property of LTrp- DOPO comes from the reaction of carbonyl groups and the epoxy groups in epoxy resin (EP) matrix. The prepared L-Trp-DOPO flame retardant can efficiently improve the flame retardancy and smoke suppression of the base material of EP. Cone calorimetric test (CCT) of EP/L-Trp-DOPO composite material was carried out. The data showed that the peak heat release rate (pk-HRR) value was reduced by 50.8% (from 1459 kW/m2 to 717 kW/m2), the THR value reduced by 78.3%, and the limiting oxygen index (LOI) value was increased by 24%. The addition of new flame retardant greatly reduced the release of toxic CO gas. The flame retardant mechanism was explored, and it can be found that after thermal decomposition of L-Trp- DOPO a dense carbon layer can be produced to isolate the fire source. In addition, during the combustion process, L-Trp-DOPO will produce phosphorus-containing free radicals which will quench the active free radicals in the gas phase and dilute the combustible gas. The prepared L-Trp-DOPO flame retardant has a flame retardant effect in both the condensed phase and the gas phase during the combustion process.

Flame Retardancy of Epoxy Resin Improved by Graphene Hybrid Containing Phosphorous, Boron, Nitrogen and Silicon Elements

Li Li,Huan Wang,Fenglin Hua,Mingming Wang,Yuanshuo Zhang,Hui Xi,Jing Yang,Zhiwang Yang,Ziqiang Lei 한국고분자학회 2021 Macromolecular Research Vol.29 No.9

An effective ternary organic-inorganic composite flame retardant of reduced graphene oxide-poly-dopamine@graphitic carbon nitride@10-(2,5-dihydroxyphenyl)- 10-H-9-oxa-10-phosphaphenanthrene-10-oxide (RGO-PDA@g-C3N4@ODOPB) was successfully fabricated by co-precipitation method. Its property concerning the intrinsic flame retardancy and the mechanical performance was well studied when it was used as co-additives in combination with ammonium polyphosphate (APP) in epoxy resin (EP) samples. The surface morphology and the structure of RGO-PDA@g-C3N4 @ODOPB were characterized by SEM, and the molecular structure and compositions were investigated by FT-IR, powder XRD and 1H NMR. TGA, limit oxygen index (LOI), vertical burning test (UL-94), cone calorimeter test, and SEM were also used to investigate the thermal properties and flame retardancy of materials. As expected, the flame retardancy of EP was significantly heightened after adding of RGOPDA@ g-C3N4@ODOPB composites. It showed that with the 20% adding of RGO-PDA@g-C3N4@ODOPB/APP into EP led to the decreasing of the peak heat release rate and the total heat release at 78% and 62.5%, respectively. Meanwhile, the LOI value of the EP composites was as high as 29% and reached UL-94 V-0 rate. It was deemed that the excellent flame retardancy was attributed to the forming of compact and stable carbon layer, which was being catalytic carbonization by APP existed in the RGO-PDA@g-C3N4@ODOPB/APP composites. At the same time, the non-combustible gas released from thermal cracking of g-C3N4 during the combustion also benefited the flame retardant performance of EP.

Distinct Inflammatory Profiles in Atopic and Nonatopic Patients With Chronic Rhinosinustis Accompanied by Nasal Polyps in Western China

Luo Ba,Jintao Du,Feng Liu,Sixi Liu,Fenglin Yang,Miaomiao Han,Ping Lin,Huabin Li 대한천식알레르기학회 2015 Allergy, Asthma & Immunology Research Vol.7 No.4

Purpose: The role of systemic sensitization in the pathophysiology of chronic rhinosinusitis with nasal polyps (CRSwNP) remains elusive. This study sought to characterize the pattern of cytokines in polyp tissues from atopic and nonatopic patients with CRSwNP. Methods: Atopic and nonatopic polyp and normal tissues were collected from 70 CRSwNP patients and 26 control subjects, respectively. The distribution of inflammatory cells (eosinophils, neutrophils, mast cells, etc.) were examined using immunohistochemistry, the mRNA levels of the transcription factors GATA-3, T-bet, RORc, and FOXP3 were determined using quantitative real-time polymerase chain reaction. The levels of inflammatory mediators (IFN-γ, IL-5, IL- 17A, etc.) in tissue homogenates were measured using enzyme-linked immunosorbent assay (ELISA). Moreover, the levels of inflammatory mediators in the supernatant of anti-IgE stimulated polyp tissues were measured using ELISA. Results: Atopic CRSwNP patients were characterized by increased eosinophil accumulation, enhanced eosinophilic inflammation (elevated IL-5, ECP, and total IgE), and significantly increased GATA-3 mRNA levels (P<0.05), whereas both atopic and non-atopic CRSwNP patients showed decreased FOXP3 mRNA expression (P<0.05). After addition of anti- IgE stimulation, atopic CRSwNP patients produced more IL-5, IL-2, IL-10, IL-17A, and PGD2 in the supernatant of stimulated polyp tissues than nonatopic CRSwNP patients did. Conclusions: Atopic and nonatopic CRSwNP patients may possess the patterns of inflammatory response in polyp tissues.