PTMG-PU와 PEAG-PU의 중합에 미치는 합성온도 영향

류주환,김수동 忠南大學校 産業技術硏究所 1998 산업기술연구논문집 Vol.13 No.2

예비고분자 방법을 이용하여 PTMG-PU와 PEAG-PU를 합성하였다. PTMG-PU와 PEAG-PU에서 합성온도를 올림에 따라 가교결합 증가와 상분리 감소를 적외선 분광기를 이용하여 확인하였다. 또한 합성온도 상승의 영향은 DSC에 의해 확인되었다. 가교결합의 증가와 상분리의 감소는 PTMG-PU와 PEAG-PU의 유리전이 상승을 초래하였다. 적외선 분광기와 DSC로 확인한 중합온도 영향이 분자 구조적인 면에서 같다 할지라도 PTMG-PU와 PEAG-PU의 인장강도와 연신율은 반대로 나타났다. 이것은 가교밀도의 변화에 의한 것으로 고찰되었다. We synthesized PTMG-PU and PEAG-PU through prepolymer method. According to IR, we observed that as the reaction temperature increases, crosslinking density was increased and phase seperation was decreased in both cases of PTMG-PU and PEAG-PU. Also the synthesis temperature increasing effect was confirmed by DSC. Increase in crosslinking density and decrease in phase seperation resulted in the increase of glass transition temperature in both PTMG-PU and PEAG-PU. Althouth the synthesis temperature effect was the same in molecular structure variation, tensile and elongation properties of PTMG-PU and PEAG-PU were reverse. This was discussed in terms of the crosslinking density.

PMMA 공중합체의 미세구조 분석

류주환 충남대학교 산업기술연구소 2003 산업기술연구논문집 Vol.18 No.1

The microstructure of polymers plays an important role in governing their properties. In the case of copolymers, the number of structural variables usually increases to such an extent that the detailed characterization becomes very difficult. However, NMR spectroscopy provides a powerful tool in elucidating the microstructures. In this study we investigated the structure of the a series of copolymer prepared from methyl methacrylate and methyl acrylate. Various NMR techniques were applied to fully understand the NMR spectral features of the samples. Then the reactivity ratios and tacticity and cotacticity parameters were rigorously deduced from the NMR spectral data.

PAN Unit의 단일중합체와 공중합체에서의 배향에 관한 연구

박해랑,류주환 충남대학교 산업기술연구소 2003 산업기술연구논문집 Vol.18 No.1

Polyacrylonitrile(PAN) is a well-known crystalline polymer. Even when PAN is in its atactic configuration, as is usual, the crystallinity still strongly persists. This is due to the strong interaction between the nitrile groups. Hence much interest has been focused on the elucidation of the conformation of PAN. However, a full agreement on the crystalline morphology and the conformational state of individual polymer chains is yet to be achieved. In this study, we used as samples a PAN homopolymer and an AN-methyl acrylate(MA) copolymer. In the latter, MA is considered as a way of introducing a slight structural perturbation to the AN sequence in the homopolymer. Then the infrared dichroism technique was used to follow the behavior of orientation as a function of the extension. In carrying out these experiments, detailed considerations on the conformational structure of the PAN chains were given on the molecular basis. As a result, we found that the orientation behavior of the unperturbed AN sequences was more sensitive to the extension and its linearity of the chains was higher than the perturbed counterpart, in good agreement with the conjecture on the molecular level.

RO 및 NF막에서의 부식질에 의한 Fouling 및 미량오염물질의 제거

왕창근,차준철,이용현,김수동,류주환 대한상하수도학회 2004 상하수도학회지 Vol.18 No.1

This study investigated the phenomena of membrane fouling by NOM and the effect of the fouling on removal of micro-pollutants. NOM has a great effect on decline of permeate flux. Permeate flow rate was reduced by 88% in RO and 34.8% in NF for 323hr operation period. Removal rate of UV_(254), is 87.4% in RO and 78.5% in NF and removal rate of DOC is 42.7% in RO and 32.9% in NF for 2㎎/l humic acid. Removal efficiency of the micmpollutants by the RO and NF membranes fouled by humic acid was mostly lower than that by the new membrane. The concentration polarization which affects the flux and the rejection was thought to occur in the active layer of the membrane, as the membrane was getting fouled.

Hybrid Patterns Recognition of Control Chart Based on WA-PCA-PSO-SVM

Liu Yan-zhong,Zhang Hong-lie,Liu Yan-ju,Jiang Jin-gang 보안공학연구지원센터 2014 International Journal of Control and Automation Vol.7 No.10

Based on the analysis of the defect of traditional model, this paper proposes a new control chart pattern recognition model, which includes Wavelet Analysis (WA), Principal Component Analysis (PCA), Particle Swarm Optimization (PSO) and Support Vector Machine (SVM). WA is good to eliminate noise control chart anomaly pattern recognition of the adverse effect. PCA eliminates the redundant information of data between SVM and reduces the input dimension and computational complexity. PSO algorithm optimizes the parameters of SVM and the establishment of the optimal control chart anomaly pattern classifier can solve the problem optimal parameters of SVM. The simulation results show that the model is feasible, the results are reliable. This algorithm improves the control chart abnormal state average recognition accuracy and be used in the machining process real-time monitoring.

Rapid HPLC determination of gastrodin in Gastrodiae Rhizoma

Lee, Ju-Gyeong,Moon, Sung-Ok,Kim, Se-Yong,Yang, Eun-Ju,Min, Ju-Sik,An, Ju-Hee,Choi, Eun-A,Liu, Kwang-Hyeon,Park, Eun Ji,Lee, Hwa-Dong,Song, Kyung-Sik 한국응용생명화학회 2015 Applied Biological Chemistry (Appl Biol Chem) Vol.58 No.3

Gastrodin is a major biologically active ingredient in members of the genus Gastrodia. For this reason, there are many reports on the quantification of gastrodin in Gastrodiae Rhizoma (GR) and in GR-containing herbal preparations. HPLC, HPLC-MS, and TLC are the major approaches for gastrodin quantification; however, they usually require complicated pre-treatment, lengthy analysis, and expensive instruments. Therefore, a rapid and reliable method for determining gastrodin in GR is necessary. Optimal HPLC separation was achieved using a Chromolith Performance RP-18e ($4.8{\times}100mm$, $5{\mu}m$) stationary phase. The optimal mobile phase was a mixture of water (A) and acetonitrile (B) with a gradient of 1 % B at 0-8 min, 20 % B at 8-10 min, 80-100 % B at 10-12 min, and 100 % B at 12-13 min, followed by equilibration with 1 % B for 2 min at a flow rate of 1.5 mL/min. The detection wavelength was UV220 nm. Gastrodin appeared within 4 min under the above conditions. The calibration curve of gastrodin showed good linearity in the 0.25-10.0 range ($r^2=0.9998$). The limit of detection ($0.13{\mu}g$), limit of quantification ($0.25{\mu}g$), and reproducibilities of area and retention time (0.04 and 3.24 %, respectively) were within acceptable ranges. In addition, the intra-day precision and accuracy of gastrodin were 0.74 and $100.63{\pm}0.04%$, respectively, while the inter-day precision and accuracy were 0.06 and $99.25{\pm}0.05%$, respectively. The range of mean gastrodin content in six GR samples, which were cultivated at different sites, was 0.37-0.79 %. This result may be a guideline for the quality control of GR and GR-containing medicinal preparations.

A Novel Self-Organized Fuzzy Neural Network Surface Reconstruction Algorithm for Point Clouds Without Normal

Liu Yan-ju,Liu Yan-zhong,Tao Bai-rui,Jiang Jin-gang,Zhang Hong-lie 보안공학연구지원센터 2014 International Journal of Database Theory and Appli Vol.7 No.4

Normal Estimation for Mass Point Clouds of Irregular Model in the 3D Reconstruction based on Fuzzy Inference

Liu Yan-ju,Jiang Jin-gang,Miao Feng-juan,Tao Bai-rui,Zhang Hong-lie 보안공학연구지원센터 2014 International Journal of Grid and Distributed Comp Vol.7 No.5

This paper presents a fuzzy normal estimate for mass point clouds of irregular models in reconstruction. The irregular model is complex object that some part is smooth and some parts are irregular including sharp features. Therefore, we put kNN and curvature of mass point clouds to fuzzy inference system to divide the kind of point clouds and the output of FIS can determine which part of tooth point clouds belong to. For different kinds point clouds, corresponding algorithm is given. Point clouds in the smooth area are estimated normal by PCA directly and ones in other regions of thin or sharp area are estimated by checker and attach points. This method is simpler than those complex methods used on the whole point clouds directly. The experiment results show that much time is saved and surface reconstruction is very fine than PCA and WLOP.

Semaphoring mAb: a New Guide in RIT in Inhibiting the Proliferation of Human Skin Carcinoma

Liu, Yuan,Ma, Jing-Yue,Luo, Su-Ju,Sun, Chen-Wei,Shao, Li-Li,Liu, Quan-Zhong Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.3

Semaphoring is a transmembrane receptor which participates in many cytokine-mediated signal pathways that are closely related to the angiogenesis, occurrence and development of carcinoma. The present study was designed to access the effect of mono-antibody (mAb) guided radioimmunotherapy (RIT) on skin carcinoma and investigate the potential mechanisms. Semaphoring mAb was acquired from mice (Balb/c), purified with rProtein A column; purity, concentration and activity were tested with SDS-PAGE and indirect ELISA; specificity and expression on the cutanuem carcinoma line and tissue were tested by Western blotting; morphology change was assessed by microscopy. MTT assay and colony inhibition tests were carried out to test the influence on the proliferation of tumor cells; Western blotting was also carried out for expression of apoptosis-associated (caspase-3, Bax, Bcl-2) and proliferation-related (PI3K, p-Akt, Akt, p-ERK1/2, ERK1/2) proteins and analyse the change in signal pathways (PI3K/Akt and MEK/ERK). The purity of purified semaphorin mAb was 96.5% and the titer is about $1{\times}10^6$. Western blotting showed semaphoring mAb to have specifically binding stripes with semaphoring b1b2 protein, B16F10, and A431 cells at 39KDa, 100KDa and 130KDa, respectively. Positive expression was detected both in cutanuem carcinoma line and tissue and it mostly located in cell membranes. MMT assay revealed dose-relate and time-relate inhibitory effect of semaphorin mAb on A431 and B16F10. Colony inhibition tests also showed dose-relate inhibitory effects. Western blotting demonstrated the expression of apoptosis and proliferation-related protein and changes in signal pathway. In conclusion, we demonstrated that semaphorin is highly expressed on the tumor cell-surfaces and RIT with semaphorin mAb has effect in i nhibiting proliferation and accelerating apoptosis of tumor cells.

Reduction Strategy of Point Clouds to Reconstruct Surface Based on Fuzzy Clustering

Liu Yan-ju,Jiang Jin-gang,Tao Bai-rui,Zhang Hong-lie,Liu Yan-zhong 보안공학연구지원센터(IJGDC) 2014 International Journal of Grid and Distributed Comp Vol.7 No.4