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.

Characteristics of 240 Chinese Father-child Pairs with Malignant Disease

Liu, Ju,Li, Ni,Chang, Sheng,Xu, Zhi-Jian,Zhang, Kai Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.11

To obtain a screening and early detection reference for individuals who have a family history of cancer on the paternal side, we collected and analyzed data from 240 pairs in which both fathers and their children were diagnosed with cancer. Disease categories of fathers and sons were similar to that of the general population of China, whereas daughters were different from general female population with high incidence of breast cancer and gynecological cancer. Sons were more likely than daughters to have the same type of cancer, or to have cancer in the same organ system as their fathers (P < 0.0001). Sons and daughters developed malignant diseases 11 and 16 years earlier than their fathers, respectively (P < 0.0001 for both sons and daughters). Daughters developed malignant diseases 5 years earlier than sons (P < 0.0001). Men with a family history of malignant tumors on the paternal side should be screened for malignancies from the age of 45 years, or 11 years earlier than the age of their fathers' diagnosis, and women should be screened from the age of 40 years, or 16 years earlier than the age at which their fathers were diagnosed with cancer. Lung cancer should be investigated in both men and women, whilst screening should focus on cancer of the digestive system in men and on breast and gynecological cancer (ovary, uterine and cervical cancer) in women.

Exogenous p53 Upregulated Modulator of Apoptosis (PUMA) Decreases Growth of Lung Cancer A549 Cells

Liu, Chun-Ju,Zhang, Xia-Li,Luo, Da-Ya,Zhu, Wei-Feng,Wan, Hui-Fang,Yang, Jun-Ping,Yang, Xiao-Jun,Wan, Fu-Sheng Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.2

Purpose: To investigate the influence of exogenous p53 upregulated modulator of apoptosis (PUMA) expression on cell proliferation and apoptosis in human non-small cell lung cancer A549 cells and transplanted tumor cell growth in nude mice. Materials and Methods: A549 cells were divided into the following groups: control, non-carrier (NC), PUMA (transfected with pCEP4-(HA) 2-PUMA plasmid), DDP ($10{\mu}g/mL$ cisplatin treatment) and PUMA+DDP (transfected with pCEP4-(HA)2-PUMA plasmid and $10{\mu}g/mL$ cisplatin treatment). The MTT method was used to detect the cell survival rate. Cell apoptosis rates were measured by flow cytometry, and PUMA, Bax and Bcl-2 protein expression levels were measured by Western blotting. Results: Compared to the control group, the PUMA, DDP and PUMA+DDP groups all had significantly decreased A549 cell proliferation (p<0.01), with the largest reduction in the PUMA+DDP group. Conversely, the apoptosis rates of the three groups were significantly increased (P<0.01), and the PUMA and DDP treatments were synergistic. Moreover, Bax protein levels significantly increased (p<0.01), while Bcl-2 protein levels significantly decreased (p<0.01). Finally, both the volume and the weights of transplanted tumors were significantly reduced (p<0.01), and the inhibition ratio of the PUMA+DDP group was significantly higher than in the single DDP or PUMA groups. Conclusions: Exogenous PUMA effectively inhibited lung cancer A549 cell proliferation and transplanted tumor growth by increasing Bax protein levels and reducing Bcl-2 protein levels.

A Parallel Fast Sort Algorithm for Mass 3D Point Clouds of Irregular Model

Liu Yan-ju,Zhang Hong-lie,Tao Bai-rui,Li Cheng 보안공학연구지원센터 2015 International Journal of Multimedia and Ubiquitous Vol.10 No.6

According to mass point clouds without explicit topology relation, a parallel fast sort algorithm is proposed in this paper. Morton order is introduced and used to merge one-dimensional data. The mass point clouds of irregular model are generated corresponding address code named Morton code and these points are stored in the octree structure chain. And then a parallel fast sort algorithm based on Euclidean distance is used to sort by CPU and GPU. The k-Nearest Neighbors of point can be located in the chain. The experiment results show that much time is saved and k-Nearest Neighbors of point can be searched directly. This algorithm is simpler than those complex sort methods used on the whole point clouds.

Antioxidative Activities of Kefir

Liu, Je-Ruei,Lin, Yuh-Yih,Chen, Ming-Ju,Chen, Li-Ju,Lin, Chin-Wen Asian Australasian Association of Animal Productio 2005 Animal Bioscience Vol.18 No.4

This study aims to evaluate the antioxidative activities of cow-milk kefir and goat-milk kefir. Antioxidative mechanisms, including radical-scavenging effects, ferrous-ion chelating ability, reducing power and antioxidant activity, were investigated herein. Kefirs demonstrated significantly greater scavenging effects upon 1,1-diphenyl-2-picrylhydrazyl (DPPH) and superoxide radicals, an inhibition effect upon linoleic-acid peroxidation, and more substantial reducing power, but reduced glutathione peroxidase (GSH-Px) activity than was the case for milks. There was no significant difference between milks and kefirs as regards ferrous-ion chelating ability and superoxide dismutase (SOD) activity. These findings have demonstrated that kefirs possess antioxidant activity, thereby suggesting that kefirs are potential candidates for the role of useful natural antioxidant supplements for the human diet.