• Title/Summary/Keyword: end group effect

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UV-Curable Fluorinated Crosslinkable Polyurethane-Acrylates for Marine Antifouling Coatings

  • Park, Jin-Myung;Kim, Sung Yeol;An, Seung-Kook;Lee, Young-Hee;Kim, Han-Do
    • Clean Technology
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    • v.23 no.2
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    • pp.148-157
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    • 2017
  • To prepare UV-curable polyurethane-acrylate oligomer, NCO-terminated urethane prepolymers with trimethylolpropane, [TMP; 0 (0), 0.1 (0.021) and 0.2 (0.043) mole (mole fraction)] as crosslinkable tri-functional chain extender were end-capped with pentaerythritol triacrylate [PETA; 2.0 (0.400), 1.7 (0.354) and 1.4 (0.304) mole (mole fraction)] with one hydroxyl group/three vinyl functionalities. The stable as-formulated UV-curable polyurethane-acrylates [stable mixtures of PETA-capped oligomer/reactive acrylic monomer diluents without/with heptadecafluorodecyl methacrylate (PFA; 0, 6 and 9 wt%)] were formed up to 0.2 (0.043) mole (mole fraction) of TMP content in the prepolymer, while homogeneous-mixing failed at 0.3 (0.068) mole (mole fraction), in which the crosslink density in NCO-terminated urethane prepolymer was too high to enable the formation of stable mixture. This study examined the effect of TMP/PETA molar ratio and heptadecafluorodecyl methacrylate (PFA) content (wt%) on the properties of UV-cured polyurethane-acrylates as marine antifouling coating materials. The properties of UV-cured polyurethane-acrylate were found to be significantly dependent on the crosslinkable TMP/PETA ratio and PFA content. With the increasing of the TMP and PFA contents, the contact angles increased, and consequently the surface tension decreased. The adhesion of algae/barnacles to PFA contained film samples were found to be sufficiently weak to allow their easy removal. These results suggest that the UV-cured samples containing PFA have strong potential as coating materials for antifouling applications.

A Study on the Expressive Characteristics of Czech Cubism's furniture Design - chiefly focusing on mutual relationship with Czech Cubism's painting, craft, and architecture (체코 큐비즘 가구디자인에 나타난 표현특성에 관한 연구 - 회화, 공예, 건축과의 상호연관성을 중심으로 -)

  • Choi Byung Hoon;Kim Jin Woo
    • Korean Institute of Interior Design Journal
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    • v.14 no.3 s.50
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    • pp.165-172
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    • 2005
  • Cubism is a style that led the way to proclaim a new era of 20th century's art and contemporarily had an influence on several trends of thoughts. Geographically it formed Czech Cubism exerting an effect upon thoughts and plastic art of the progressive art group which showed activity around Prague, Czech in 1911, later for 10 years, it was developed as an unique form of which origin cannot be traced inside and outside Europe and expressed its own plastic art world in craft, furniture, painting, architecture, etc. The object of this study is to pull out the expressive characteristics showed especially in furniture design among Czech Cubism around interrelationship with painting, craft and architecture. The scope of study is to bring out the characteristics about the examples which 7 designers such as Josef Gocar, Pavel Janak, etc., who were representative designers of furniture design of Czech Cubism for 15 years from 1910 to 1925. The method of study is to investigate the origin of Czech Cubism by means of primitive elements of Africa, traces of Islamic architectures, and Czech traditional architectural motive, and the development process of Czech Cubism was arranged around the artist and exhibitions which led this current. After being synthesized the characteristics showed in painting, craft, architecture of Czech Cubism on the basis of the result of this study, the expressive characteristics of furniture design of Czech Cubism were brought out. As a result, the expressive characteristics of furniture design of Czech cubism are indicated in a large way as follow; 1) symbolic characteristic based on primitive plastic art, 2) dynamic characteristic by dividing form, 3) ethnic decorative characteristic combined with national motive. The significance of furniture design of Czech Cubism is not only to accept positively and digest the progressive trend of modern art, that is to say, Paris Cubism but also to succeed in recreate it in its own national style, to play a role to offer another motive to post modern design development at the end of 20th century and by means of these examples to provide the necessity and the base of more profound study in the future.

Evaluation of Maternal Toxicity in Rats Exposed to Multi-Wall Carbon Nanotubes during Pregnancy

  • Lim, Jeong-Hyeon;Kim, Sung-Hwan;Lee, In-Chul;Moon, Chang-Jong;Kim, Sung-Ho;Shin, Dong-Ho;Kim, Hyoung-Chin;Kim, Jong-Choon
    • Environmental Analysis Health and Toxicology
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    • v.26
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    • pp.6.1-6.8
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    • 2011
  • Objectives: The present study investigated the potential adverse effects of multi-wall carbon nanotubes (MWCNTs) on pregnant dams and embryonic development following maternal exposure in rats. Methods: MWCNTs were orally administered to pregnant rats from gestational day (GD) 6 through 19 at dose levels of 0, 8, 40, 200, and 1000 mg/kg/day. During the test period, clinical signs, mortality, body weights, food consumption, serum biochemistry, oxidant-antioxidant status, gross findings, organ weights, and Caesarean section findings were examined. Results: All animals survived to the end of the study. A decrease in thymus weight was observed in the highest dose group. However, maternal body weight, food consumption, serum biochemical parameters, and oxidant-antioxidant balance in the kidneys were not affected by treatment with MWCNTs. No treatment-related differences in gestational index, embryo-fetal mortality, or fetal and placental weights were observed between treated and control groups. Conclusions: The results show that 14-day repeated oral dosing of MWCNTs during pregnancy induces minimal maternal toxicity at 1000 mg/kg/day in rats. Under these experimental conditions, the no-observed-adverse-effect level of MWCNTs is considered to be 200 mg/kg/day for dams and 1000 mg/kg/day for embryonic development.

Effect of Spicy Food on Face Image Color According to Sasang Constitution (사상체질에 따른 매운 음식이 얼굴 색상에 미치는 영향)

  • Ka, Min-Kyoung;Kim, Mi-Hye;Kim, Bong-Hyun;Kim, Hee-Dai;Cho, Dong-Uk
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.5
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    • pp.2671-2677
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    • 2014
  • These days, there is increasing those who like spicy food, people release stress by eating spicy food. But, when you eat spicy food, there is a difference but, we visually can be found red facial color to change. In this paper, when you eat spicy food, we carried out experiment which comparison and analysis color change of facial area depending on Sasang constitutional type. To this end, we organized test subject group by Sasang constitutional type according to survey result for Sasang constitutional type. And then we carried out interrelationship analysis between spicy food and facial color depending on facial color to apply Lab color system based on facial image which is before and after eat a hot spicy pepper.

The Effect of Student-Generated Questions Partially Applied in a Pathology Course on Learning Motivation, Communication, and Problem Solving of Nursing Students (병리학 교과목에 부분 적용한 학습자질문중심학습법이 간호대학생의 학습동기, 의사소통, 문제해결능력에 미치는 효과)

  • Ryu, Young Mi;Oh, Seieun
    • Journal of Digital Convergence
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    • v.17 no.3
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    • pp.331-340
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    • 2019
  • The purpose of this study was to examine the effects of student-generated questions (SGQs) partially applied in a pathology course on learning motivation, communication abilities, and problem-solving skills in nursing students. A one-group pretest-posttest design was employed to conduct this study with 106 nursing students taking the pathology course in a university-setting. Data were analyzed using a Wilcoxon signed-rank test in SPSS version 20. The results showed that communication and problem-solving skills were significantly improved at the end of the semester compared to the beginning. The findings imply that SGQs could be an effective means to improve nursing students' skills of communication and problem solving. To equip nursing students with such core competencies, teaching-learning methods combined various strategies should be developed and applied to nursing education.

High Density Lipoprotein from Egg Yolk (EYHDL) Improves Dyslipidemia by Mediating Fatty Acids Metabolism in High Fat Diet-induced Obese Mice

  • Yu, Zhihui;Mao, Changyi;Fu, Xing;Ma, Meihu
    • Food Science of Animal Resources
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    • v.39 no.2
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    • pp.179-196
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    • 2019
  • We investigated the effect of high density lipoprotein from egg yolk (EYHDL) on serum, hepatic and fecal lipid and fatty acids (FAs) levels and on gene expression involved in FAs metabolism. Male KM mice were fed either normal diet (ND; n=20), high fat diet (HFD; n=20), or high fat diet containing EYHDL (EYHDL; 0.6 mg/g, every day by oral gavage, n=20) for 100 days. At the end of the experiment, the effects of treatments on biochemical parameters, FAs profiles and involved gene expression were analyzed. Our results revealed that EYHDL markedly suppressed the body weight gain, accumulation of abdominal fat tissues, serum concentrations of LDL-cholesterol (LDL-C) and triglycerides, hepatic triglycerides and cholesterol accumulation, while increased serum concentration of HDL-cholesterol (HDL-C). EYHDL intake also increased total cholesterol (TC) excretions compared with HFD group. Moreover, it alleviated the severity of fatty liver and improved glucose and insulin tolerance compared with HFD. More importantly, EYHDL partially normalized FAs profiles in serum, liver and fecaces and neutralized the HFD-induced upregulation of SREBP-1c, Acaca, Fasn, GPAT and Scd1. In conclusion, our findings indicate that EYHDL may have the potential to improve metabolic disturbances that occur in HFD mice and can be considered as an appropriate dietary recommendation for the treatment of metabolic syndrome (MetS).

Field test and research on shield cutting pile penetrating cement soil single pile composite foundation

  • Ma, Shi-ju;Li, Ming-yu;Guo, Yuan-cheng;Safaei, Babak
    • Geomechanics and Engineering
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    • v.23 no.6
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    • pp.513-521
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    • 2020
  • In this paper, due to the need for cutting cement-soil group pile composite foundation under the 7-story masonry structure of Zhenghe District and the shield tunnel of Zhengzhou Metro Line 5, a field test was conducted to directly cut cement-soil single pile composite foundation with diameter Ф=500 mm. Research results showed that the load transfer mechanism of composite foundation was not changed before and after shield tunnel cut the pile, and pile body and the soil between piles was still responsible for overburden load. The construction disturbance of shield cutting pile is a complicated mechanical process. The load carried by the original pile body was affected by the disturbance effect of pile cutting construction. Also, the fraction of the load carried by the original pile body was transferred to the soil between the piles and therefore, the bearing capacity of composite foundation was not decreased. Only the fractions of the load carried by pile and the soil between piles were distributed. On-site monitoring results showed that the settlement of pressure-bearing plates produced during shield cutting stage accounted for about 7% of total settlement. After the completion of pile cutting, the settlements of bearing plates generated by shield machine during residual pile composite foundation stage and shield machine tail were far away from residual pile composite foundation stage which accounted for about 15% and 74% of total settlement, respectively. In order to reduce the impact of shield cutting pile construction on the settlement of upper composite foundation, it was recommended to take measures such as optimization of shield construction parameters, radial grouting reinforcement and "clay shock" grouting within the disturbance range of shield cutting pile construction. Before pile cutting, the pile-soil stress ratio n of composite foundation was 2.437. After the shield cut pile is completed, the soil around the lining structure is gradually consolidated and reshaped, and residual pile composite foundation reaches a new state of force balance. This was because the condensation of grouting layer could increase the resistance of remaining pile end and friction resistance of the side of the pile.

Dragon fruit (Hylocereus undatus) peel pellet as a rumen enhancer in Holstein crossbred bulls

  • Matra, Maharach;Totakul, Pajaree;Viennasay, Bounnaxay;Phesatcha, Burarat;Wanapat, Metha
    • Animal Bioscience
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    • v.34 no.4
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    • pp.594-602
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    • 2021
  • Objective: An experiment was conducted to assess the effect of dragon fruit peel pellet (DFPP) as a rumen enhancer of dry matter consumption, nutrient digestibilities, ruminal ecology, microbial protein synthesis and rumimal methane production in Holstein crossbred bulls. Methods: Four animals, with an average live-weight of 200±20 kg were randomly assigned in a 4×4 Latin square design to investigate the influence of DFPP supplementation. There were four different dietary treatments: without DFPP, and with 200, 300, and 400 g/h/d, respectively. Results: Results revealed that dry matter consumption of total intake, rice straw and concentrate were not significantly different among treatments (p>0.05). It was also found that ruminal pH was not different among treatments (p>0.05), whilst protozoal group was reduced when DFPP increased (p<0.01). Blood urea nitrogen and NH3-N concentrations were increased at 400 g of DFPP supplementation (p<0.01). Additionally, volatile fatty acid production of propionate was significantly enhanced by the DFPP supplementation (p<0.05), while production of methane was consequently decreased (p<0.05). Furthermore, microbial protein synthesis and urinary purine derivatives were remarkably increased especially at 400 g of DFPP supplementation (p<0.05). Conclusion: Plant secondary compounds or phytonutrients (PTN) containing saponins (SP) and condensed tannins (CT) have been reported to influence rumen fermentation. DFPP contains both CT and SP as a PTN. The addition of 400 g of DFPP resulted in improved rumen fermentation end-products especially propionate (C3) and microbial protein synthesis. Therefore, DFPP is a promising rumen enhancer and indicated a significant potential of DFPP as feedstuff for ruminant feed to mitigate rumen methane production.

Chuna Manual Therapy for Carpal Tunnel Syndrome: A Systematic Review (손목 터널 증후군에 대한 추나요법의 효과: 체계적 문헌 고찰)

  • Park, Sun-Young;Lee, Sang-Hyun;Heo, In;Hwang, Eui-Hyoung
    • The Journal of Churna Manual Medicine for Spine and Nerves
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    • v.16 no.2
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    • pp.9-19
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    • 2021
  • Objectives This systematic review aimed to provide evidence for the effectiveness and safety of Chuna manual therapy (CMT) for carpal tunnel syndrome (CTS). Methods We searched 12 electronic databases (PubMed, Ovid-MEDLINE, EMBASE, The Cochrane Library, CNKI, CiNii, ScienceON, KMbase, KISS, OASIS, KMTANK, and RISS) up to the end of October 2021. We only included randomized controlled trials (RCTs) investigating CMT for the treatment of CTS. The methodological quality of the included RCTs was evaluated using the Cochrane Risk of Bias Tool 1.0. Results Six RCTs were eligible for inclusion in our study. A meta-analysis of four studies demonstrated positive results for the use of CMT when used in conjunction with Korean medicine treatment compared to those for Western conservative treatment for CTS. Conjunction treatment significantly improved the total efficacy rate compared to conservative treatment alone (P=0.0007, n=4). Conclusions There is reliable evidence for the use of CMT in treating CTS based on a published meta-analysis. To measure only the effect of Chuna, an experimental group should be designed with Chuna alone to evaluate its effectiveness. However, it should be noted that the studies included in this systematic review were heterogeneous and of low quality, thus warranting further investigation using well-designed RCTs.

The Effects of Self-directed Learning Program to Improve Learning Initiative on Academic Self-efficacy and Self-directed Learning Ability (학습주도성 향상을 위한 자기주도학습 프로그램이 학업적 자기효능감과 자기주도학습 능력에 미치는 효과)

  • Kim, Kyeong-Hee
    • The Journal of the Korea Contents Association
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    • v.22 no.10
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    • pp.816-826
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    • 2022
  • The purpose of this study is to examine the effect of improving academic self-efficacy and self-directed learning ability by conducting a self-directed learning program for college students. To this end, a program was conducted for 28 college students. In order to examine the effectiveness of the program, a single-group pre-post design method was used, which compared the pre-score before the program and the post-score after the program. The program was conducted during the 8 session. The research results are as follows. First, the pre-post scores of the academic self-efficacy of the students who participated in the program increased, but it was not statistically significant. Second, the pre-post score of the self-directed learning ability of students who participated in the self-directed learning program increased significantly. Through these results, the implications of the self-directed learning program for college students and suggestions for follow-up research were presented.