Formulation Prediction for Young's Modulus of Poly(dimethylsiloxane) by Spectroscopic Methods

Cho Han Saem,Moon Heh‐Young,Lee Heung Soon,Kim Yong Tae,Jeoung Sae Chae 대한화학회 2021 Bulletin of the Korean Chemical Society Vol.42 No.9

In this work, we refer to the fraction of hydrides and vinyl groups consumed in cross-linking reaction as a variation of the properties of poly(dimethylsiloxane) (PDMS) with varying the formulation of a curing agent from 3.2 wt % to 50 wt %. Young’s modulus, density, and refractive indices of PDMS were observed to have a maxima at a formulation of about 10 wt % of cross linker. The intensity of the Raman band for the Si H stretching mode in cross-linker is almost zero if the cross-linking agent is less than 10 wt %, but it is linearly increasing with increasing the content of cross-linker. The dependence of the elastic modulus on the formulation could be explained in terms of the fraction of cross-linked network. The analytical framework proposed in this work could be used for optimizing the formulation of PDMS and hence its properties can be tailored for specific applications.

어머니의 신경증적 성향과 완벽주의 및 심리적 통제가 유아의 내면화 문제행동에 미치는 영향

왕해경, 한세영 충북대학교 생활과학연구소 2013 생활과학연구논총 Vol.17 No.1

The purpose of this study was to examine the effects of mother's neuroticism, perfectionism and psychological control on children's internalized problem behaviors such as depression, anxiety, and withdrawal. The subjects of this study were 373 mothers of 3, 4, and 5-years-old children who were attending to 7 public kindergartens and 1 private kindergartens located in Cheongju city. The results of this study were as follows: First, it indicated that mother's neuroticism, self-oriented perfectionism, criticism, and unstable emotion had statistically significant effects on young children's depression. That is, the more neuroticism, the less self-oriented perfectionism, and the more psychological control like criticism and unstable emotion mothers showed, the higher young children's depression was. Second, it revealed that mother's neuroticism and criticism and love withdrawal had statistically significant effects on young children's anxiety. That is, children of mothers with more neuroticism and psychological control like criticism and love withdrawal showed higher anxiety. Third, it was found that only mother's neuroticism had a statistically significant effect on young children's withdrawal. That is, the more neuroticism mothers showed, the higher young children's withdrawal was.

환경농업 시범마을 논에서 시비에 따른 무척추동물 개체 수 변화

한민수,신중두,나영은,이남종,박문희,김세근 한국환경농학회 2002 한국환경농학회지 Vol.21 No.2

논의 관리방법에 따른 수서생물상의 변동 양상을 파악하기 위하여 종합적인 환경농업기술 시범 2개 지역의 논 및 하천에서 주기적으로 조사 분석하였다. 논에서의 수서 무척추동물의 총 개체 수는 두 지역 모두 농가관행구에 비해 화학비료 토양검정 시비구에서 62% 이상 높았고 그 다음은 두 지역에서 서로 다르게 나타나 옥천의 경우 농가관행구, 양평은 화학비료+개량재 순으로 많고, 가장 적은 처리는 무비구였다. 수서곤충의 총 개체 수는 토양검정시비구가 농가관행구 옥천 및 양평 각각 328, 45.1/L보다 56%, 69% 더 많았다. 갑각류의 총 개체수는 옥천 지역에서는 토양검정 화학비료구> 화학 비료+개량제구> 농가관행구> 무비구 순으로 많았으며, 양평에서는 화학비료+개량제구>토양검정 화학비료>무비> 농가관행구 순으로서 과다 비료시용구인 농가관행구에서 가장 적었다. 두 지역의 논관류 하천에서 서식하는 수서 무척추동물은 59과 76종이 분류되었고, 미확인종이 14종으로 조사되었으며, 특히 물방개과 중 노란테 콩알 물방개 및 땅콩 콩알 물방개가 채집되었고 양평 지역에서는 날도래 종류가 다양하게 서식하고 있는 것으로 나타났다. 하천지류별 수서 무척추동물 서식밀도는 두 지역 모두에서 상류보다는 하류에서 밀도가 높았으며, 옥천의 연평균 성적에서도 하류에서 1300/0.09 ㎡로 최상류에 비해 172% 더 많은 밀도를 나타냈다. 친환경 농업 실천 2개 지역에서의 논 서식 수서 무척추동물 개체 수 조사 결과 일반관행 농가 논 91.1/L 보다 58% 더 많았다. This study was conducted to survey and identify kinds and population of the freshwater invertebrate fauna according to the managements of paddy rice fields at Ok-Chun and Yang-Pyung. The experiment was conducted in 4 paddy plots; conventional fertilization plot (CF), fertilization by prescription with soil testing with (ST+A) or without soil amendment (ST), and no fertilization as the control. In addition, the freshwater invertebrate fauna was also surveyed at 3 sections of as upper, intermediate and down, in both Jitan and Bungsan stream. The total number of the freshwater invertebrates was higher in the order of ST>CF>ST+A>C and ST>ST+A>CF>C at Ok-Chun and Yang-Pyung, respectively. The population density of aquatic insects was higher in plots fertilized by prescription with soid testing than in the other plots at both demonstration villages. The freshwater invertebrates collected in Jitan and Bungsan stream were identified and classified into 59 families and 90 species, and their population density was highest in the downstream among.

레진 인레이 합착시 지각과민처리제의 사용이 상아질 결합강도에 미치는 영향

한세희,조영곤 大韓齒科保存學會 2009 Restorative Dentistry & Endodontics Vol.34 No.3

본 연구는 인레이 와동에서 인상을 채득하기 전 지각과민처리제 (Isodan)과 2단계 전부식 접착시스템 (One-Step)과 단일단계 자가부식 접착시스템 (All-Bond SE)으로 처리한 후, 복합레진 인레이를 자가 접착형 레진시멘트인 BisCem으로 합착시키는 경우 레진 인레이의 상아질에 대한 미세인장결합강도와 주사현미경적인 분석을 통하여 비교하였다. 본 연구의 결과, 지각과민처리제인 Isodan만을 사용하는 경우 레진 인레이의 결합강도를 감소시킬 수 있으므로 단독 사용보다는 단일 단계 자가부식 시스템 (All-Bond SE)과 같이 사용하는 것이 추천된다. The purpose of this study was to evaluate the effect of a desensitizer on dentinal bond strength in cementation of composite resin inlay. Fifty four molar teeth were exposed the occlusal dentin. Class I inlay cavities were prepared and randomly divided into six groups. Control group ; no agent, Group 1 ; Isodan, Group 2 ; One-step, Group 3 ; All-Bond SE, Group 4 ; Isodan + One-step, Group 5 : Isodan + All-Bond SE. Desensitizing agent and dentin bonding agents were applied immediately after the completion of the preparations. Impressions were then made. The composite resin inlays (Tescera, Bisco) were fabricated according to the manufacturers' guidelines. Cementation procedures followed a standard protocol by using resin cement(Bis-Cem, Bisco). Specimens were stored in distilled water at 37 ℃ for 24 hours. All specimens were sectioned to obtained sticks with 1.0 × 1.0 mm² cross sectional area. The microtensile bond strength (μTBS) was tested at crosshead speed of 1 mm/min. The data was analyzed using one-way ANOVA and Tukey's test. Scanning electron microscopy analysis was made to examine the details of the bonding interface. 1. Group 1 showed significantly lower μTBS than other groups (p<0.05). 2. There was no significant difference between the μUTB of Group 3 and Group 5. 3. The μTBS of Group 4 showed significantly lower than that of Group 2 (p<0.05). In conclusion, a desensitizer (Isodan) might have an adverse effect on the bond strength of composite resin inlay to dentin.

Paraquat 양이온 기에 대한 전자 스핀 공명 연구

홍세용,박영현,한찬수 순천향대학교 기초과학연구소 1999 순천향자연과학연구 논문집 Vol.5 No.2

Electron spin resonance studies of the radical + 1 cation of paraquat have been carried out at room temperature using X-band microwave. The observed ESR spectra have very complex hyperfine structure due to hyperfine interactions with the nuclei of 2 nitrogens and 14 hydrogens in the radical. The ESR parameters have been found ??, ??, ??, ??, ?? and the hyperfine constants are very close to pervious reports of Janice A. DeGray et. al.

韓國鐵鋼産業의 貿易形態와 國際競爭力에 관한 硏究

金世榮,趙漢姬 단국대학교 산업연구소 1992 산업연구 Vol.15 No.-

폐결핵의 조기진단에 있어서 이중중합효소연쇄반응법의 유용성

조성란,최영진,김용훈,이철세,김영창,김휘준 순천향의학연구소 1998 Journal of Soonchunhyang Medical Science Vol.4 No.2

Background: Pulmonary tuberculosis is a great public health problem in Korea. Early detection of Mycobacterium tuberculosis (M. tuberculosis) in clinical samples becomes more and more important in the control of tuberculosis. Recently, molecular methods have been applied to early detection of M. tuberculosis. Methods: To elucidate the effectiveness of nested polymerase chain reaction (PCR) in early diagnosis of pulmonary tuberculosis, we peformed Acid-fast bacilli (AFB) stain, AFB culture, and nested PCR on 84 sputa. Results: 8 (9.5%) specimens were positive by AFB stain, 17 (20.2%) by AFB culture, and 15 (17.9%) by nested PCR. Using AFB culture as standard method, the sensitivity of AFB stain and nested PCR was 47.1% and 82.4%, respectively. The specificity of AFB stain and nested PCR was 100% and 98.5%, respectively. Conclusions: Nested PCR was more sensitive than AFB stain and had shorter processing time(24-48hrs) than AFB culture. So it may be effective to use nested PCR in order to detect M. tuberculosis when AFB smear Is negative.

근 피판술을 이용한 기관흉막루의 치료

류한영,설정현,김정철,한승세,우상현,최시호 大韓成形外科學會 1991 Archives of Plastic Surgery Vol.18 No.2

Bronchopleural fistula and chronic empyema are the difficult problems in the thoracic surgery field. We experienced 3 cases of chronic empyema and complicated bronchopleural fistulas treated with muscle flap and concomitant thoracoplasty. The causative primary diseases were pulmonary tuberculosis and bronchiectasis. All the three cases have failed to control the chronic empyema and bronchopleural fistula with conventional method such as closed or open drainage and Eloesser flap after lobectomy. The unresponsive infection on bronchopleural fistula and pleural space was well controlled after muscle flap with thoracoplasty. Complete decortication, closure of bronchopleural fistula as much as possible and coverage of closed fistula with good vascularized tissue are the essential factors for the success of operation on chronic empyema and bronchopleural fistula. The results of operations were satisfactory and the respiratory function was well preserved or improved in one patient. But, the contour of chest wall was deformed in patient with extensive concomitant thoracoplasty.

백악질 변연을 갖는 2급 와동에 충전된 4종 복합레진의 미세누출

조영곤,한세희,김은성 대한치과보존학회 2001 Restorative Dentistry & Endodontics Vol.26 No.6

The purpose of this study was to evaluate four different composite resins in vitro for microleakage in Class II box-type restorations that have gingival margins apical to the cementoenamel junction. Forty caries-free extracted human molars were used in this study. The Class II cavities were prepared 1.0mm below cementoenamel junction with a # 701 carbide bur. The teeth were randomly divided into four groups, each group comprising 20 treated cavities according to adhesives and filing materials ; Group 1 : Scotchbond Multipurpose/z-100, Group 2: Ariston Liner/Ariston pHc, Group 3: One-Step/pyramid, Group 4: Prime & Bond NT/SureFil. To simulate the clinical situation during restoration placement, a restoration template was fabricated and composite resin was filled using a three sited light-curing incremental technique. The specimens were stored in the 100% humidity for 7 days prior to thermocycling. The specimens were immersed in 2% methylene blue dye solution for 24 hours and then embeded in transparent acrylic resin and sectioned mesiodistally with a diamond wheel saw. The degree of marginal leakage was scored under the stereomicroscope(×20) and the data were analyzed by Kruskal-Wallis test and Mann-Whitney test. The results were as follows : 1. Microleakage was minimal in the hybrid composite resin type, Z-100. 2. In the condensable types, Pyramid shows the most microleakage compared to Ariston pHc. And SureFil(p<0.001) . 3. There was no statistically significant difference between Ariston pHc and SureFil(p>0.001). Key words : Microleakage, Cemental margin, Hybride composite resin.

95년도 음주운전 교통사고의 분포에 관한 연구

김영운,한백회,민지숙,오세진,박성우 內務部 國立科學搜査硏究所 1996 國立 科學 搜査 硏究所 年報 Vol.28 No.-