• 제목/요약/키워드: early ages

검색결과 752건 처리시간 0.027초

EVA와 초조강시멘트를 사용한 폴리머 시멘트 슬러리 도장철근의 부착강도에 관한 연구 (A Study on the Bond Strength of Coated Rebar by Polymer Cement Slurry Made of EVA and Ultra High-Early Strength Cement)

  • 형원길;조영국
    • 콘크리트학회논문집
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    • 제27권6호
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    • pp.633-640
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    • 2015
  • 본 연구는 EVA와 초조강시멘트로 만든 폴리머 시멘트 슬러리(PCS)로 도장한 도장철근의 부착강도 개선에 영향을 미치는 PCS 도장재 배합에 관한 연구로 도장두께, 폴리머 시멘트비, 도장재의 양생재령을 변화시켜 배합을 설정하여 부착강도 시험을 실시하였다. 본 연구결과, PCS 도장철근의 부착강도는 거의 모든 배합에서 도장하지 않은 보통철근 및 에폭시철근에 비해 높은 부착강도를 나타냈는데 도장철근의 최대 부착강도는 보통철근에 비해 1.32배, 에폭시철근에 비해 1.38배 높게 나타났다. 도장두께는 대체로 얇은 도장두께인 $75{\mu}m$$100{\mu}m$에서 부착강도가 높게 나타났으며 폴리머 시멘트비에 따른 영향은 크게 나타나지 않았으나, 내구성면에서 폴리머 시멘트비를 80~100% 범위를 확보하는 것을 제안할 수 있었다. 또한 도장재의 양생재령에 있어서는 7일에서 가장 높은 부착강도를 나타냈으나, 재령 1일에 있어서도 보통철근과 에폭시철근에 비해 높은 부착강도를 보여 현장 시공성 측면에서 1일 재령을 제안 할 수 있었다.

서양 남성의 나이트클로즈에 관한 고찰 (A Study on the Western Men′s Nightclothes)

  • 김주애
    • 복식문화연구
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    • 제8권2호
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    • pp.205-216
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    • 2000
  • The purpose of study examined of historical changes of western men's nightclothes from middle ages to the modern ages and analyzed functions and features of men's nightclothes. This study presented meaning and importance of men's nightclothes. The method of study researched the many literatures and internet sources. Until medieval age, men slept naked or in a day-shirt. In the 16th century, a nightshirt was worn in bed. A night-cap was usual, in rather more elaborate form, also worn by day in the house, and even outdoors. In the 17th century, nightshirt was elabrated with ruffles and lace. The nightshirts of 18th century, resembled the day-shirt except that it was slightly longer and fuller in cut. The turn of 19th century, men weared nightshirt with a high folding collar, one button and night-cap of jellybag shape. In the early 19th century, nightshirt had a plain turned-down collar, buttoned at the neck. A night-cap with colored tassel was usual. The middle of 19th century, a nightgown was reaching to the ankle. Pyjamas, in the 1890s, were steadily replacing the nightshirt, before long pyjamas had become generally accepted in place of the nightshirt. A pyjamas which preseverved his male dignity by giving him trousers. Man's ingenuity also modified his nigntclothes so that these took on sexual characteristic. In 20th century, the fabrics had become lighter in weight, and the choice of materials wider. By 1930s, nightclothes had become the man's most colorful garment.

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호남 전단대내에 분포하는 엽리상화강암류의 지질시대와 생성과정에 관한 연구 (The Study on Geochronology and Petrogenesis of Foliated Granites in the Honam Shear Zone, South Korea)

  • 김용준;박영석;강상원
    • 자원환경지질
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    • 제27권3호
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    • pp.247-261
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    • 1994
  • Honam Shear Zone is a mylonite zone approximately parallel to the NE-SW trend located southern part of Korea peninsula. Geologic ages and petrogenesis of foliated granites in this zone are as follows: Igneous rocks of this zone are composed of granite gneiss, Paleozoic granites, Songrim granites, Jurassic granites and Cretaceous granites. Foliated granites show deformed phase of Paleozoic and Songrim granites during Daebo Orogeny. And isotopic ages obtained from foliated granites are early Permian to late Triassic period (276~200 Ma). Most of foliated granite masses are igneous complex consisting of a series of differential product of cogenetic magma. The individual rock mass of foliated granites plotted on Harker diagram shows mostly similar trend of calc-alkali series. REE diagram indicates that LREE amount of foliated granites are more enriched than HREE and negative Eu anomalies of them are weaker than those of the other granites. From these data, we suggest the rocks are generated from continental margin under syntectonic environment. Original magma type of foliated granites correspond to I-type, syn-collision type and Hercyano type. In compressive stress field between Ogcheon folded belt and Youngnam massif, foliated granites had formed due to mylonitic deformation. Those facts indicate that magma of foliated granites would had been generated by melting in lower crust or contamination in upper mantle.

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THE H$\beta$ INDEX AND THE AGES OF OLD STELLAR SYSTEMS

  • Yoon, Seok-Jin;Lee, Hyun-Chul;Lee, Young-Wook
    • Journal of Astronomy and Space Sciences
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    • 제15권1호
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    • pp.53-58
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    • 1998
  • The $H{\beta}$ and some metal line indices, such as Mg2, Fe52 of single-age and single-metallicity populations are computed based on the method of evolutionary population synthesis, with careful consideration of the variation of the horizontal-branch morphology with metallicity and age. We find (a) that while metal lines are little af-fected, the $H{\beta}$ index is severely enhanced (up to 30%)by the presence of the blue horizontal-branch stars, frustrating the current age-estimations from this index with out careful consideration of these stars, and (b) that there is a systematic trend in the sense that the globular clusters in giant elliptical galaxies appear to be older than those in our Galaxy by several billion years. We also calculate these indices for the stellar populations with a metallicity spread, by adopting metallicity distribution functions predicted by chemical evolution models. The comparison of the models with the observed indices of the central regions of the early-type galaxies yields the results (a) that the ages of the giant elliptical galaxies would be older than the previous estimations by several billion years, and (b) that there is a considerable age spread among elliptical galaxies, in the sense that the giant elliptical galaxies are older than small ones.

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영.유아의 연령과 성별에 따른 식행동과 식품 기호도에 관한 연구 (Study of Eating Behavior and Food Preference in Young Children: Differences by Age and Gender)

  • 서소정;민인자;신한승
    • 동아시아식생활학회지
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    • 제19권5호
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    • pp.659-667
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    • 2009
  • The primary object of this study was to examine both preferences in a variety of foods and snacks and the eating habits among young children (aged 13 months through 50 months old). In addition, this study examined whether there would be significant differences in the preferences and eating habits by of young children of different ages and gender of young children. This study included 193 infants (85 boys, 108 girls) of aged 13 through 50 months of old who were enrolled in early childhood education and care settings in Seoul and Gyunggi Province. The information regarding food and snack preferences among young children were gathered through surveys filled out by their mothers and the children's overall eating habits were assessed by their teachers. The main results of this study were as follows. Overall, there were some patterns in eating bere asss and food preferences in foods and snacks among young children. There were no significant differences in both eating bere asss and food preferences by gender of young children. But, however, there were significant differences in food (p<0.001) and snack preferences (p<0.001) by of children of different ages of young children.

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Seasonal Growth and Root Respiration of North American Ginseng

  • John, T.A. Proctor;Dean, Louttit;Jirong, Jiao
    • Journal of Ginseng Research
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    • 제22권3호
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    • pp.161-167
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    • 1998
  • American ginseng plants (Panax quinquefolium L.) of various ages were harvested every two weeks during each of three growing seasons and dry matter yield of components and root respiration determined. Shoot dry weight was about 0.5 g, 2.5 g and 4 g for 2, 3 and 4-year-old plants, respectively and fruit dry weight was as much as 50% of this in 3- and 4-year-.old plants. Root dry weight decrease by 30~50% as shoots emerged and at the end of the season was about 2 g, 3.5 g and 5 g in 2, 3, 4 and 5-year-old plants, respectively. Shoot and root dry weight were linearly related with an approximate 1:2 ratio. Root respiration rate at 2$0^{\circ}C$ in the dark was about 5 $\mu\textrm{g}$ CO2 g-1 DW(dry weight) min-1 in the early season, then doubled within 50 days as shoots emerged, and thereafter declined over the season to 2~5 $\mu\textrm{g}$ CO2 g-1 DW min-1. The Q10 for dark respiration over the interval from 10 to 2$0^{\circ}C$ was 1.58. Root respiration rate and shoot growth rate was positively linearly related in all ages of plants. Key words: Dry weight, partitioning.

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재생 굵은 골재를 사용한 재생 콘크리트의 역학적 특성에 관한 실험적 연구 (An Experimental Study on the Mechanical Properties of Concrete with the Contents of Recycled coarse Aggregate)

  • 김호수;백철우;반성수;최성우;류득현
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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    • pp.25-30
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    • 2003
  • Owing to the deterioration of reconstruction and the construction, much of the construction waste is discharged in our construction field. By supplementing aggregate resources that are insufficient by recycling waste concrete, it is considered that the resource-preserving effect according to the saving and reuse of resource as well as eco-friendly effect that is regarded as important in recent industrial society may be expected. In this study conducted an experiment by setting up 15 levels according to the variations in the rate of substitution of recycled coarse aggregate by the water cement ratio(40, 50, 60%). As the result of it, the slump and air contents was increased by ratio of coarse aggregate, and the elapsed characteristics by the ratio of recycled coarse aggregate showed that there is no clear difference in slump and the air contents. Further, in the characteristics of strength development, the lower the water cement ratio, the higher the compressive strength at early ages, compared with crushed stone, while the compression declined according to the increase of substitution rate of recycled gravel as it was tending upward long-term ages.

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수중불분리성콘크리트의 고품질화 연구 (A Study on high Quality of Antiwashout Underwater Concrete)

  • 문한영;김성수;전중규;송용규
    • 콘크리트학회논문집
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    • 제12권5호
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    • pp.111-120
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    • 2000
  • In case of constructing concrete structure under water, generally concrete mixed with antiwashout admixture, high range water reducer, or AE-water reducing agent etc has been manufactured to ensure the quality of antiwashout underwater concrete because of being difficulty in ascertaining construction situation by the naked eye. The properties of high quality antiwashout underwater concrete that were aimed at affluent fluidity, workability and the compressive strength of 450 kgf/$\textrm{cm}^2$ at 28 ages using two types of blended cements are following as;(1) Setting time of antiwashout underwater concretes using blended cements was more greatly delayed than that of control concrete, however, was satisfied with criteria value of "Quality standard specification of antiwashout admixture for concrete".(2) As a test results of slump flow, efflux time and box elevation of head, it was found that workability of high quality antiwashout underwater concrete was improved. (3) Heat evolution amount of OPC was 1.5 times as high as that of two types of bended cements in 72 hours. (4) Suspended solids of antiwashout underwater concrete using blended cements was more than that of control concrete, also compressive strength of high quality antiwashout underwater concrete was very low in early age, but was better than that of control concrete as to increasing ages.

Differential Expression of Multiple Connexins in Rat Corpus and Cauda Epididymis at Various Postnatal Stages

  • Lee, Ki-Ho
    • Journal of Animal Science and Technology
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    • 제55권6호
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    • pp.521-530
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    • 2013
  • Direct cell-cell communication via the transfer of small molecules between neighboring cells in tissue is accomplished by gap junctions composed of various connexins (Cxs). Proper postnatal development of the epididymis is important for acquisition of male reproduction. The epididymal epithelium is composed of several cell types, and some of these cells are connected by gap junctions. The present study was conducted to determine the presence of Cx transcripts in the corpus and cauda epididymis. In addition, transcriptional changes of Cxs expressed during different postnatal stages were examined by real-time PCR analysis. In both epididymal regions, the same nine Cx transcripts of thirteen Cxs tested were detected. In the corpus epididymis, the highest levels of Cxs31.1 and 37 transcripts were observed at 45 days of age, and amounts of Cxs26, 30.3, and 32 transcripts increased with age and subsequently decreased in the elderly. Expression of Cx31 was greatly increased in the adult and elder stages, while Cxs40, 43, and 45 were abundant in the early postnatal stages. In the cauda epididymis, expression of Cxs26, 30.3, 31.1, 37, and 40 reached the highest levels at 5 months of age. The levels of Cxs31 and 32 mRNAs fluctuated throughout the postnatal period. The amounts of Cxs43 and 45 transcripts were more abundant during the late neonatal and prepubertal ages than later ages. These findings suggest that regional specification of the epididymis is partly regulated by differential expression of Cx genes during the postnatal developmental period.

노년 초기 재혼자의 결혼성립 과정과 결혼만족에 관한 연군 (The Marital Process of Completion and Marital Satisfaction of Remarried People at Early Old Age)

  • 최영아
    • 대한가정학회지
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    • 제43권5호
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    • pp.15-42
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    • 2005
  • The Purpose of this study was to explore the relation between the marital process of completion and marital satisfaction. The Data was collected by in_depth personal interview. Fifteen respondents who had been remarried for over 5 years were chosen by a researcher independently from a province in South Korea and comprised 8 females(over 55 ages) and 7 males(over 60 ages ). The Results were as fellows: 1. The Remarriage process of completion was an important process for arranging a marriage with a partner. This process was reached through the remarriage motive of the remarried person who was chosen by introduction of a family member or a friend and through meeting with a familiar friend. The factors were remarriage motive, meeting with a spouse, children's response about remarriage, and remarriage decision. 2. The success of the marital process of completion depended on a support from families and friends in order to develop their conjugal relation. Therefore conjugal relation was an important relation in marital satisfaction. Particularly, the parents-child relation, relation between a stepbrother and stepsister, and social support for remarried persons were important relations in their marital satisfaction.