• Title/Summary/Keyword: natural light

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Physical Properties of Lightweight and Normal Weight Concretes due to Water-Cement Ratio Changes (물-시멘트비 변화에 따른 경량콘크리트와 일반콘크리트의 물리적 성질)

  • Lee, Chang-Soo;Kim, Jae-Nam;Lim, Youn;Ma, Moon-Hak
    • Journal of the Korean Society of Hazard Mitigation
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    • v.9 no.4
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    • pp.11-20
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    • 2009
  • By using the artificial lightweight aggregate for the natural aggregate depletes and destruction of environment and the application of lightweight concrete in structure, the lightweight concrete is manufactured. The fundamental characteristics by the waterbinder ratio was evaluated. It is suggested the method to control of pre-absorbed water of the lightweight aggregate. Lightweight concrete with pre-absorbed aggregate has similar characteristics compared to normal weight concrete regardless of water-binder ratio. According to the water-binder ratio, the drying condition, and the rebar, the unit mass of the lightweight concrete showed the reduction of 14.6${\sim}$21.0% as the range of 1,668${\sim}$1,998 $kg/m^3$ in comparison to the normal weight concrete. The lightweight aggregate pre-absorbed water showed the deferent evaporation quantity according to the water-binder ratio. As the water-binder ratio is lower, the oven dry vapour water is larger, therefore the internal curing water is increasing. In the same water-binder, comparing the normal concrete the lightweight concrete shows lower compressive strength which is due to the different strength of an aggregate. In the air dry curing, the normal weight concrete has a lower strength improvement effect in w/c 0.3 than the ratio 0.4 and 0.5. However, the strength improvement effect has increasing as the water-binder ratio was low in the light concrete.

Taxonomical and Ecological Study on the Vegetation of the Seungbong Island (승봉도 식물상에 관한 분류 및 생태학적 연구)

  • Lee, Ho Joon;Seon Choel Choi;Young Hee Lee
    • Journal of environmental and Sanitary engineering
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    • v.5 no.2
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    • pp.105-116
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    • 1990
  • Seungbong Island is situated about 100km away Inchon Port in the western sea of the Korean Peninsula. Field investigations were conducted for two days each from June 30 through July 1, 1981 and from August 20 through 21, 1981. The results obtained are summarized as follows: Plants growing in this island consist of a total of 193 species (70 families, 151 genera, 170 species, 22 varieties and 1 forma). Pinus thunbergii was confirmed to be the dominant species. The natural degree observed in this island was high, as a whole. The coefficient of ferny plants (Pte-Q) is 0.95, lower than grass. Atractylodes japonica Koidz., Miscanthus sinensis Anders. var. purpurascense Rendle, and Rhododendron mucronulatum Turz. are distributed mainly on the forest bed of Pinus thunbergii. The poor distribution of Chenopodium album var. centrorubrum Makino, Setaria viridis (L.) Beauv., Amaranthus mangostanus Linne is considered attributable to the phenomenon of allellopathy caused by a chemical substance secreted from the leaves of Pinus thunbergii. The component ratio of species in this island is lower than that of other islands due probably to the small area of arable land and grassland. The poor growth of plants in the forest of Pinus thunbergii, the dominant species in this island, seems to be attributed to the low relative light intensity of the forest. Seaside plants consisting of a total of 7 species were distributed mainly in the vicinity of sandy beaches. Naturalized plants comprising a total of 11 species were relatively diversified in the number of species.

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Community dynamics of Salix species during the sedimentation in Paksil-nup Wetland, Hapcheon (합천 박실늪의 퇴적에 따른 버들류 (Salix sp.)의 군집 동태)

  • Kim, Cheol-Soo;Lee, Pal-Hong;Son, Sung-Gon;Oh, Kyung-Hwan
    • Journal of Wetlands Research
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    • v.2 no.1
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    • pp.19-29
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    • 2000
  • The physico-chemical characteristics of core sediment, community dynamics of Salix species during the sedimentation were investigated in 1990~1997 for the purpose of inquiry to reveal the effects of terrestrialization on the environment and plant community in a natural wetland. The study site, Paksil-nup wetland was a valley blocked lake located near Hwang-River, Hapcheon-gun, Gyeongsangnam-do, Korea. The values of conductivity, organic matter, total nitrogen, exchangeable K, and exchangeable Ca were higher, and pH was lower in the upper layer of the core sediment. Soil properties such as available phosphorus, exchangeable Ca, exchangeable Na increased, and organic matter, total nitrogen, exchangeable K decreased during the sedimentation. Salix nipponica was the dominant species, and Salix glandulosa was subdominant among 10 Salix species. Sahx species were supposed to be the pioneer plants in shrub and tree layers during the succession in Paksil-nup wetland. Age class of SaliX species community from the epilittoral zone to the infralittoral zone were low, and age of Saljx species distributed from 2 years to 11 years. DBH, height, mean number of branches, number of herb species, and light intensity were increased, whereas density was decreased from a lower age to a higher age community. Salix nipponica was superior than Sahx purpurea var. japonica and other Salix species during the interspecific competition among Salix species.

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Increase of Salt and Low Temperature Tolerance by Overexpressing Glutathione S-Transferase (GST) Gene (염분과 저온에 대한 내성증진을 위한 GST 유전자의 과발현)

  • Jun Chol Kim;Il Seop Kim;Won Hee Kang
    • Journal of Bio-Environment Control
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    • v.11 no.3
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    • pp.139-143
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    • 2002
  • Cotton Glutathione S-Transferase (GST: EC 2.5.1.18) was cloned and overexpressed in tobacco (Nicotiana tabacum) plants. Northern blot analysis confirmed the successful transformation of cotton gst gene in tobacco plant. Type I and Type ll transcript patterns were identified in transgenic tobacco plants and only Type I transcripts were discussed in this paper, The activity of GST in the type II transgenic plants was about 1.5-fold higher than those of the wild type and non-expresser by using 1-chloro-2,4-dinitrobenzene (CDNB) and reduced glutathione as the substrate. The expression of cotton GST in tobacco plants proved that Gh-5 could be translated into functional protein. Type II transgenic plants produced functional GST in the cells. The effects of cotton GST in the seedlings was evaluated by growing the control and transgenic seedlings at $15^{\circ}C$ in the growth chamber in the light. Overexpressors were grown well compared to the control plants (non-expressors). lo test far tolerance to salinity, seeds of Gh-5 overexpressors and the wild type Xanthi seedlings were grown at 0, 50, 100, 150, and 200 mM NaCl solution. Gh-5 transgenic seedlings showed higher growth rate over control seedlings on 50 and 100 mM NaCl solution. There was no difference in growth rate at 150 and 200mM NaCl concentration.

The Analysis of Instantaneous $CO_2$ Uptake and Evapotranspiration of Herbaceous Plants for Artificial Roof Greening (옥상녹화용 초본식물의 순간 $CO_2$ 흡수 및 증발산량 분석)

  • Ahn, Geun-Young;Han, Seung-Won;Lee, Eun-Heui
    • Korean Journal of Environment and Ecology
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    • v.25 no.1
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    • pp.91-101
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    • 2011
  • The purpose of this study is to demonstrate the positive effects of artificial ground greening on the reduction of carbon dioxide ($CO_2$) which can help improve ecological functions in cities and mitigation of climate change, through quantifying $CO_2$ uptake and evapotranspiration by the process of photosynthesis of some plants. Experiment of $CO_2$ uptake and evapotranspiration was conducted by measurement of $CO_2$ exchange rate using the infrared gas analyzer, for 7 month, growing season from May to November 2009, 2 times a month. The result was as follows; The $CO_2$ uptake quantity per $cm^2$ of Chrysanthemum zawadskii was the highest rate at $21.47{\times}10^{-6}g/cm^2/s$ and Poa pratensis was $16.20g{\times}10^{-6}g/cm^2/s$. The stronger was light of intensity, the higher were $CO_2$ uptake rate of most plants. In quantity of evapotranspiration, Poa pratensis was the highest rate at $8.75{\times}10^{-5}g/cm^2/s$ and Aquilegia buergariana was $8.66{\times}10^{-5}g/cm^2/s$. From this study, it is confirmed that artificial ground greening has capacity of absorption $CO_2$ and effects on improving urban microclimate.

The Study on living Art and Costumes Culture of the Middle-Age Europe (중세유럽의 생활미술과 복식문화에 관한 연구)

  • 이순홍
    • Journal of the Korean Society of Costume
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    • v.35
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    • pp.17-44
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    • 1997
  • Medieval European practical art and style of costume is studied through referring to the literatures. The type of clothing that was seen on tapestries arts and crafts paintings and wall paintings and appeared in the architecture such as church. There were symbolic aspects of color motifs at this period and some restraints for clothing according to the social class, It was a period that draped garments due to the War of Crusades is appeared. Be-cause the medieval taste and decorative character is not only 'formative art' but also the taste beyoud 'mode' and atomsphere of that times it could be seen the strong reflec-tion of customs in the clothing of that times which is shown in works of art. 1) The purpose of Christian art which was found in mosaics stained glasses wall pain-tings and statues of architecture was not just the revival of natural phenomena but visuali-zation of sacred and invisible things. It was valuable to understandin of the spiritual through the sense organ It was a monumental art that was combined with decorative func-tion and role of the Bible. It revealed what was about the religious spiritual miracle, 2) In the medieval European painting characteristic and beautiful creativity was the basis of an argument. Both "Worship of East-ern" that is painted ion a parchment and "Cor-onation of Charles VI" were described decor-ation motifs on the edge of buildings geo-metric patterns and others with outstanding skill. there were precise technologic skill of architect and glassmen and lots of patience of craftsmen. " The Labour of the Months" and the scene of"A Trial at the Court" is also de-scribed elaborately. 3) Tapestry was developed in France Ger-many Swiss at the 14th century. Religionary and historical themes unicorn lady bird flowering plants and others were major motifs. It was very important as decorative wall coverings and as practical door arch and bed hangings. It was made through patient hard work with simple technique and it was con-sidered as an art for practical use. Tapestry was what everyone wish to have. It is reckoned for the item of the best gift. The royalty and nobility ordered and used custom-made tapestries. Sometimes the subject of motifs consisted of series which were deeply related to living 4) Decorative arts and crafts was the art that used materials such as precious metals jewels and others and that accorded with the luxurious and gorgeous taste of the royalty and nobility. Christian considered splendid and beautiful color of light as a symbol of glory. They used also for church appliances, There were metal crafts wood crafts textile crafts and others, As was stated above the costume appeared on the arts and crafts for living revealed the process of changes saw how the politic econ-omic and social organizations were developed.and social organizations were developed.

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Preliminary Research on the Implementation of Information of Human Facial Part Required for the 3D Printing of Eye Shield (안구차폐체 제작에 필요한 안면부 3차원 정보 구현의 기초연구)

  • Choi, Seokyoon
    • Journal of the Korean Society of Radiology
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    • v.13 no.7
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    • pp.955-960
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    • 2019
  • The Computed tomography (CT) scan can have high radiation in a few tests, and this risk is significant given that it is often repeated in one patient. In children, the incidence of radiation-induced cancer is reported because organs are growing, are more sensitive to radiation. 3D printing has recently been studied to be applied to various applications as a research field for 3D printing applications, research on fabrication of radiation shields and materials has been conducted. The purpose of the 3D printer is to replace the existing panel-type shields and to make customized designs according to the shape of the human body. Therefore, research on 3D information processing to be input to the 3D printer is also necessary. In this study, 3D data of the human body surface, which is the preliminary step of the manufacture of patient-specific eye shield using stereo vision depth map technology, was studied. This study aims to increase the possibility of three-dimensional output. As a result of experimenting with this method, which is relatively simple compared with other methods of 3D information processing, the minimum coordinates for 3D information are extracted. The results of this study provided the advantages and limitations of stereo images using natural light and will be the basic data for the manufacture of eye shields in the future.

Research on the Decolorization of Epoxy Polymer by Accelerated Solar Radiation Test (태양광 복사 가속화 시험을 통한 에폭시 폴리머의 색 변화 특성 연구)

  • Lee, Sang-Bong;Lee, Dong-Geon;Kim, Myung-Jun;Lee, Soo-Yong;Park, Jung-Sun;Kang, Tae-Yeop;Baek, Sang-Hwa
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.44 no.11
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    • pp.949-956
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    • 2016
  • There are a number of effects by solar radiation in many aerospace industrial fields, such as degradation of mechanical properties, sealing effect of sealants or decolorization. Because it takes long time to investigate these effects by using the light of natural state, new methods are developed for accelerating this phenomenon. In this paper, we developed an apparatus to simulate accelerated solar radiation phenomenon selecting irradiation intensity $1,120W/m^2$ as the designed environment. Epoxy polymer as the composite material was chosen and processed by ASTM-D638, a reference for tensile test of polymer and plastic. Total color shift was selected as the test category to evaluate acceleration of the test. We obtained acceleration factors and numerical model from test data and concluded it can shorten test periods by accelerated irradiation intensity of $1,120W/m^2$.

Moth (Lepidoptera) Fauna of Golf Courses in Jinju, Gyeongsangnamdo, Korea (경남 진주지역 골프장의 나방상 연구)

  • Kim, Jong-Ju;Lee, Suk-Jun;Jung, Young-Hak;Lee, Sang-Myeong;Choo, Ho-Yul;Lee, Dong-Woon
    • Asian Journal of Turfgrass Science
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    • v.25 no.1
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    • pp.30-42
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    • 2011
  • Moths were collected to survey turfgrass pest and to compare species diversity from Jinju Country Club in Jinju, Gyeongsangnamdo, Korea, every 10 days using 200W mercury light trap from middle May to late October in 2008. As the results, only 23 individuals of Pseudaletia separata, Spodoptera depravata, Spodoptera litura, Agrotis segetum, and Agrotis ipsilon were collected as turf grass insect pests. However, 2028 individuals of 388 species in 22 families were collected in total. Dominant species was Culcula panterinaria, Fentonia ocypete, Hypsopygia regina, Culcula panterinaria, Flavocrambus striatellus, and Diarsia camescens in May, June, July, August, September and October, respectively. Species diversity was not different between two surveyed sites, but different among surveyed time. Species richness was more higher in hole 11 (Hole was surrounded by natural forest and located near pond) than hole 15 (Hole was located at the top part of mountain). Dominance index of moth was increased from October compared with diverse index and richness index were decreased from October. A large number of species and individuals were recorded in Noctuidae (502 individuals in 131 species), Geometridae (491 individuals in 84 species), Pyralidae (386 individuals in 73 species), and Notodontidae (277 individuals in 25 species). These four families were 80.9% out of all the collected species.

Palynological and Revisional Studies of Thalictrum L. in Korea (한국산 꿩의다리속(Thalictrum L.) 식물의 화분학적 연구와 분류학적 재검토)

  • Jeon, Kyoungsuk;Heo, Kyeongin;Lee, Sangtae
    • Korean Journal of Plant Taxonomy
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    • v.37 no.4
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    • pp.447-476
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    • 2007
  • The pollen and revisional study aimed for an elucidation of taxonomic delimitation and relationship of Thalictrum taxa in Korea, especially among the morphologically confused taxa. Pollen grains of 63 populations of 17 taxa were investigated by light and scanning electron microscopy. Although pollen morphology was not useful for the species classification, it revealed a tendency in which Sects. Physocarpum, Erythrandra and Tripterium having broad filaments and round-tipped anthers possess closer distance between adjacent pores, less echinus number per unit area, smaller pollen, and higher echinus, on the contrary to Sects. Omalophysa, Camptonotum and Thalictrum having filiform filaments and acute-acuminate- or more or less round-tipped anthers. The palynological result did not support several section system by Tamura (1992) but one section system by Lecoyer (1885). If a infrasectional system is needed, it was suggested that the system dividing the section into two (Clauiformes and Filiformes sensu Lecoyer) would be natural on the basis of stamen and pollen characteristics. Revisional study found out that 17 taxa(16 species) of Thalictrum are distributed in Korean including T. filimentosum which presence in Korea was not confirmed.