• 제목/요약/키워드: Decay time

검색결과 894건 처리시간 0.028초

Ch'ing Dragon Robes (청조의 용포소고)

  • 박춘순;김재임
    • Journal of the Korean Society of Costume
    • /
    • 제50권3호
    • /
    • pp.59-72
    • /
    • 2000
  • Dragon robe was defined as a robe on which the principal design consisted of dragon. Dragon patterns have been used on princess robes during T'and Dynasty. In Sung, Dragon-figured robes seem to have an Imperial prerogative. Yuan took over the use of robes with dragons patterns as a definite institition. Ming tried to reject all Yuan innovations, the dragon robe was retained as an unofficial court costume. The Emperor's semiformal robes which at first had four dragon medallions, later had twelve along with the 12 Symbols(십이장문). As Ch'ing dragon robes were only intended fro semiformal use. The Later Ch'ing robes date from after 1719, when the Ch'ien-lung(건륭) introduced 12 Symbols on Ch'ing robes. The Ch'ien-lung laws were disobeyed, notably the ones that specified the number of claws on the dragons. THe Emperor's dragon robe, lung-p'ao, (용포) was described as bright yellow in color, having four slits and horsefoof cuffs. The basic pattern consisted of nin dragons, in addition it had 12 Symbols. The elaborate textile techniques reached their peak in Ch'ing Dynasty-with its Weaving and Dyeing Office in Peking, and this factories at Hangchow(항주), Soochow(소주), and Naking(남경) -helps to explain why the decay of the Ch'ing bureaucracy hastended the decline of dragon robes. In the Ch'ing Dynasty tow terms were used for dragon robe, depending on the number of claws on the dragons. Those with five-clawed dragons were called lung-p'ao, while those with four-clawed dragons were called mang-p'ao(망포). The Court felt compelled to take corrective meausres. It decreeed that Ninisters of State and other officials, who had been bestowed five-clawed lung dragons, must take out one claw. Finally, the sale of ranks and the attendant privilege of wearing dragon robes gradually increased during the 18 th century, reaching its height in the 19 th century, Finally, after the Taiping Rebellion, when the Imperial Treasury was depleted by the wholesale destruction of revenue-producing lands, the Chinese government came to depend on such sales as an important source of revenue and the practice became even more widespread. The ensuing mass production of dragon robes, and the necessity of conforming to the fairly rigid basic pattern established in 1759, resulted in marked deterioration of workmanship, and a comparative monotony of decoration. The patterns on the dragon robes slight changes continued to be made in the ways of representign them. The li shui (입수) portion at the base of the robe become inreasingly wider throughout the 19th century. The background became cluttered with symbols of good fortune, scattered among the clouds and waves. As a result of all this extraneous decoration, the dragons were so crowded that they had to shrink back into the small size that they had originally occupied in the medallons. Kuang-hsu(광저) was a long one, allowing time for the manufacture of numerous robes. Also, it would seem likely that Occidental museums and collections would have a considerable number of his robes, in view of the widespread looting of his palaces during the Allied occupation of Peking in 1900, and the frequent sales of Late Ch'ing imperial textiles by destitute Manchu courtiers in the '20's.

  • PDF

Synthesis of Zn2SiO4 : Mn Phosphor Particles by Spray-pyrolysis Method (분무 열 분해법을 이용한 Zn2SiO4 : Mn 나노 형광체의 광학적 특성에 관한 연구)

  • Nam, Sang-Hun;Kim, Myoung-Hwa;Lee, Sang-Duck;Boo, Jin-Hyo
    • Journal of the Korean Vacuum Society
    • /
    • 제19권1호
    • /
    • pp.66-71
    • /
    • 2010
  • Spherical shape $Zn_2SiO_4:Mn$ phosphor particles with the mean particle size from submicron to micron sizes were prepared by ultrasonic spray pyrolysis method. A droplet separator was introduced to control the size distribution of the phosphor particles with spherical shape. The $Zn_2SiO_4:Mn$ phosphor particles with 2 mol% doping concentration of manganese have decay time and have photoluminescence intensities comparable with those of the latest commercial product prepared by the solid state reaction method. The size of the phosphor particles was decreased from 1 to 0.2 micrometers as the inorganic salt solution concentration was changed from 0 to 5 M. The phosphor particles prepared from the solutions above 0.5 M have photoluminescence intensities comparable with that of the latest commercial product.

Photoluminescent Properties of $\textrm{Zn}_{2}\textrm{SiO}_{4}$: Mn Green Phosphors doped with Ga (Ga 도핑된 $\textrm{Zn}_{2}\textrm{SiO}_{4}$: Mn 녹색 형광체의 발광특성)

  • Park, Eung-Seok;Jang, Ho-Jeong;Jo, Tae-Hwan
    • Korean Journal of Materials Research
    • /
    • 제8권9호
    • /
    • pp.860-864
    • /
    • 1998
  • We investigated the photoluminescence and the crystalline properties with Ga doping concentrations (0-12 mol%) in $\textrm{Zn}_{1.98}\textrm{Mn}_{0.02}\textrm{SiO}_{4}$ green phosphors prepared by the solid state reaction. The photoluminescence was improved by a doping of Ga element in $\textrm{Zn}_{1.98}\textrm{Mn}_{0.02}(\textrm{Si_{1-x}\textrm{Ga}_{x})\textrm{O}_{4}$ phosphors which showed the highest emission intensity and good color purity in the doping concentration of x=0.08. The emission intensity of $\textrm{Zn}_{1.98}\textrm{Mn}_{0.02}(\textrm{Si_{1-x}\textrm{Ga}_{x})\textrm{O}_{4}$(x= 0.08) phosphors was increased to 7 times with increasing the sintering temperatures from $1100^{\circ}C$ to $1400^{\circ}C$, showing the improved crystalline quality. The decay time was not affected by Ga doping concentrations with constant values around 24ms. It was found from SEM and PSA analyses that the phosphors were composed of a large number of small grains around 1-3$10\mu\textrm{m}$ with a small amounts of agglomerated particles above $10\mu\textrm{m}$.

  • PDF

Synthesis of O-(3-[18F]Fluoropropyl)-L-tyrosine (L-[18F]FPT) and Its Biological Evaluation in 9L Tumor Bearing Rat

  • Moon, Byung-Seok;Kim, Sang-Wook;Lee, Tae-Sup;Ahn, Soon-Hyuk;Lee, Kyo-Chul;An, Gwang-Il;Yang, Seung-Dae;Chi, Dae-Yoon;Choi, Chang-Woon;Lim, Sang-Moo;Chun, Kwon-Soo
    • Bulletin of the Korean Chemical Society
    • /
    • 제26권1호
    • /
    • pp.91-96
    • /
    • 2005
  • O-(3-[$^{18}$F]Fluoropropyl)-L-tyrosine (L-[$^{18}$F]FPT) was synthesized by nucleophilic radiofluorination followed by acidic hydrolysis of protective groups and evaluated with 9 L tumor bearing rat. L-[$^{18}$F]FPT is an homologue of O-(2-[$^{18}$F]fluoroethyl)-L-tyrosine (L-[$^{18}$F]FET) which recently is studied as a tracer for tumor imaging using positron emission tomography (PET). [$^{18}$F]FPT was directly prepared from the precursor of O-(3-ptoluenesulfonyloxypropyl)- N-(tert-butoxycarbonyl)-L-tyrosine methyl ester. FPT-PET image was obtained at 60 min in 9 L tumor bearing rats. The radiochemical yield of [$^{18}$F]FPT was 0-45% (decay corrected) and the radiochemical purity was more than 95% after HPLC purification. The total time elapsed for the synthesis of [$^{18}$F]FPT was 100 min from EOB (End-of-bombardment). A comparison of uptake studies between [$^{18}$F]FPT and [$^{18}$F]FET was performed. In biodistribution, [$^{18}$F]FPT showed similar pattern with [$^{18}$F]FET in various tissues, but [$^{18}$F]FPT showed low uptake in brain. Furthermore, [$^{18}$F]FPT showed higher tumor-to-brain ratio than [$^{18}$F]FET. In conclusion, [$^{18}$F]FPT seems to be more useful amino acid tracer than [$^{18}$F]FET for brain tumors imaging with PET.

A Study on the Structural Behavior of an Underground Radwaste Repository within a Granitic Rock Mass with a Fault Passing through the Cavern Roof (화장암반내 단층지역에 위치한 지하 방사성폐기물 처분장 구조거동연구)

  • 김진웅;강철형;배대석
    • Tunnel and Underground Space
    • /
    • 제11권3호
    • /
    • pp.257-269
    • /
    • 2001
  • Numerical simulation is performed to understand the structural behavior of an underground radwaste repository, assumed to be located at the depth of 500 m, in a granitic rock mats, in which a fault intersects the roof of the repository cavern. Two dimensional universal distinct element code, UDEC is used in the analysis. The numerical model includes a granitic rock mass, a canister with PWR spent fuels surrounded by the compacted bentonite inside the deposition hole, and the mixed bentonite backfilled in the rest of the space within the repository cavern. The structural behavior of three different cases, each case with a fault of an angle of $33^{\circ},\;45^{\circ},\;and\;58^{\circ}$ passing through the cavern roof-wall intersection, has been compared. And then fro the case with the $45^{\circ}$ fault, the hydro-mechanical, thermo-mechanical, and thermo-hydro-mechanical interaction behavior have been studied. The effect of the time-dependent decaying heat, from the radioactive materials in PWR spent fuels, on the repository and its surroundings has been studied. The groundwater table is assumed to be located 10m below the ground surface, and a steady state flow algorithm is used.

  • PDF

Analysis of the Disposal Tunnel and Disposal Pit Spacing for the Spent Fuel Repository Layout (사용후핵연료 지하 처분장 배치를 위한 처분공 및 처분터널 간격 분석)

  • Lee, Jong-Youl;Lee, Yang;Choi, Heui-Joo;Choi, Jong-Won
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
    • /
    • 제4권4호
    • /
    • pp.393-400
    • /
    • 2006
  • In design of a deep geological repository for the high level wastes, it is very important that the temperature of the bentonite block should not be over $100^{\circ}C$ to maintain the integrity of the bentonite buffer block from the decay heat. In this study, for the layout of the repository to meet the requirement, the analysis of the disposal tunnel and disposal pit spacing was carried out. To do this, based on the reference repository concept, several cases of cooling times and disposal tunnel and disposal pit spacing were compared. The thermal stabilities of the disposal systems were analyzed in terms of the cooling time and spacing. The results showed that it was more desirable to determine the layout of the repository in terms of disposal pit spacing than the disposal tunnel spacing. The results of these analyses can be used in the deep geological repository design. The detailed analyses with the exact site characteristics data will reduce the uncertainty of the results.

  • PDF

Growth and Scintillation Characteristics of CsI(Br) Single Crystals (CsI(Br) 단결정의 육성과 섬광특성)

  • Oh, M.Y.;Jung, Y.J.;Lee, W.G.;Doh, S.H.;Kang, K.J.;Kim, D.S.;Kim, W.;Kang, H.D.
    • Journal of Sensor Science and Technology
    • /
    • 제9권5호
    • /
    • pp.341-349
    • /
    • 2000
  • CsI(Br) single crystals doped with 1, 3, 5 or 10 mole% $Br^-$ ions, as an activator, were grown by Czochralski method. The lattice structure of grown CsI(Br) single crystal was bcc and its lattice constant was $4.568\;{\AA}$. The absorption edge of the CsI(Br) single crystals was observed at 243 nm. The spectral range of the luminescence excited by 243 nm of wavelength was $300{\sim}600\;nm$, and its peak emission appeared at 440 nm. The luminescence intensity was maximum when CsI(Br) was doped with 3 mole % $Br^-$ ions. The energy resolutions of the CsI(Br) scintillator doped with 3 mole % $Br^-$ ions were 15.0% for $^{137}Cs$(662 keV), 13.1% for $^{54}Mn$(835 keV), and 18.0% and 6.3% for $^{22}Na$(511 keV and 1275 keV), respectively. The decay curves had fast and slow components, and the fast component was about 41 ns independent on the concentration of the $Br^-$ ions. The time resolution of CsI(Br) scintillators decreased with increasing of the concentration of $Br^-$ ions.

  • PDF

Current Research Status of Postharvest and Packaging Technology of Oriental Melon (Cucumis melo var. makuwa) in Korea (국내 참외의 수확 후 관리 및 포장기술 연구)

  • Kim, Jung-Soo;Choi, Hong-Ryul;Chung, Dae-Sung;Lee, Youn-Suk
    • Horticultural Science & Technology
    • /
    • 제28권5호
    • /
    • pp.902-911
    • /
    • 2010
  • Oriental melon ($Cucumis$ $melo$ var. $makuwa$) is a popular and high-value market fruit cultivated in Korea. Consumers are becoming increasingly interested in oriental melon as a healthy diet over the past few years. However, the melons have relatively high quality loss because the fruit are mainly produced for a limited period of time in the summer season. Lack of the proper postharvest treatments and high temperature exposure at harvest or during distribution are the most critical environmental factors limiting postharvest life of fruit. This review focuses on the overview of current research studies for postharvest treatment and functional packaging technology of oriental melon in Korea. Major physiological problems of the harvest fruit include the ripening process in quality changes of the produce such as loss of weight, firmness, flavor, and decay during the storage periods. Low temperature at 7 to $10^{\circ}C$ with high relative humidity of 90 to 95% is the suitable environmental condition used to maintain the quality of fresh oriental melon. Controlled atmosphere (CA) storage or modified atmosphere (MA) packaging can be used as supplemental treatments to extend postharvest-life. For oriental melon, an optimum CA is currently recommended to be 2-3% oxygen and 5-10% carbon dioxide atmosphere. Precooling, pretreatments of ethylene action and functional packaging system can be applied to oriental melon after harvest in order to extend storage life. Major active packaging technologies are concerned with a selectively gas permeable film related to respiration of produce and the packaging applications of ethylene removal, antimicrobial, and antifogging substances to keep the effective freshness of fruit.

A Study on Development Directions of System for the Level Diagnosis of U-City for U-City Activation (U-City 고도화를 위한 수준진단체계 개발방향에 관한 연구)

  • Jang, Hwan Young;Lim, Yong Min;Lee, Jae Yong
    • Journal of Korean Society for Geospatial Information Science
    • /
    • 제23권2호
    • /
    • pp.49-58
    • /
    • 2015
  • Up to the present point in time, the level diagnosis system for urban reactivation have utilized various methods for establishment and management in Korea and overseas, such as city competitiveness evaluation, urban decay diagnosis, etc. However, contrary to performing diagnosis and evaluations on general cities in existing studies, it is found to be a very complex and difficult task to perform a diagnosis on the level of U-City due to its unique characteristics. It is difficult to determine the level of a U-City using a level diagnosis system used for general cities because a U-City is comprised of a connection/fusion of various structural elements. Therefore, in order to perform a systematic diagnosis of a U-City, it is necessary to primarily observe the structural characteristics of a U-city to derive a diagnosis system based on the relativity between each structural element. This study aims to propose a directivity of a U-City level diagnosis system in comprehensive consideration of various elements, such as the objective of a U-City, as well as the structural elements that compose a U-City based on the definitions prescribed in U-City legislations, including ubiquitous city planning, ubiquitous city infrastructure, ubiquitous city technology, services, etc. The results of this study are expected to provide a resolution for the regional quality differences of U-Cities, and also establish a stepping-stone for the realization of U-Cities with high degree of completion.

Screening of Eu3+-and Tb3+-Activated Phosphors for PDP in the System of CaO-Gd2O3-Al2O3 (CaO-Gd2O3-Al2O3계에서의 PDP용 Eu3+와 Tb3+ 활성 형광체의 탐색)

  • Park, Sang-Mi;Kim, Chang-Hae;Park, Hui-Dong;Jang, Ho-Gyeom;Park, Jun-Taek
    • Journal of the Korean Chemical Society
    • /
    • 제46권4호
    • /
    • pp.336-345
    • /
    • 2002
  • In this study, we have screened $Eu^{3+}$- and $Tb^{3+}$-activated candidate phosphors for PDP in the sys-tems of CaO-Gd$_2$O$_3$-Al$_2$O$_3$ by combinatorial chemistry and investigated the synthetic temperature, optimum com-position and luminescent properties about the candidate phosphors. To construct the emission intensity library by VUV PL, we have synthesized 210 different compositional samples using a polymerized-complex method. Good luminescent samples were identified by X-ray diffraction method. $Ca_$\alpha$$G$d_{0.95-$\alpha$-$\beta$}Al_$\beta$O_$\delta$$ : Eu(0.02< $\alpha$+$\beta$ <0.04) phos-phors screened as a red phosphor have good color purity than commercial phosphor. In the candidate phosphors of CaGdAl$_3O_7$ : Tb, Ca$Al_{12}O_{19}$ : Tb, Gd$_4$Al$_2O_9$ : Tb, and Gd$_3Al_5O_{12}$ : Tb CaGdAl$_3O_7$ : Tb, and Ca$Al_{12}O_{19}$ : Tb have shorter decay time than commercial phosphor.