• Title/Summary/Keyword: 한국 제4기학회

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Zoeal Stages of Aipheus euphrosyne richardsoni Yaldwyne, 1971 (Decapoda: Macrura: Alpheidae) Reared in the Laboratory (Aipheus euphrosyne (새우아목, 딱총새우과)의 Zoea 유생)

  • 양회정;김창현
    • The Korean Journal of Zoology
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    • v.39 no.1
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    • pp.106-114
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    • 1996
  • Zoeae of Alpheus euplirosyne rlchardsoni Valdwyne, 1971 reared in the laboratory are described and Illustrated The culture was carded out under the laboratory condition with the photoperiod l4hr light and lOhr darkness and salinity of 33.3$\textperthousand$ at 25$^{\circ}$C. This species exhibits extended development on the egg size just before hatching and on the length of the first zoea. The morphological differences between the first zoea of this species and those of five other species in the same genus are discussed.

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Radio-Carbon Age Determination by Tandem Accelerator Mass Spectrometry Technique and Its Application To The Korean Sea (탄뎀가속기에 의한 방사성탄소 년대측정과 한국해에의 적용)

  • Suk, Bong-Chool;Toshio Nakamura;Nobuyuki Nakai;Asahiko Taira
    • The Korean Journal of Quaternary Research
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    • v.4 no.1
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    • pp.27-40
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    • 1990
  • $^{14}C$ age dating by AMS (accelerator mass spectrometry) technique was performed on twenty five small sized fossil shells and one peat taken from the sixteen piston cores in the southern and southeastern Korean Sea. AMS technique is available to date only a few milligram of amorphous carbons compare than conventional dating technique. It is described in detail of sample pre-treatment and experimental, and applied to the reconstruction of the sea level changes since the late Pleistocene in the Korean Sea. Dated age ranges from 520$\pm$100 to older than 33,500 years. Sedimentary facies in the study area represents a different environmental set which is affected by sea level fluctuation since the late Pleistocene.

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Design of a CDBC Using Multirate Sampling (Multirate 샘플링을 이용한 CDBC의 설계)

  • 김진용;김성열;이금원
    • Journal of the Institute of Convergence Signal Processing
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    • v.4 no.4
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    • pp.47-51
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    • 2003
  • Due to the asymptotic property, deadbeat control which is well used in digital control system can not be applied to the continuous time system. But recently by use of the finite Laplace Transform to transfer function and establishment of some settling conditions, CDBC(Continuous time Deadbeat Control) is studied. For CDBC design, transfer function is constituted with delay elements and then order and interpolation conditions are derived. In other way, digital deadbeat controller is implemented and it's output is changed to continuous type by smoothing elements. In this paper multirate sampling is used and so inner controller is sampled faster than output feedback loop. And End order smoothing elements is placed to the output of digital deadbeat controller. By the multirate sampling overall output response is improved. The controller is impleneted as a serial integral compensator in the forward path and a local feedback compensator introduced into the outpute feedback loop. Matlab Simulink is used for simulation.

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Recent Progress in Mussel-inspired Catechol-conjugated Chitosan Hemostats (홍합 모사 카테콜기가 도입된 키토산 지혈제 연구 동향)

  • Seongyeon Jo;Soomi Kim;Chanwoo Park;Seungwon Hong;Hong Kee Kim;Ji Hyun Ryu
    • Journal of Adhesion and Interface
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    • v.24 no.4
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    • pp.113-119
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    • 2023
  • Since it was reported that the unusual amino acid DOPA in synergy with lysine and histidine residues found in mussel adhesive proteins plays a pivotal role in mussel adhesion in underwater environments, there has been a burgeoning development of various catecholamines-based adhesives for biomedical applications. Among these, catechol-conjugated chitosan, containing catecholamine, featuring multiple catechol groups within its aminerich chitosan backbone, has found versatile utility in fields, such as tissue adhesion, wound dressing, tissue healing, hemostats, drug delivery systems, and tissue engineering scaffolds. Significantly, chitosan-catechol is a mussel-inspired material approved by both US Food and Drug Administration (FDA) and KR Ministry of Food and Drug Safety (MFDS) for its effectiveness in hemostasis. This review focuses on 1) general aspects of catechol-conjugated chitosan, highlighting catechol group integration into chitosan backbones, 2) examination of proposed mechanisms of hemostasis, and 3) exploration of diverse physical forms, including solution, hydrogels, patches, and thin films with practical applications inapplicable to hemostasis.

Design of Hydrogen Peroxide Turbopump and Water Test (과산화수소 터보펌프 설계 및 수류시험)

  • Lee, Sung-Gu;Park, Dae-Jong;Kwon, Se-Jin
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2011.11a
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    • pp.317-320
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    • 2011
  • Hydrogen peroxide turbopump was designed for bi-propellant liquid rocket engine using hydrogen peroxide and kerosene as propellants. Turbopump operation was verified through water tests. Design conditions of hydrogen peroxide turbopump were determined, and impeller was designed. Turbine which drives pump was selected from commercial turbocharger. Gas generator was designed by reference from turbine map. Pump, turbine, gas generator were integrated, and turbopump system was constructed. Turbopump supplied water by 1.47 bar of pressure and as well as 3.4 kg/s of mass flow rate.

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Development of High Pressure Sub-scale Regeneratively Cooled Combustion Chambers (고압 축소형 재생냉각형 연소기 개발)

  • Kim, Jong-Gyu;Lee, Kwang-Jin;Seo, Seong-Hyeon;Han, Yeoung-Min;Choi, Hwan-Seok
    • Journal of the Korean Society of Propulsion Engineers
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    • v.13 no.6
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    • pp.8-16
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    • 2009
  • The development of high-pressure sub-scale combustion chambers is described. A total of four high-pressure sub-scale combustion chambers having either a detachable structure of the mixing head and the chamber or a single welded regenerative cooling structure have been developed. The sub-scale combustion chambers have a chamber pressure of 70 bar and propellant mass flow rate of 5.1~9.1 kg/s. The propellant mass flow rate and the recess number of the injector were changed for the improvement of combustion performance and they were validated through hot firing tests. The design and manufacturing techniques of regenerative cooling channel and film cooling to be applied to the full-scale combustion chamber were adopted through the present development and verified.

Development of Metal Compound Explosives Using KIO4 and TiH2 (KIO4와 TiH2를 이용한 금속복합화약 개발)

  • Ahn, Gilhwan;Kim, Sangbaek;Kim, Junhyung;Ryu, Byungtae
    • Journal of the Korean Society of Propulsion Engineers
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    • v.24 no.1
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    • pp.58-63
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    • 2020
  • THPP is a type of metallic complex explosive used in initiators, consisting of TiH2 and KClO4. In this case KClO4 includes ClO4- which is a harmful substance that may cause thyroid dysfunction or tumors. In this study KIO4 is applied to a new type of environmentally friendly explosive as a substitute to the conventional KClO4. Tests were carried out to see if KIO4 can be made a successful replacement for KClO4.

Past and Future Temperature and Precipitation Changes over Korea using MM5 Model

  • Oh, Jai-Ho;Min, Young-Mi;Kim, Tae-Kook;Woo, Su-Min;Kwon, Won-Tae;Baek, Hee-Jeong
    • Proceedings of the Korean Quaternary Association Conference
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    • 2004.06a
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    • pp.29-29
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    • 2004
  • Long term observational analysis by climatologists has confirmedthat the global warming is no longer a topic of debate among scientists andpolicy makers. According to the report of IPCC-2001 (Intergovernmental Panelon Climate Change), the global mean surface air temperature is increasinggradually. The reported increase of mean temperature is by 0.6 degree in the end of twentieth century. This could represent severe threat for propertylosses especially due to increase in the number of extreme weather arising out of global warming. period of model integration from 2001 to 2100 using output of ECHAM4/HOPE-G of Max Planet Institute of Meteorology (MPI) for IPCC SRES (Special Report on Emission Scenarios). The main results of this study indicate increase of surface air temperature by 6.20C and precipitation by 2.6% over Korea in the end of 21st century. Simulation results also show that there is increase in daily maximum and minimum temperatures while decrease in diurnal temperature range (DTR). DTR changes are diminished mainly due to relatively rapid increase of daily minimum temperature than that of daily maximumtemperature. It has been observed that increase in precipitation amount anddecrease in the number of rainy days lead to increase of pre precipitationintensity.

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