• Title/Summary/Keyword: ice-2

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An Application of Plasticity Model for Ice Deformation Characteristics (수변형 특성에 있어서 소성 모델의 응용)

  • Choe, Gyeong-Sik
    • Journal of Ocean Engineering and Technology
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    • v.4 no.2
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    • pp.15-21
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    • 1990
  • This study focuses the mechanical deformation response predicted by the plasticity model for polycrystalline ice. To describe various deformation characteristics, ice is idealized as a perfectly plastic material using an asymptotic exponential failure criterion. This criterion is suite for describing materials which exhibit brittle deformation at low hydrostatic pressure and ductile deformation at high hydrostatic pressure. The results are compared to those of continuum damage mechanics model. Plasticity model shows good agreement with damage model and experimental results for high confining pressures even at high strain-rates which is usually considered as a brittle condition under uniaxial compression.

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An Application of Plasticity Model for Ice Deformation Characteristics (수변형 특성에 있어서 소성 모델의 응용)

  • Choe, Gyeong-Sik
    • Journal of Ocean Engineering and Technology
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    • v.4 no.2
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    • pp.165-165
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    • 1990
  • This study focuses the mechanical deformation response predicted by the plasticity model for polycrystalline ice. To describe various deformation characteristics, ice is idealized as a perfectly plastic material using an asymptotic exponential failure criterion. This criterion is suite for describing materials which exhibit brittle deformation at low hydrostatic pressure and ductile deformation at high hydrostatic pressure. The results are compared to those of continuum damage mechanics model. Plasticity model shows good agreement with damage model and experimental results for high confining pressures even at high strain-rates which is usually considered as a brittle condition under uniaxial compression.

Effect of Topical Hypothermia on Myocardial Protection from Ischemia - Experimental study using isolated rat heart perfusion technique- (흰쥐의 적출된 작업성 심장에서 허혈성 심정지시 국소냉각법이 심근보호에 미치는 영향)

  • 최종범
    • Journal of Chest Surgery
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    • v.21 no.2
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    • pp.231-239
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    • 1988
  • Currently numerous methods are in use for myocardial hypothermia as a myocardial preservation modality for cardiac operation. During cardiac ischemia after crystalloid cardioplegia[4C GIK solution], topical cold saline[Group I, a=9], topical ice slush[Group II, n=9] and topical ice chip[Group III, a=10] have been compared for myocardial surface cooling in the isolated rat heart model of cardiopulmonary bypass. During postischemic period, hemodynamic functions[aortic flow, coronary flow, peak aortic pressure and heart rate], biochemical enzymatic activities and cellular injuries with electron microscope were evaluated in this isolated rat heart perfusion model. Postischemic aortic flow, cardiac output and peak aortic pressure in Group I and Group II recovered better than Group III.[p< 0.05] Postischemic creatine kinase and lactate dehydrogenase leakages in Group II and Group III increased more than Group l and postischemic mitochondrial swelling in Group III was more severe than Group I, and Group II.[p< 0.05] These results suggest that topical cold saline was the better method than topical ice slush or topical ice chip as a myocardial preservation modality in the isolated rat heart model of cardiopulmonary bypass.

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Consumer′s Understanding and Preference for the Western Dessert in the Confectionery and Hotel (제과점 및 호텔에서 생산되는 서양 후식의 소비자 의식조사)

  • 정희선;주나미
    • Korean journal of food and cookery science
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    • v.18 no.2
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    • pp.262-273
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    • 2002
  • This study was conducted to investigate the general utilization and preference for the western desserts from confectioneries and hotels by the female university students in Seoul and Kyunggi area. The most high frequency of utilizing western desserts from confectioneries was 1∼3 times a month. Five items of confectionary dessert (chocolate, jelly, candy, cookie and ice cream) were preferred by house-dwellers and non-food science majors. And the families with higher income favoured chocolate and pie. The purchasing frequency of western desserts from confectionery was far more frequent in jelly and candy(1∼3 times a week) compared with chocolate, pies and cookies(1∼3 times a month) and sherbet and ice cream(1∼4 times a year). Hotel was used less frequently for purchasing western desserts. Cake was recognized well as a western dessert by the house-dwellers, and ice cream was recognized better by the apartment-dwellers (p<0.05). And the respondents with food science major had a wider preference for cake, pudding and ice cream(p<0.05).

An experimental study on heat transfer characteristics in the ice storage system of ice-on-coil type with rectangular finned tube during freezing process (직사각형 휜이 부착된 관외착빙형 빙축열조에서 응고과정시 열전달 특성에 관한 연구)

  • Kwon, H.Y.;Koh, J.Y.;Jeong, B.Y.;Yim, C.S.
    • Solar Energy
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    • v.20 no.4
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    • pp.61-67
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    • 2000
  • The purpose of this study is to improve heat transfer by attaching rectangular fins to tube. Experiments were carried out under the following conditions - Aspect ratio$(W_f/R_f)$ is 0.7, 1.2 and 1.8. Temperature conversion between high and low positions of water in the thermal storage appeared because maximum density point of water is about $4^{\circ}C$ and inlet direction of working fluid influenced conductive heat transfer Compared with the unfinned tube(bare tube), the rectangular tube increased the ice thermal storage energy and the ice thermal storage energy was increased as aspect ratio was increased.

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pH Characteristics of the Recycled Aggregate Being carbonated by Dry Ice (드라이아이스로 탄산화 처리한 순환골재의 pH 특성)

  • Hong, Sung-Rog;Bok, Young-Jae;Sung, Jong-Hyun;Lee, Il-Sun;Kim, Jin-Man
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2013.05a
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    • pp.337-338
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    • 2013
  • Recent research is needed for the reduction of the pH of the recycled aggregates, recycled aggregates for alkali social problems have emerged. This was confirmed through preliminary experiments using a self-made reactor with dry ice, the possibility of reducing the pH of the recycled aggregates. The pH reduction of coarse recycled aggregates plant was made to apply the field to the middle of construction waste treatment process to reduce the pH of the plant room, and measured the pH change with time. The measurement results showed that dry ice after the reaction, the pH of the aggregate 5% reduction than untreated recycled aggregates.

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PIV Measurement on Ice Slurry Pipe Flow (PIV에 의한 원관내 Ice Slurry의 유동계측)

  • Doh Deog Hee;Kim Dong Hyuk;Oh Cheol;Hong Seong Dae;Park Seong Ryong;Hwang Tae Gyu
    • Journal of Advanced Marine Engineering and Technology
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    • v.29 no.2
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    • pp.177-184
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    • 2005
  • Experimental studies on the characteristics of ice slurry flows in a circular pipe is rare due to the deficiency of conventional measurement techniques. In this report the flow characteristics are quantitatively investigated by the use of PIV technique concerning the Ice Packing Factor(IPF) and the power changes of pump motor It was experimentally verified that the power loss does not increase any more at a certain IPF value.

Modeling of the Formation of Long Grooves in the Seabed by Grounded Ice Keels

  • Marchenko, Aleksey
    • Journal of Ship and Ocean Technology
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    • v.7 no.4
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    • pp.1-15
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    • 2003
  • The motion of passively floating body, whose keel can have a contact with seabed soil, is under the consideration. The body simulates ice ridge floating in shallow water. The force of seabed soil reaction applied to the grounded keel is estimated taking into account soil embankment near the grounded keel. Two-dimensional trajectories of body motion, the shape of the grooves in seabed and the height of soil embankment are calculated when the motion of the body is caused by semidiurnal $M_2$ tide. The influence of wave amplitude and bottom slope on the shapes of body trajectory and the grooves are analyzed.

Infrared spectroscopy of the effect of metal electrode on adsorbate under electric field: Electrochemical model study of CO on Pt(111) with ice film capacitor method in ultrahigh vacuum

  • Kang, Hani;Shin, Sunghwan;Park, Youngwook;Kang, Heon
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.143.2-143.2
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    • 2016
  • The influence of electric field on CO adsorbed on Pt(111) was investigated with reflection-absorption infrared spectroscopy (RAIRS) in ultrahigh vacuum system. The ice film capacitor method was used to apply electric field to the amorphous ice film with CO on Pt(111). Two systems were compared by measuring the change of the CO stretching vibrational mode under applied electric field; one is CO on Pt(111), and the other is CO buried inside an ice film on Pt(111). By comparing them, we were able to calculate the additional effect of adsorption of CO on Pt(111) on peak shift. The CO adsorbed on Pt(111) has shown larger peak shift than CO adsorbed with H2O when we applied stronger electric field. Additionally, the differences were observable when the applied electric field exceeds $1{\times}10V/m^8$.

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Determination of dynamic threshold for sea-ice detection through relationship between 11 µm brightness temperature and 11-12 µm brightness temperature difference (11 µm 휘도온도와 11-12 µm 휘도온도차의 상관성 분석을 활용한 해빙탐지 동적임계치 결정)

  • Jin, Donghyun;Lee, Kyeong-Sang;Choi, Sungwon;Seo, Minji;Lee, Darae;Kwon, Chaeyoung;Kim, Honghee;Lee, Eunkyung;Han, Kyung-Soo
    • Korean Journal of Remote Sensing
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    • v.33 no.2
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    • pp.243-248
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    • 2017
  • Sea ice which is an important component of the global climate system is being actively detected by satellite because it have been distributed to polar and high-latitude region. and the sea ice detection method using satellite uses reflectance and temperature data. the sea ice detection method of Moderate-Resolution Imaging Spectroradiometer (MODIS), which is a technique utilizing Ice Surface Temperature (IST) have been utilized by many studies. In this study, we propose a simple and effective method of sea ice detection using the dynamic threshold technique with no IST calculation process. In order to specify the dynamic threshold, pixels with freezing point of MODIS IST of 273.0 K or less were extracted. For the extracted pixels, we analyzed the relationship between MODIS IST, MODIS $11{\mu}m$ channel brightness temperature($T_{11{\mu}m}$) and Brightness Temperature Difference ($BTD:T_{11{\mu}m}-T_{12{\mu}m}$). As a result of the analysis, the relationship between the three values showed a linear characteristic and the threshold value was designated by using this. In the case ofsea ice detection, if $T_{11{\mu}m}$ is below the specified threshold value, it is detected as sea ice on clear sky. And in order to estimate the performance of the proposed sea ice detection method, the accuracy was analyzed using MODIS Sea ice extent and then validation accuracy was higher than 99% in Producer Accuracy (PA).