• Title/Summary/Keyword: Ice pressure

검색결과 180건 처리시간 0.026초

수분무에 의한 아이스 슬러리 생성에 관한 연구 (A study on ice-slurry production by water spray)

  • 김병선;이윤표;윤성영;이진호
    • 설비공학논문집
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    • 제9권2호
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    • pp.134-143
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    • 1997
  • A theoretical and experimental study has been performed to investigate the characteristics of ice-slurry product. By diffusion-controlled model, the possibility of ice slurry has been theoretically anticipated. The water vapor evaporated from the surface of droplets is extracted continuously from the chamber by a vacuum pump. The droplet diameter was measured by silion immersed method. The ice slurry has been obtained by spraying droplets of ethylene-glycol aqueous solution in the chamber where pressure is maintained under the triple point of water. The droplet of which the diameter is $300{\mu}m$, and the initial temperature is $20^{\circ}C$, was changed into ice particle within the chamber of which the height is 1.33m.

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A Study on Ice Slurry Production by Water Spray

  • Kim, Byeong-Sun;Lee, Yoon-Pyo;Yoon, Seong-Young;Lee, Jin-Ho
    • International Journal of Air-Conditioning and Refrigeration
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    • 제6권
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    • pp.45-55
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    • 1998
  • A theoretical and experimental study is performed to investigate the characteristics of ice slurry product. By diffusion-controlled evaporation model the possibility of ice slurry is theoretically anticipated. The water vapor evaporated from the surface of droplets is extracted continuously from the chamber by a vacuum pump. The droplet diameter is measured by silicon immersion method. The ice slurry is obtained by spraying droplets of ethylene glycol aqueous solution in the chamber where pressure is maintained under the triple point of water. The droplet with the diameter of 300 $\mu\textrm{m}$and the initial temperature of 2$0^{\circ}C$ was changed into ice particle within the chamber of 1.33m in height.

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심장수술 환아의 흉관제거시 통증에 대한 냉요법의 효과 (Effects of Ice pack application for the postcardiac surgery toddlers before C-tube removal)

  • 신희선;김동옥;조경미
    • 대한간호학회지
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    • 제25권2호
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    • pp.341-350
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    • 1995
  • A quasi-experimental study was conducted to examine the effect of ice pack application to post cardiac surgery toddlers before C-tube removal. Twenty toddlers aged 13 months to 24 months, who were admitted to the hospital for open heart surgery during the period from July, 1993 to October, 1993 were randomly assigned to the experimental or control group. An ice pack was applied to the C-tube insertion site for 8 minutes before C-tube removal for the experimental group. The children were videotaped during the procedure to assess pain behavior and crying time. The score on the Modified Behavioral Pain Scale(MBPS), crying time, and vital signs were measured to determine the effect of ice pack application. The data were analyzed using Mann-Whitney U test, Paired t-test, and Pearson correlation coefficient. The result of the study are as follows : 1. There was a significant difference between the experimental group and the control group in pain behavior (U=17.0, p=.01). 2. There was no significant difference between the two groups in crying time. 3. There was a significant difference between the two groups in heart rate (U=24.5, p=.05). 4. There was a significant difference between the two groups in systolic blood pressure (U=24.0, p=.05) 5. There was a significant difference between the two groups in diastolic blood pressure (U=23.0, p=.04). 6. There was no significant difference between the two groups in respiration rate. 7. Pain behavior was significantly correlated with heart rate, systolic blood pressure, and crying time (r=.50, .54 and .59, p<.05). The result showed that the ice pack application was effective to reduce pain related to C-tube removal for the toddlers. From the study, it is recommended that the effectiveness of the cold ap-plication to children undergoing different painful procedures be examined to determine the most effective length of cold application to reduce pain in children.

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Effects of Pressure-shift Freezing on the Structural and Physical Properties of Gelatin Hydrogel Matrices

  • Kim, Byeongsoo;Gil, Hyung Bae;Min, Sang-Gi;Lee, Si-Kyung;Choi, Mi-Jung
    • 한국축산식품학회지
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    • 제34권1호
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    • pp.33-39
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    • 2014
  • This study investigates the effects of the gelatin concentration (10-40%, w/v), freezing temperatures (from $-20^{\circ}C$ to $-50^{\circ}C$) and freezing methods on the structural and physical properties of gelatin matrices. To freeze gelatin, the pressure-shift freezing (PSF) is being applied at 0.1 (under atmospheric control), 50 and 100 MPa, respectively. The freezing point of gelatin solutions decrease with increasing gelatin concentrations, from $-0.2^{\circ}C$ (10% gelatin) to $-6.7^{\circ}C$ (40% gelatin), while the extent of supercooling did not show any specific trends. The rheological properties of the gelatin indicate that both the storage (G') and loss (G") moduli were steady in the strain amplitude range of 0.1-10%. To characterize gelatin matrices formed by the various freezing methods, the ice crystal sizes which were being determined by the scanning electron microscopy (SEM) are affected by the gelatin concentrations. The ice crystal sizes are affected by gelatin concentrations and freezing temperature, while the size distributions of ice crystals depend on the freezing methods. Smaller ice crystals are being formed with PSF rather than under the atmospheric control where the freezing temperature is above $-40^{\circ}C$. Thus, the results of this study indicate that the PSF processing at a very low freezing temperature ($-50^{\circ}C$) offers a potential advantage over commercial atmospheric freezing points for the formation of small ice crystals.

수중 하베스트형 빙축열 시스템의 운전특성 실험 (Experiments on Operation Characteristics of In-Water Harvest-Type Ice Storage System)

  • 최인수;김재돌;윤정인
    • 대한기계학회논문집B
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    • 제25권5호
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    • pp.653-659
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    • 2001
  • This paper is concerned with the development of a new method for making and separating ice in-water and saving floated ice by installing an evaporation panel in an ice storage tank. The new method shows very good heat transfer efficiency than that of the convectional method. It is because the evaporation panel is directly contacted with water in the storage tank. The experiments were performed by varying inlet and outlet refrigerant temperatures of its evaporator. From the experimental results, the operating characteristics of in-water harvest-type ice storage system were investigated by measuring temperature and pressure at each point of the ice storage system and power required to operating compressor respect to the changes of the inlet and outlet refrigerant temperature of evaporator. It can be think that defrost frequency decreased and heavy ice created as the refrigerant temperature of evaporator outlet and defrost setting temperature is low so gotten result can effect to release efficiency. Also, consumption power, condensing heat quantity, refrigerating capacity and performance efficiency decreased as time goes by. Therefore, these results provide the basic data for system optimization, performance improvement and the possibility of application to other fields.

아이스 콘 금형의 유동해석 (Flow analysis of Ice Cone Die)

  • 이종선;김세환
    • 한국산학기술학회:학술대회논문집
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    • 한국산학기술학회 2002년도 추계학술발표논문집
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    • pp.253-257
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    • 2002
  • 본 논문에서는 아이스크림용 아이스 콘에서 콘 부분을 만들기 위한 금형의 제작시 필요한 구조적 안정성을 평가할 수 있는 유동해석을 수행하였다. 유동해석을 수행하기 위하여 상용 유한요소해석 코드인 ANSYS클 활용하였으며 내압조건, 경계조건, 구속조건 등을 고려하여 아이스 콘 금형내부의 유동 흐름을 압력조건의 변화에 따라 구하였다.

드라이아이스 펠렛 분사에 의한 모의 시편의 제염 (Decontamination of Simulated Test Piece by Dry Ice Pellet Blasting)

  • 신진명;박장진;양명승
    • 환경위생공학
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    • 제19권2호
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    • pp.30-36
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    • 2004
  • Dry decontamination technique is required for maintaining nuclear material handling equipment contaminated with highly radioactive material in a hot cell. In order to determine the optimum blasting conditions of dry ice pellet blasting device, the basic experiments have been conducted on the simulated test specimens of four types of metals. The removal efficiency of test piece was evaluated by the XRF analysis and the change of the surface condition before and after blasting. The removal efficiency of cesium on loose contamination was 100% under blasting pressure; 3 kg/$cm^2$, blasting distance; 10 cm, blasting time: 10 sec. In case of fixed contamination, the removal efficiency of cesium was almost 96% under blasting pressure; 4kg/$cm^2$, blasting distance; 10 cm, blasting time; 30 sec.

TGV & ICE Series의 전두부 디자인 형상변천에 관한 연구 (A study on the Changes of TGV & ICE Series' Nose Shape)

  • 이희엽;홍석기;나희승
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2007년도 추계학술대회 논문집
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    • pp.1835-1842
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    • 2007
  • The purpose of this paper describes the changes of TGV & ICE series' nose shape by increasing train speed and according to the periodical characteristics. As the speed increases, the length of the nose shape trends to lengthen longer. But the nose shape length does not increase as speed improves by optimized nose shape to reduce aerodynamic drag and micro-pressure wave in tunnels. TGV & ICE series' nose shape can be classified into Advanced paraboloid type, Shape-nosed type, Organic double-edged type and Flat-nosed type by the advance research(the changes of Shinkansen vehicle' nose shape) of high speed railway. Because it trends to be diversified and characterized more and more. This paper analyzed and introduced as TGV & ICE series' nose shape by top 2 nation (Germany, France) and high speed railway in the past years(1980-2007) for their railway design trends by new positioning(Advance research).

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판형 열교환기를 이용한 과냉각수용액에서 유동과냉도 및 냉각속도가 연속제빙에 미치는 영향 (Influence of the Supercooling Degree and Cooling Rate on a Continuous Ice Formation by a Supercooled Aqueous Solution in Flow Using a Plate Heat Exchanger)

  • 이동규;백종현;홍희기;강채동
    • 설비공학논문집
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    • 제19권9호
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    • pp.647-653
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    • 2007
  • In dynamic ice storage system(DISS), ice slurry is formed not only from solution freezing by mechanical removing parts but also supercooled solution. However, in order to perform continuous ice formation in the system without mechanical moving parts, supercooled aqueous solution should be formed stable through cooling heat exchanger and be dissolved uniformly in storage tank. In previous study, the time of ice slurry increased as the pressure of the cooling heat exchanger(PHX) increased. In this study, a cooling experiment of an ethylene glycol 7mass% solution was performed with various inlet temperature of the PHX, which has constant brine inlet temperature of $-7^{\circ}C$. The temperature in the storage tank maintained to freezing point of the solution. At results, the time of ice slurry formation increased as the supercooling degree decreased and the cooling rate increased.

조명 정보를 이용한 얼음의 투명도 측정 (Luminance based transparency measurement for ice)

  • 배정호;박민찬;이재근;차의영
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2009년도 춘계학술대회
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    • pp.419-421
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    • 2009
  • 얼음의 경우 주변의 압력, 습도 등의 환경에 따라서 결빙점이 달라지는데 얼음의 투명도를 측정함으로써 얼음의 결빙 과정을 유추할 수 있고 얼음의 밀도 등의 특징을 파악하는데 도움이 된다. 본 논문은 이미지 상에 포함되어 있는 얼음의 투명도를 측정하는 방법을 제시하고자 한다. 얼음이 포함된 이미지를 먼저 $CIEL^*a^*b^*$ 색 공간으로 변경한 후, $L^*$ 값의 평균과 RMS(Root Mean Square) Contrast를 조합해서 얼음의 투명도를 측정하는 지수를 만들었다. 얼음 이미지의 경우 Wever Contrast나 Michelson Contrast 등 기존의 컨트라스트 비교에 비해 훨씬 만족할만한 성능을 보여주었다.

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