• Title/Summary/Keyword: Slush

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Heat Transfer Characteristics During Slush Formation in the Evaporator of a Small Slush Maker (소형 슬러시 제조기 증발기에서 슬러시 형성시 전열 특성)

  • Choi, Yong-Min;Kim, Do-Young;Kim, Nae-Hyun;Lee, Eul-Jong;Kim, Soo-Hwan;Byun, Ho-Won
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.21 no.11
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    • pp.643-648
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    • 2009
  • Tests were conducted to obtain heat transfer coefficients during slush formation from 10% sucrose solution. The slush was made by scraping the ice formed on the cylinder. Cold brine was supplied inside of the evaporator cylinder to cool the outer surface. Below a certain brine temperature, which was $-5^{\circ}C$ in this study, the solution was supercooled, and suddenly turned into ice crystals. During slush formation, the heat transfer coefficient oscillated significantly, due to periodic removal of ice chunk form the surface. The average heat transfer coefficient during slush formation was 40~70% higher than that obtained during single phase cooling. The heat transfer coefficient was also affected by the brine temperature with increasing heat transfer coefficient at higher brine temperature.

An Economic Analysis on Slush Hydrogen Containing Liquid and Solid Phase for Long-Term and Large-Scale Storage (장주기/대용량 수소저장을 위한 액체/고체기반 Slush 수소의 저장 비용 분석)

  • PARK, SUNGHO;LEE, CHANGHYEONG;RYU, JUYEOL;HWANG, SEONGHYEON
    • Transactions of the Korean hydrogen and new energy society
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    • v.33 no.3
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    • pp.247-254
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    • 2022
  • Slush hydrogen containing liquid and solid hydrogen is expected to achieve zero boil-off by suppressing boil-off gas because heat of fusion for solid absorbe the heat ingress from atmosphere. In this paper, quantitative analysis on storage cost considering specific energy consumption between 1,000 m3 class liquid hydrogen storage system with re-liquefaction and slush hydrogen storage system during equivalent zero boil off period. Even though approximately 50% of total storage capacity should be converted into solid phase during the initial cargo bunkering, total energy consumption to convert into slush hydrogen is relatively 25% less than re-liquefaction energy for boil off hydrogen during zero boil off period. That's because energy consumption of slush phase change take up only 1.8% of liquefaction energy. moreover, annual revenue requirement including CAPEX, OPEX and electric cost for slush hydrogen storage could be more reduced approximately 32.5% than those of liquid hydrogen storage and specific energy storage cost ($/kg-H2) could also be lowered by about 41.7% compared with liquid hydrogen storage.

Heat Transfer Characteristics of Small Slush Maker (소형 슬러시 제조기의 전열현상에 관한 연구)

  • Kim, Do-Young;Kim, Nae-Hyun;Oh, Wang-Kyu;Choi, Yong-Min;Byun, Ho-Won
    • Proceedings of the SAREK Conference
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    • 2008.06a
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    • pp.346-350
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    • 2008
  • Tests were conducted to obtain heat transfer coefficients during slush formation from 10% sucrose solution. The slush was made by scraping the ice formed on the cylinder. Cold brine was supplied inside of the cylinder to cool the outer surface. Below a certain brine temperature, which was $5^{\circ}C$ in this study, the solution was supercooled, and suddenly turned into ice. The super-cooling increases as the brine temperature increased. During slush formation, the heat transfer coefficient oscillated significantly, due to periodic removal of ice chunk form the surface. The average heat transfer coefficient during slush formation was approximately twice of that obtained during single phase cooling. The heat transfer coefficient was also affected by the brine temperature with increasing heat transfer coefficient at lower brine temperature.

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Technical Review on Liquid/Solid (Slush) Hydrogen Production Unit for Long-Term and Bulk storage (장주기/대용량 저장을 위한 액체/고체(Slush) 수소 생산 장치의 해외기술 동향분석)

  • LEE, CHANGHYEONG;RYU, JUYEOL;SOHN, GEUN;PARK, SUNGHO
    • Transactions of the Korean hydrogen and new energy society
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    • v.32 no.6
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    • pp.565-572
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    • 2021
  • Hydrogen is currently produced from natural gas reforming or industrial process of by-product over than 90%. Additionally, there are green hydrogens based on renewable energy generation, but the import of green hydrogen from other countries is being considered due to the output variability depending on the weather and climate. Due to low density of hydrogen, it is difficult to storage and import hydrogen of large capacity. For improving low density issue of hydrogen, the gaseous hydrogen is liquefied and stored in cryogenic tank. Density of hydrogen increase from 0.081 kg/m3 to 71 kg/m3 when gaseous hydrogen transfer to liquid hydrogen. Density of liquid hydrogen is higher about 800 times than gaseous. However, since density and boiling point of liquid hydrogen is too lower than liquefied natural gas approximately 1/6 and 90 K, to store liquid hydrogen for long-term is very difficult too. To overcome this weakness, this paper introduces storage method of hydrogen based on liquid/solid (slush) and facilities for producing slush hydrogen to improve low density issue of hydrogen. Slush hydrogen is higher density and heat capacity than liquid hydrogen, can be expected to improve these issues.

A study on the practical measures of the corporate crime investigation -Focusing on white color crime-

  • Nam, SeonMo
    • International Journal of Advanced Culture Technology
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    • v.8 no.2
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    • pp.96-100
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    • 2020
  • In this paper, I try to help the business operation so that they could continue the desirable operation despite the unfavorable conditions. It is important to reinforce for corporate growth various support measures to generate profits. However, if they are involved in criminal activities such as slush fund creation, they will have to deal with them separately. As a result, To raise awareness helps to keep the company running. Recently, the companies are in a poor condition due to overseas migration. If a company does not create profits by doing business, it is a burden to continue operating and it will eventually be hard to support and destroy. The corporate crime and white-collar crime are mostly similar types, mainly because they occur in the industry. The corporate crime proceeds throughout the company and ultimately translates into corporate profits. The white-collar crime, on the other hand, is a profitable part of the individual. In the process of generating profits, the purpose and management method of slush funds is an important issue in judging whether illegal immorality of business is intended or not. In addition, in the case of the corporate crime, it seems necessary to identify the types of slush fund raising activities in addition to the investigations of the accomplices and clinical investigations, and to apply efficient investigation methods on a case-by-case basis. At present, many companies frequently migrate overseas due to the influence of domestic regulations. In this process, if it is involved in crime such as a borrowing accounts or the purpose of slush fund creation should be treated separately.

A Clinical Review of Phrenic Nerve Paralysis associated with the Use of Iced Slush for Topical Hypothermia during Cardiac Surgery (개심술후 합병되는 횡격신경마비에 관한 임상적 고찰)

  • 이재성
    • Journal of Chest Surgery
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    • v.20 no.3
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    • pp.483-488
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    • 1987
  • Phrenic nerve injury has been reported with the use of iced slush for topical cardiac hypothermia. A review of the preoperative and the postoperative chest roentgenograms was performed to detect phrenic nerve injury in patients undergoing cardiac operation with the use of iced slush for topical hypothermia from January, 1985 to June, 1987. The reviewed series included 45 patients who had undergone valve replacement. In this review, the injured site of phrenic nerve was left in 13 cases, right in 1 case and the overall incidence of phrenic nerve paralysis following open heart surgery was 31%. Compared to the incidence of phrenic nerve paralysis in the control group [without pericardial insulation] [406, 12 cases/30 cases], that in the group of patients receiving pericardial insulation [13.3%, 2 cases/15 cases] was lower, but there was no statistical significance. The initial time that diaphragmatic paralysis developed was mean 3.5 days [range 1-8 days] postoperatively and the recovery time of the paralysis was mean 4.7 months [range 0.5-10.5 months] postoperatively.

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Surface Area and Micropore Volume Measurements of Spherocarb and Sucrose Char (Spherocarb와 Sucrose Char에 대한 비표면적과 세공부피의 측정)

  • Kim, Hak-Hee;Park, Sang-Jin
    • Applied Chemistry for Engineering
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    • v.5 no.1
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    • pp.105-113
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    • 1994
  • The amount of nitrogen gas adsorbed by Spherocarb and Sucrose Char was measured as a function of the relative pressure with temperature being kept constant at 77 to 184K. Isotherms at different temperatures were obtained by keeping the adsorbent at a constant temperature using liquid nitrogen, iso-pentane, n-pentane, ethyl alcohol, and iso-propyl alcohol slush baths. The objective for this study is to provide information on the specific surface area and pore volume by analyzing the experimental data using adsorption models such as the Brunauer-Emmett-Teller and Dubinin-Radushkevich models.

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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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