• 한국식품과학회지
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• 제23권3호
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• pp.330-335
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• 1991

용질의 몰분율이 증가함에 따라 수분활성도의 저하효과가 큰 sorbitol, sodium lactate 및 sodium chloride를 보습제로 사용하여 water-sorbitol system에 미치는 sodium lactate 및 sodium chloride의 효과를 조사하였다. 수분과 sorbitol의 혼합무게비가 1 : 0.5322 및 1 : 0.7619인 water-sorbitol systems에서 첨가된 용질들과 sobitol 수용액내의 sobitol간에 상호작용이 일어났으며 이 상호작용된 양은 혼합무게비가 1 : 0.7619 경우보다 1 : 0.5322일 때 더 컸으며, 이때 첨가물로써 NaCl을 사용했을 때보다 sodium lactate를 사용했을 때 더 크게 나타났다. 이런 상호작용된 용질의 양의 변화는 0.87Aw 부근에서 가장 많았으며, 이 이하에서는 증가하는 경향을, 이 이상에서는 감소하는 경향을 나타냈다. 또한 중간수분식품의 수분활성도 범위인 0.70부터 0.90 사이에서 sodium lactate 및 NaCl를 각각 농도별로 첨가했을 때 이들 용질과 상호작용된 수분의 양이 가장 많게 나온 sorbitol 수용액은 수분과 sorbitol의 혼합무게비가 1 : 1.1241인 경우이었다. 또한 이때 첨가물로써 NaCl을 사용했을 때보다 sodium lactate를 사용했을 때 상호작용된 수분의 양은 더 많게 나타났다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.1829-1835
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• 2000

The experimental results of sodium-water reaction noise measurement in frequency range $1{/sim}200kHz$ are presented. The experiments of noise generation under the condition of sodium test facility, water leak rate $0.01{\sim}1.2g/s$ and temperature of sodium $250{\sim}500^{\circ}C$, were carried out. From theoretical study it is noted that the noise resonant attenuation on hydrogen bubbles in liquid sodium plays the significant role for leak noise spectra formation. Interaction of leak noise and hydrogen bubbles in sodium being accompanied by thermal, emission and viscosity energy dissipation was studied. Acoustic noise spectra were investigated from point of view of water leak detection in sodium/water steam generator. The results of sodium-water reaction noise absorption on hydrogen bubbles in liquid sodium by temperature $250{\sim}500^{\circ}C$ are presented. The theoretical model of noise absorption using the coefficients of attenuation was developed. From calculation the coefficients of attenuation were estimated.

• 약학회지
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• 제44권3호
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• pp.263-271
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• 2000

In an attempt to develop an injectable form of practically insoluble biphenyl dimethyl dicarboxylate (DDB), the effect of various vehicles, cosolvents and hydrotropic agents was investigated. It was found that polyethylene glycol (PEG) 400 revealed the best solvency toward DDB (17.7 mg/ml at $37^{\circ}C$), and decreasing order of the solubility was as follows: PEG 400>PEG 300>diethylene glycol monoethyl ether (DGME)>PEG-8 glyceryl caprylate/caprate. Among the hydrotropes used, sodium salicylate, sodium benzoate and nicotinamide were effective in increasing the solubility in water. The solubility of DDB in 2 M sodium salicylate, sodium benzoate and nicotinamide solutions was increased 44.3, 23.5 and 44.0 times than that in water, respectively. The addition of sodium salicylate and sodium benzoate to PEG 300-water PEG 400-water and DGME-water cosolvents remarkably increased the solubility of DDB, and significantly retarded precipitate formation when mixed with water Hemolytic properties of DDB injections (2 mg/4~10 ml) in PEG 300-water or DGME-water (60:40 v/v) cosolvents containing sodium benzoate (0.14~0.35 M) were very low. It was concluded from the results that these solutions would be applied to the design of new DDB injections.

• Korean Chemical Engineering Research
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• 제57권1호
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• pp.28-41
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• 2019

본 연구는 소듐냉각고속로 원형로 소듐-물 반응 압력완화계통의 성능 해석을 목적으로 한다. 증기발생기의 전열관 파단에 의한 대규모 물 누출 사고 발생 시, 증기발생기 전열관 내측의 물을 급수덤프탱크로 배출하고 전열관 외측의 소듐 및 반응생성물을 소듐덤프탱크로 배출 할 때 유체의 거동을 해석하여 계통 설계요건의 적절성을 평가하였다. 증기발생기 쉘 측의 액체와 중간열전달계통 내 소듐이 모두 배출되는데 소요되는 시간은 약 50초이고, 증기발생기 전열관 측의 급수가 모두 배출되는데 소요되는 시간은 약 2.5초로 계산되었다. 증기발생기와 중간열전달계통 내 유체가 덤프탱크로 배출되는 동안 전열관 측의 압력은 쉘 측의 압력보다 높게 유지되어 쉘 측의 소듐이 전열관 측으로 역류하는 현상은 없는 것으로 해석되었다. 본 연구의 결과는 SFR 원형로 소듐-물반응압력완화계통의 성능 평가에 대한 기초자료로 활용할 예정이다.

• Nuclear Engineering and Technology
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• 제56권3호
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• pp.893-899
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• 2024

In a secondary cooling system of a sodium-cooled fast reactor (SFR), rapid detection of hydrogen due to sodium-water reaction (SWR) caused by water leakage from a heat exchanger tube of a steam generator (SG) is important in terms of safety and property protection of the SFR. For hydrogen detection, the hydrogen detectors using atomic transmission phenomenon of hydrogen within Ni-membrane were used in Japanese proto-type SFR "Monju". However, during the plant operation, detection signals of water leakage were observed even in the situation without SWR concerning temperature up and down in the cooling system. For this reason, the study of a new hydrogen detector has been carried out to improve stability, accuracy and reliability. In this research, the authors focus on the difference in composition of hydrogen and the difference between the background hydrogen under normal plant operation and the one generated by SWR and theoretically estimate the hydrogen behavior in liquid sodium by using ultra-accelerated quantum chemical molecular dynamics (UA-QCMD). Based on the estimation, dissolved H or NaH, rather than molecular hydrogen (H₂), is the predominant form of the background hydrogen in liquid sodium in terms of energetical stability. On the other hand, it was found that hydrogen molecules produced by the sodium-water reaction can exist stably as a form of a fine bubble concerning some confinement mechanism such as a NaH layer on their surface. At the same time, we observed experimentally that the fine H₂ bubbles exist stably in the liquid sodium, longer than previously expected. This paper describes the comparison between the theoretical estimation and experimental results based on hydrogen form in sodium in the development of the new hydrogen detector in Japan.

• Food Science and Biotechnology
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• 제14권1호
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• pp.108-111
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• 2005

To improve water-resistance and physical properties of sodium alginate film, effects of sodium alginate and plasticizer concentrations, divalent cation types and concentrations, and immersion time of films into divalent cation solutions on sodium alginate films were evaluated, based on elongation strength (ES), elongation rate (E), water vapor permeability (WVP), and water solubility (WS). Film made from 1.5% sodium alginate solution (w/w) had low WVP and WS, which are optimal characteristics for application of film preparation. Addition of plasticizer increased E and WS. Less than 2% $CaCl_2$ addition and 15min immersion time reduced WVP, WS, and E significantly (p<0.05). Sodium alginate films treated with $CuCl_2$, and $ZnCl_2$ solutions had lower WVP and WS, whereas $MgCl_2$ had no influence on improving water resistance of films.

• 한국유체기계학회 논문집
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• 제20권2호
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• pp.69-74
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• 2017

Sodium hypochlorite, used as water disinfectant, is generated by electrolysis of salt. Compared to chlorine gas disinfection, it is free from high-pressure gas regulation and does not generate toxic gas, so it is increasingly used as a safe disinfectant. Despite these advantages, the concentration of sodium hypochlorite decreases with temperature during long-term storage, and the amount of chlorate increases when a large amount is added, it has mainly been applied to small-scale waterworks. To solve this problem, high sodium hypochlorite generation was developed. In this study, the changes of concentration and chlorate of sodium hypochlorite with time has been studied. As a result of the test, it was found that the usable period of sodium hypochlorite produced at a certain temperature or less was increased from 1.5 days to 13 days. Overall, sodium hypochlorite can be applied even in large-scale waterworks, which makes operation more stable and also reduces the disinfection byproducts, thus it contributed greatly to securing water quality.

• Childhood Kidney Diseases
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• 제14권2호
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• pp.111-119
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• 2010

1. 나트륨은 세포외액의 유효삼투압을 형성하는 가장 중요한 용질이며, 수분 밸런스의 이상은 혈중 삼투압의 변화와 혈중 나트륨농도의 이상(hyponatremia, hypernatremia)으로 발현된다. 2. 수분의 출입의 조절에 의하여 체액의 농도변화에 대처하는 과정을 수분 밸런스(water balance) 혹은 수분 대사(water metabolism)라 하며, 세포외 액량 특히 유효혈장량의 변화에 대처하여 체내 총 나트륨량의 출입을 조절하는 과정을 나트륨 밸런스($Na^+$ balance) 혹은 나트륨 대사($Na^+$ metabolism)라 하고 그 차이점을 정리하면 Table 1과 같다. 3. 수분 밸런스의 가장 중요한 두가지 요소는 갈증반응에 의한 수분섭취와 항이뇨호르몬(AVP)에 의한 소변으로의 수분 배출이며, AVP의 분비의 강력한 자극은 삼투압의 변화와 유효혈장량의 변화이다. 4. 나트륨 밸런스는 나트륨 섭취욕구에 의해서는 큰 영향을 받지 못하며, 주로 신장에 의한 염분배출조절에 의하며 이루어지고, 사구체 여과율과 알도스테론 분비가 신장의 나트륨 배설량을 결정하는 가장 중요한 인자이다.

• Korean Chemical Engineering Research
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• 제56권3호
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• pp.388-403
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• 2018

본 연구는 소듐냉각고속로 원형로 소듐-물 반응 압력완화계통의 소듐, 물, 가스 배출배관 설계에 필요한 요건 도출을 목적으로 한다. 증기발생기의 전열관 파단에 의한 대규모 물 누출 사고 발생 시, 증기발생기 전열관 측의 물과 전열관 외측의 소듐 및 반응생성물을 물배출조와 소듐배출조로 신속하게 배출하기 위해 증기발생기의 소듐 배출배관 파열판 면적, 소듐배출조의 가스 방출배관 직경, 물배출조의 기체 방출배관 직경, 증기발생기의 물 배출배관 직경 등을 설정하기 위한 계산을 수행하였다. 이를 바탕으로 대규모 물 누출 사고 발생 시 증기발생기 내 유체 배출 소요시간 및 압력거동 해석을 수행하였고, 증기발생기 물 배출배관 격리밸브의 차단 설정압력 등의 설계인자를 도출하였다. 본 연구에서 도출된 설계인자들은 소듐냉각고속로 원형로 소듐-물 반응 압력완화계통 설계에 기초자료로 활용할 예정이다.

• Nuclear Engineering and Technology
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• 제48권4호
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• pp.952-964
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• 2016

The prototype generation IV sodium-cooled fast reactor (PGSFR) has been developed by the Korea Atomic Energy Research Institute. This reactor uses sodium as a reactor coolant to transfer the core heat energy to the turbine. Sodium has chemical characteristics that allow it to violently react with materials such as a water or steam. When a sodium-water reaction (SWR) occurs due to leakage or breakage of steam generator tubes, high-pressure waves and corrosive reaction products are produced, which threaten the structural integrity of the components of the intermediate heat-transfer system (IHTS) and the safety of the primary heat-transfer system (PHTS). In the PGSFR, SWR events are included in the design-basis event. This event should be analyzed from the viewpoint of the integrities of the IHTS and fuel rods. To evaluate the integrity of the IHTS based on the consequences of the SWR, the behaviors of the generated high-pressure waves are analyzed at the major positions of a failed IHTS loop using a sodium-water advanced analysis method-II code. The integrity of the fuel rods must be consistently maintained below the safety acceptance criteria to avoid the consequences of the SWR. The integrity of the PHTS is evaluated using the multidimensional analysis of reactor safety-liquid metal reactor code to model the whole plant.