• Nuclear Engineering and Technology
• /
• 제56권3호
• /
• pp.1091-1099
• /
• 2024

Fluoride-salt-cooled High-temperature Reactor (FHR) is a promising nuclear reactor technology. Among many challenges presented by the molten fluoride salts is the corrosion of salt-facing structural components. Higher moisture contents, in the FLiNaK (LiF-NaF-KF, 46.5-11.5-42 mol%) salt, aggravate intergranular corrosion and pitting for the given alloys. Therefore, several thermal dehydration tests of FLiNaK salt were performed with a batch size suitable for thermal-hydraulic experiments. Thermogravimetric Analysis (TGA) was performed for the three constituent fluoride salts individually. Preliminary thermal dehydration plans were then proposed for NaF and KF salts based on the TGA curves. However, the dehydration process may not be required for LiF since its low mass loss (<1.3 wt%). To evaluate the performance of these thermal dehydration plans, a batch-scale salt dehydration test facility was designed and constructed. The preliminary thermal dehydration plans were tested by varying the heating rates, target temperature, and holding time. The sample mass loss data showed that the high temperatures (>500 ℃) were necessary to remove a significant amount of moisture (>1 wt%) from NaF salt, while relatively low temperatures (around 300 ℃) with a long holding time (>10 h) were sufficient to remove most of the moisture from KF salt.

• 한국식품저장유통학회지
• /
• 제6권1호
• /
• pp.55-60
• /
• 1999

A three variables by three level factorial design and response surface methodology were used to determine optimum conditions for osmotic dehydration of banana. The moisture loss, solid gain, weight loss and reduction of moisture content after osmotic dehydration were increased as temperature, sugar concentration and immersion time increased. The effect of concentration was more significant than those of temperature and time on mass transfer. Color difference and titratable acidity were decreased by higher concentration. Sweetness was increased by increasing sugar concentration, temperature, immersion time during osmotic dehydration. The regression models showed a significant lack of fit (p>0.5) and were highly significant with satisfying values of R2. To optimize osmotic dehydration, based on surface response and contour plots, superimposing the individual contour plots for the response variables. the optimum conditions for this process wire 26$^{\circ}C$, 44 $^{\circ}$brix and 2 hrs for moisture content, sweetness and color difference are less than 72%, 24 obrix and 10 degree.

• 여성건강간호학회지
• /
• 제21권1호
• /
• pp.23-31
• /
• 2015

Purpose: The purpose of this study was to investigate the effect of dehydration from preoperative fasting on postoperative nausea and vomiting in patients who underwent gynecologic surgeries. Methods: Study design was a prospective descriptive study. A total of 75 patients in a university hospital were selected. Data were collected from March 17 to May 16, 2014 using self-report questionnaires and clinical electronic chart. Results: Factors influencing the development of postoperative nausea and vomiting were type of surgery (t=3.44, p=.001), use of PCA (t=-2.16, p=.034), and preoperative dehydration level (t=5.93, p<.001), and these variables accounted for 51.7% of postoperative nausea and vomiting. Among these variables, preoperative dehydration amount (${\beta}=.56$) showed the largest influence in the difference in postoperative nausea and vomiting. Conclusion: Reducing dehydration during preoperative fasting can prevent occurrence of postoperative nausea and vomiting. Development of a clinical guideline is necessary to give directions for the prevention of dehydration during preoperative fasting and to ensure the proper duration of fasting according to patient characteristics, type of surgery and time of surgery.

• 자원리싸이클링
• /
• 제10권6호
• /
• pp.43-52
• /
• 2001

This study was conducted to obtain granular crystalline gypsum that can be used as raw material for Plaster boards or cements from waste Plaster board. Gypsum could be Preferentially disintegrated to gypsum needle in $10\mu\textrm{m}$ or less size by hydration after the dehydration of crushed waste Plaster board. The finer the gypsum needle, it is easier to remove coarse impurities and to recover the gypsum needle. The optimum conditions for obtain the finer gypsum size were dehydration rate of 75~85%, solid concentration at hydration of 10~15%, agitation speed of 250~400 rpm, crushing size before dehydration of 2 cm or less. Gypsum of 98.21% grade was recovered with 99.0% yield as the undersize of 325 mesh wet screening followed by the dehydration-hydration process performed at the conditions of dehydration rate of 80%, solid concentration at hydration of 15%, agitation speed of 300 rpm, crushing size before dehydration of 2 cm or less. After the recrystallization of recovered gypsum, Plate-like gypsum of $151\mu\textrm{m}$ size with 99.49% grade was obtained as the oversize of 270 mesh in a wet screening.

• 동아시아식생활학회지
• /
• 제27권4호
• /
• pp.477-490
• /
• 2017

The objective of this study was to analyze the relationship between blood pressure and serum mineral concentration in hypertension patients subjected to dehydration. The data were collected and analyzed for 7,109 patients who visited a hospital for their health checkup from 2011 till 2015. Respondents were classified into four groups depending upon their state of hypertension and dehydration: control group (no hypertension and no dehydrated), dehydrated group, hypertension group, and dehydrated with hypertension group. Hypertension group was found to have higher levels of serum sodium, calcium, and uric acid than the normal group, whereas the dehydrated group was found to have higher levels of serum sodium and potassium than the normal group. In effect, no significant correlation was directly observed between the hypertension group and dehydration group. However, there were significant negative correlations between dehydration of the old-aged group and their serum mineral concentrations, which are reportedly related to hypertension. Thus, dehydration prevention measures in the elderly over 65 could mitigate hypertension problems.

• 한국식품영양과학회지
• /
• 제27권5호
• /
• pp.903-907
• /
• 1998

Mass transfer characteristics during osmotic dehydration of mushrooms(Agaricus bisporus) in sugar solution were studied as a function of sugar concentration, immersion time and temperature, and the effect of osmotic dehydration on browning inhibition of air-dried mushrooms was also evaluated. Increasing the sugar concentration, immersion time and temperature increased moisture loss, sugar gain, molality and rate parameter. The changes of sugar gain and rate parameter were more significantly affected by concentration than by temperature of sugar solutions, while 1$0^{\circ}C$ increase in temperature or 10 Brix increase in concentration had the same effect on water loss. Water loss, sugar gain, molality were rapid in the first period of osmotic dehydration especially in the case of higher concentration and temperature of sugar solutions. Effects of osmotic dehydration in sugar solution(60 Brix, 8$0^{\circ}C$) with 18 min of immersion time(O.D.=0.099) rior to air dehydration on browning inhibition of dried mushrooms were more significant than blanching in water(8$0^{\circ}C$) with the same immersion time(O.D.=0.330) and the control (O.D.=0.559).

• 한국식품영양과학회지
• /
• 제19권3호
• /
• pp.195-200
• /
• 1990

Effects of cooking time(5-30 min in a pressure cooker) and HTST air dehydratiion time(0-9min at 15$0^{\circ}C$) on physical properties of dried green peas(3% oisture content wet basis) were investigated by determining rehydration ratio rehydration curve browning reaction and puncture force, The rehydration ratio and curve of dried green peas were increased with increa-sing cooking time and HTST air dehydration time. Preheating of the green peas for 30 min in a pressure cooker or for 9 min of HTST air dehydration time prior to 6$0^{\circ}C$ air dehydration recovered a 87.3% of original moisture content of raw green peas in a boiling water for 5 min. The brownin greaction was gradually decreased up to 15 min of cooking time. Puncture pressure of rehydrated green peas treated in a boiling water for 5 min was decreased as the cooking time and HTST air dehydration time were increased and was highly correlated with rehydration (r=-0.956) The effects of cooking time and HTST air dehydration time on rehydration ratio browning reaction and puncture pressure were significantly different at the a=0.01 level except effect of HTST air dehydration time on browning reaction.

• 대한보건연구
• /
• 제44권4호
• /
• pp.35-49
• /
• 2018

연구목적: 본 연구의 목적은 종합건강검진 수검자의 신체측정과 혈액검사를 통해 탈수 위험요인에 대해 조사하는 것이다. 연구방법: 연구 분석을 위해 Sodium ($Na^+$), BUN (Blood Urea Nitrogen) 및 FBS (Fasting Blood Sugar)의 데이터가 유효한 5,391개의 샘플을 선택하여 혈장삼투압 탈수지표를 계산하였다. 조사 데이터는 2014.01.01과 2015.12.31사이에 삼육서울의료원 종합건강검진센터를 방문한 검진 수검자로부터 수집되었다. 탈수와 연령, 체질량지수(BMI), 질병노출(고혈압, 당뇨병, 이상지질혈증, 신장장애)의 관계를 성별로 구분하여 분석하였다. 연구결과: 탈수 교차비는 남성과 여성 모두 50대 이상 연령부터 통계적 유의성이 나타났다. 비만여성은 탈수에 취약했으나 남성은 BMI 차이에 통계적 유의성이 나타나지 않았다. 질병에 노출된 그룹(고혈압, 당뇨병, 이상 지질 혈증, 신장 장애)은 탈수에 취약하였다. 또한 질병노출 수가 많을수록 교차비가 높아 탈수 위험도가 높은 것으로 나타났다. 결론: 노화, BMI증가, 질병노출은 탈수에 취약하게 하는 위험요인으로 나타났다. 50세 이후 연령대는 탈수예방을 위해 BMI와 만성질환 조절에 특별한 주의가 요구된다. 질병발생에 잠재적인 자극 메커니즘으로 혈장 삼투압 증가에 영향을 끼치는 탈수 위험요인에 대한 추가 연구를 제안한다.

• 한국식품과학회지
• /
• 제42권4호
• /
• pp.398-406
• /
• 2010

분자압축탈수 방법을 이용하여 기존의 다른 건조방법보다 우수한 탈수 및 건조된 생강을 얻고자 생강을 이용한 분자압축탈수법에 탈수제(maltodextrin) 첨가량, 탈수시간, 절단 두께를 다르게 한 후 반응표면분석법으로 최적화하여 생강의 탈수 및 건조 최적조건을 얻고자 하였다. 분자압축탈수 방법을 이용한 생강의 탈수제 첨가량을 증가시킬수록 탈수율, 복원율, 관능적 특성의 외관(external), 향기(flavor), 조직감(texture) 및 전체적인 기호도(overall acceptability) 등은 증가하였으나 색(color)의 경우 낮아졌다. 또한 탈수시간, 절단 표면을 증가시킬수록 탈수율, 복원율, 관능적 특성이 증가하는 경향을 나타내었다. 분자압축탈수를 이용한 생강의 최적조건 범위는 탈수제 첨가량이 70-82%, 탈수시간이 5.2-9.2시간 이고 절단 두께가 1.0-1.2 mm로 설정되었다. 따라서 분자 압축탈수 방법을 이용한 생강의 최적 탈수 및 건조조건은 탈수제 첨가량이 76%, 탈수시간 7.2시간, 절단 두께 1.1 mm가 적당한 것으로 나타났다.

• 한국식품저장유통학회지
• /
• 제17권3호
• /
• pp.358-364
• /
• 2010

분자압축 탈수공정에 의한 색도변화는 재사용 탈수액을 적용한 건조공정에서 원물과 유사한 색도를 나타내었다. 수분 및 수분활성도에서도 유의적 경향이 일치하였다. 탈수액의 농도와 첨가량에 의한 탈수율과 복원율의 변화에서는 탈수액의 농도 차이에 따라 탈수율은 달라졌으며 농도가 커질수록 탈수율이 증가하는 경향을 나타내었다. 복원율 역시 탈수액 농도가 낮을수록 완만한 복원율을 나타내었고 탈수액의 농도가 높을수록 복원율이 높았다. 탈수액의 첨가량에 의한 탈수율과 복원율에 변화에서는 첨가량이 다른 탈수제 차이에 따라 탈수율과 복원율이 달라졌으며 첨가량이 커질수록 탈수액 농도와 같이 뚜렷하게 탈수율이 증가하고 복원율이 높게 나타났다. 관능평가를 통하여 탈수액의 농도와 첨가량별 탈수액을 적용하여 분자압축 탈수건조한 생강시료를 비교 하였을 때 모든 항목에서 열풍건조가 가장 낮았고 외관의 경우에서는 동결건조한 시료가 우수하였지만 전체적인 평가에 있어서 탈수액을 이용하여 건조한 생강이 가장 우수하였다. 이 처럼 모든 품질평가 항목의 결과를 통하여 탈수액을 적용한 건조방법이 열풍건조와 동결건조보다 품질이 우수하고 시설과 가격에서 경쟁적으로 우수하며 활용가치와 기존의 건조방법의 단점을 보완해 주는 건조 방법으로 판단이 되어진다.