• Nuclear Engineering and Technology
• /
• v.56 no.3
• /
• 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.

• Food Science and Preservation
• /
• v.6 no.1
• /
• 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.

• Women's Health Nursing
• /
• v.21 no.1
• /
• 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.

• Resources Recycling
• /
• v.10 no.6
• /
• 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.

• Journal of the East Asian Society of Dietary Life
• /
• v.27 no.4
• /
• 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.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.27 no.5
• /
• 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).

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.19 no.3
• /
• 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.

• Korean Public Health Research
• /
• v.44 no.4
• /
• pp.35-49
• /
• 2018

Objective : The purpose of this study was to investigate the risk factors of dehydration from the subjects who underwent anthropometric and blood parameters testing during a comprehensive health screening. Methods : For the study analysis, 5,391 samples with valid data of the levels of Sodium($Na^+$), BUN (Blood Urea Nitrogen) and FBS(Fasting Blood Sugar) were selected to calculate a dehydration indicator of plasma osmolality. The study data was collected from the health screening examinees who visited Sahmyook Medical Center Seoul Adventist Hospital Comprehensive Health Check-up Center from 2014.01.01 to 2015.12.31. The relationship between dehydration and age group, BMI, disease exposures(hypertension, diabetes mellitus, dyslipidemia, kidney disorder) were analyzed by gender. Results : The odds ratio of dehydration showed statistical significance from age ${\geq}50$ in both male and female, respectively. The female obese group was vulnerable to dehydration while the male study group showed no statistical significance in the BMI difference. The disease exposed groups(hypertension, diabetes mellitus, dyslipidemia, kidney disorder) were vulnerable to dehydration. Also, the more types of disease carried by the exposed patients, the higher odds ratio and susceptibility to dehydration. Conclusions : Aging, increasing BMI, and exposed to diseases were found to be the risk factors for vulnerability to dehydration. To prevent dehydration, special caution to be taken for those in the ${\geq}50s$ group, along with controlling BMI and chronic diseases. Further studies are suggested to investigate the risk factors of dehydration that may affect increasing plasma osmolality as a potential stimulus mechanism in disease outbreaks.

• Korean Journal of Food Science and Technology
• /
• v.42 no.4
• /
• pp.398-406
• /
• 2010

The purpose of this study was to determine the optimal mixing ratios for three different concentrations of maltodextrin, dehydration time, and cutting thickness to prepare gingers using molecular press dehydration (MPD) through response surface methodology (RSM) based on the dehydration rate, rehydration rate, and a sensory evaluation. As maltodextrin concentration increased, dehydration rate, rehydration rate, external, flavor, texture, overall acceptability of the gingers tended to be high, and the color tended to be low. As the dehydration time and cutting thickness increased, dehydration rate, rehydration rate and the sensory evaluation of the gingers tended to be high. The maltodextrin concentrations were 70-82%, dehydration time was 5.2-9.2 hr, and cutting thickness levels were 1.0-1.2 mm. The optimal mixing ratios, maltodextrin concentration, dehydration time, and cutting thickness for manufacturing the best quality of gingers using molecular press dehydration were 76%, 7.2 hr, and 1.1 mm, respectively.

• Food Science and Preservation
• /
• v.17 no.3
• /
• pp.358-364
• /
• 2010

Ginger was dried using maltodextrin or recycled dehydration liquid as dehydrating agents, and the quality of dried ginger was compared with that of freeze-dried and hot-air-dried samples in terms of color, moisture content, water activity, dehydration rate, rehydration rate, and sensory properties. Ginger prepared using molecular press dehydration (MPD) retained its original color. The dehydration rate increased when ginger was dried using a dehydrating agent. The rehydration rate was increased in ginger dried using such an agent. Both dehydration and rehydration rates were elevated with increasing concentrations of soluble solids in the dehydration liquid. The sensory qualities of ginger prepared using the MPD method were better than those of freeze-dried and hot air-dried samples. These results indicate that drying of ginger rhizomes using recycled dehydrating liquid is very efficient.