• Nutrition Research and Practice
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• 제7권3호
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• pp.192-198
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• 2013

Dietary sodium intake is considered one of the major causal factors for hypertension. Thus, to control the increase of blood pressure and reduce the risk of hypertension-related clinical complications, a reduction in sodium intake is recommended. The present study aimed at determining the association of dietary sodium intake with meal and snack frequency, snacking time, and taste preference in Korean young adults aged 20-26 years, using a 125-item dish-frequency questionnaire. The mean dietary sodium intakes of men and women were 270.6 mmol/day and 213.1 mmol/day, which were approximately 310% and 245% of the daily sodium intake goal for Korean men and women, respectively. Dietary sodium intake was positively correlated with systolic blood pressure in the total group, and BMI in the total and men-only groups. In the total and men-only groups, those who consumed meals more times per day consumed more dietary sodium, but the number of times they consumed snacks was negatively correlated with dietary sodium intake in the total, men-only, and women-only groups. In addition, those who consumed snacks in the evening consumed more sodium than those who did so in the morning in the men-only group. The sodium intake was also positively associated with preference for salty and sweet taste in the total and women-only groups. Such a high intake of sodium in these young subjects shows that a reduction in sodium intake is important for the prevention of hypertension and related diseases in the future.

• 조명전기설비학회논문지
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• 제18권5호
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• pp.27-34
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• 2004

본 논문에서는 half-bridge inverter를 이용하여 400[W] 고압나트륨 램프용 전자식 안정기를 설계하였다. 제안된 등가 LC 직렬 공진회로에서 인덕터와 커패시터의 값을 이론적으로 계산하고, LC 직렬 half-bridge 회로에 대한 IsSPICE 시뮬레이션을 수행하였다. 계산결과를 검증하기 위해 전자식 안정기를 설계 제작하여 실험을 수행하였다. 실험에 의한 전자식 안정기의 제반특성은 시뮬레이션 결과와 대단히 유사하였다. 실험결과 출력전압 400[W]에서 역률 99.3[%], 전류 전고조파 10.01[%], 램프효율 119[lm/W]의 좋은 성과를 나타내었다.

• 대한전기학회논문지
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• 제35권11호
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• pp.495-502
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• 1986

The change of the discharge characteristics of the high-pressure sodium (HPS) lamps is investigated over a power source frequency range of 60 Hz to 30, 000 Hz. As the frequency increases, the light and electrical characteristics of the HPS lamps are improved since the re-ignition is not needed due to the constant electron density, and the cathode fall is reduced. But at the certain frequency range, the arc instability called acoustic resonance occurs, and the arc tube is damaged. Regarding these characteristics and the kind of the illuminating system, a proper frequency is selected to operate the HPS lamps. And a new measuring system using a computer and the storage-scope is developed to avoid the error of the ordinary gauges at high frequency power.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 B
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• pp.1304-1306
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• 1996

A regenerative signal amplifying gate driver of self-excited electronic ballast is presented. It can be used for high pressure sodium (HPS) lamp without auxiliary external ignitor. Since the HPS lamp requires very high ignition voltage at start up, the resonant frequency of the circuit must be increased to obtain high voltage oscillations in spite of relatively small resonant current. The presented gate driver amplifies the current of gate drive transformer and raises the gate-source voltage Quickly to turn on the MOSFET switches. Hence, the resonant frequency can be increased more than 100kHz. The HPS lamp used in the simulation and experiment has the rating of 400W input power at 220V input ac voltage source. The experiments show that the resonant frequency is above 150kHz at start up.

• Bulletin of the Korean Chemical Society
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• 제7권3호
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• pp.163-166
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• 1986

A new paraffin salt bridge was developed for the concentration cell in high pressure system. The emf values of the concentration cells were measured to calculate the activity coefficients of the electrolytic ions depending upon the pressure of the system. The activity coefficients of sodium, chloride and bromide ions increase with the temperature of the cell and decreased, nearly half at 2500 bars, $20^{\circ}C$, with the pressure. These results can be explained to be attributed to the volume change of the hydrated ion due to the electrostriction. The volume change decreased with pressure due to an increase in the degree of the hydration.

• Nutrition Research and Practice
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• 제14권5호
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• pp.540-552
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• 2020

BACKGROUND/OBJECTIVES: Hypertension is the major risk factor for cardiovascular disease, a leading cause of deaths in Korea. The objective of this study was to evaluate the effect of a nutrition education in reducing sodium intake and increasing potassium intake in hypertensive adults. SUBJECTS/METHODS: Subjects who participated in this study were 88 adults (28 males and 60 females) who were pre-hypertension or untreated hypertensive patients aged ≥ 30 yrs in Gyeonggi Province, Korea. These subjects were divided into 2 groups: a lowsodium education (LS) group and a low-sodium high-potassium education (LSHP) group. Nutrition education of 3 sessions for 12 weeks was conducted. Blood pressure, blood and urine components, nutrient intake, and dietary behavior were compared between the two education groups. RESULT: Blood pressure was decreased in both groups after the nutrition education (P < 0.05). In the LSHP group, levels of blood glucose (P < 0.05), total cholesterol (P < 0.01), and lowdensity lipoprotein-cholesterol (P < 0.05) were decreased after the program completion. Sodium intake was decreased in both groups after the nutrition education (P < 0.05). However, Na/K ratio was only decreased in the LS group (P < 0.05). Intake frequency of fish & shellfish was only significantly reduced in the LS group (P < 0.05), while intake frequencies of cooked rice, noodles & dumplings, breads & snacks, stew, kimchi, and fish & shellfish were reduced in the LSHP group (P < 0.05). Total score of dietary behavior appeared to be effectively decreased in both groups after the education program (P < 0.001). CONCLUSIONS: This education for reducing sodium intake was effective in reducing blood pressure and sodium intake. The education for enhancing potassium intake resulted in positive changes in blood glucose and serum cholesterol levels.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제52권1호
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• pp.27-32
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• 2003

The thesis is used by PSpice circuit model to the characteristics of a fluorescent lamp modified form of he classical Cassie and Mayr equations in order to show the characteristics of HID(High-Intensity Discharge) Lamp. This is useful for applying high-frequency electric ballast for HID Lamp, and show that the result of experimentations and simulations, such as lamp rating, input voltage, high-frequency electric ballast which is using the ABM circuit model of the low pressure sodium lamp, come to the voltage and current wave.

• 대한의생명과학회지
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• 제11권3호
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• pp.275-279
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• 2005

High-salted mineral water (Daehan Deep Water, Korea) that is pumped up from below the sedimentary rock layer of Dadaepo, Busan, Korea has a composition similar with that of deep sea water. Under the well-being boom, the mineral water is processed for various uses including washing or oral administration. However, high concentrations of various minerals in the mineral water are suspected to affect on the physiology of human body, especially on blood pressure (BP). Here, we examined the effect of Hot Mineral(R), dried powder of the mineral water, on the change of BP. Sprague­Dawley rats were grouped and orally administered $2.5\%$ Hot Mineral(R) (group M), $2.5\%$ NaCl (group S) or normal water (group C). Excreted urine was collected in metabolic cage for 24 hours. The systolic blood pressure (SBP) of the group S was remarkably increased (P<0.005) compared with that of the group M and the group C, which showed little changes of the SBP during 2 weeks. While average daily sodium intake were 0.32 mg in the group C, 6.64 mg in the group M and 4.07 mg in the group S, average daily sodium excretion were 11.37 mg, 53.70 mg and 7.75 mg, respectively. These results indicate that the sodium excretion in the group M was much higher than the other two groups. In this study, we suppose that the plenty amount of minerals such as calcium, potassium and magnesium in Hot Mineral? have an effect not to increase the SBP and to prompt sodium excretion out of the body. Therefore, these results suggest that oral administration of appropriate amount of Hot Mineral(R) for limited period does not induce increased SBP.

• Geomechanics and Engineering
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• 제16권1호
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• pp.71-83
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• 2018

Compacted bentonites were chosen as the backfill material and buffer in high level nuclear waste disposal due to its high swelling pressure, high ion adsorption capacity and low permeability. It is essential to estimate the swelling pressure in design and considering the safety of the nuclear repositories. The swelling pressure model of expansive clay colloids was developed based on Gouy-Chapman diffuse double layer theory. However, the diffuse double layer model is effective in predicting low compaction dry density (low swelling pressure) for certain bentonites, and invalidation in simulating high compaction dry density (high swelling pressure). In this paper, the new relationship between nondimensional midplane potential function, u, and nondimensional distance function, Kd, were established based on the Gouy-Chapman theory by considering the variation of void ratio. The new developed model was constructed based on the published literature data of compacted Na-bentonite (MX80) and Ca-bentonite (FoCa) for sodium and calcium bentonite respectively. The proposed models were applied to re-compute swelling pressure of other compacted Na-bentonites (Kunigel-V1, Voclay, Neokunibond and GMZ) and Ca-bentonites (FEBEX, Bavaria bentonite, Bentonite S-2, Montigel bentonite) based on the reported experimental data. Results show that the predicted swelling pressure has a good agreement with the experimental swelling pressure in all cases.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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• pp.434-437
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• 1999

An EM pump is used for the purpose of transporting the electrically conducting liquid sodium of the high temperature that is used as a coolant in the liquid metal reactor. In the present study, the pilot pump has been designed and manufactured for the high temperature of $600^{\circ}C$ by the equivalent circuit materials and the consideration of the materials and functions. The length and diameter of the pump are given as 84 cm and 10 cm each due to the fixed geometry of the circulation system to be installed. The characteristic of the developing pressure and efficiency is found out by using Laithewaite\`s standard design formula. It is shown that the developing pressure and efficiency are maximized at the frequency of 15 Hz from the curve. The annular channel gap of 3.95 mm is selected in the range of the reasonable hydraulic frictional loss. The components of the pump consist of the material for the high temperature. And then, the pump is manufactured to have the nominal flowrate of 40 1/min and developing Pressure of 1.3 bar.