• 한국식품영양과학회지
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• 제24권4호
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• pp.493-501
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• 1995

To investigate an effect of dietary sodium and potassium on blood pressure, 418 adolescents living in Kangwha area were studied. Two measurements were taken on each blood pressure(diastolic, systolic) and the average of the two readings was used in the analysis. Sodium and potassium intake were estimated by the determination of those electrolytes in 24hr urine. Not only dietary factors but also physical growth factors such as weight, height, arm-circumference and skinfold-thickness were induced in the stepwise multiple regression analysis to indentify the relative importance between the factors. The variation of blood pressure both in systolic and diastolic in both sexes was inconsistent with the levels of sodium and potassium intake. The results of multiple regression analysis showed that the physical growth were more influential than nutrient factor. It suggested that hypertension risk factors observed form the adults, may not be identical with that of the growing aged population. After control of the physical growth, there was no significant variation observed by the level of sodium and potassium intake on blood pressure. In summary, the results indicate that growth has been more influential than dietary factor on blood pressure for growing aged population.

• 멤브레인
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• 제14권3호
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• pp.192-200
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• 2004

본 연구에서는 유기질막에 비해 안정성이 우수하고 사용수명이 긴 세라믹 막을 이용하여 혐기성 Lactobacillus 균주의 농축에 관해서 연구하였다. Cell harvesting (CH)에 영향을 주는 인자로 막투과 압력, 온도, 선속도 등에 대해 조사하였으며 세라믹 막을 이용하여 농축율 변화에 따른 플럭스와 TMP (transmembrane pressure)의 변화, 일정 VCF(volumetric concentration factor)에서 TMP변화 등의 최적조건에 관해 알아보았다. 그 결과 플럭스는 TMP, 선속도, VCF가 증가함에 따라 투과수량도 증가함을 알 수 있었다. 온도가 증가할수록 점도에 의해 초기 플럭스도 증가하지만 시간이 경과함에 따라 막 표면의 겔층의 형성으로 온도의 영향은 미미하였다. 또한 농축비 이하의 일정한 VCF에서 운전할 경우 플럭스가 안정적임을 알 수 있었다. 선속도 5 m/s, 공급액의 온도 $37^{\circ}C$, TMP 1 bar에서 6∼8 h 운전할 경우 PS 406 원액의 생균수는 4.9{\times}10^9$으로 약 8배 농축됨을 알 수 있었다.

• 한국콘텐츠학회논문지
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• 제9권10호
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• pp.176-185
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• 2009

본 연구는 골밀도검사를 받은 폐경 후 여성들을 대상으로 신체특징을 조사한 다음 혈압측정과 혈액검사를 실시하였으며, 총 653명을 대상으로 하였다. 통계 분석은 SPSS for Windows 프로그램(version 12.0)을 사용하였고, ANOVA 및 카이제곱으로 관련성을 비교분석하였으며, 변인 예측을 위해 선형회귀분석방법을 실시하여 다음과 같은 결론을 얻었다. 골밀도와 심혈관위험인자 중 신장, 체중, 체질량지수는 T-score와 유의한 양의 관계가 나타났고 (p<0.001), 연령, 수축기혈압, 이완기혈압, 총콜레스테롤, 고밀도지단백콜레스테롤, 중성지방, 혈당에서 T-score와 유의한 음의 관계가 있는 것으로 나타났으며(p<0.001), 골밀도에 가장 큰 영향을 미치는 변인은 체중(18.7%)으로 나타났다. 골밀도와 심혈관위험인자의 관계는 모두에서 유의한 관련성이 나타났다. 따라서 인구의 노령화와 함께 여성들에게서 골다공증 문제가 더욱 중요시되고 있는 추세이므로 골다공증의 발생기전을 규명하고 효율적인 예방 전략을 수립하기 위한 체계적인 연구의 시도가 계속되어야 할 것으로 사료된다.

• 한국결정성장학회지
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• 제19권3호
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• pp.116-124
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• 2009

Our computational studies for the physical vapor transport crystal growth of $Hg_2Cl_2-Cl_2$ system evidence suggests that the PVT growth process exhibits the diffusion-dominated behaviors for aspect ratios more than and equal to 10, which would provide purely diffusive transport conditions adequate to microgravity environments less than $10^{-3}g_0$. Also, the regimes of high temperature difference based on the fixed source temperature of $380^{\circ}C$, where ${\Delta}T$ is relatively large enough for the crystal growth of mercurous chloride, the transport rates do not keep increasing with ${\Delta}T$ but tend to some constant value of $2.12\;mole\;cm^{-2}s^{-1}$. For the aspect ratios of 5, 10, and 20, the transport rate is directly proportional to the total pressure of the system under consideration. For Ar = 5, the rate is increased by a factor of 2.3 with increasing the total pressure from 403 Torr to 935 Torr, i.e., by a factor of 2.3. For both Ar = 10 and 20, the rate is increased by a factor of 1.25 with increasing the total pressure from 403 Torr to 935 Torr.

• 설비공학논문집
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• 제11권4호
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• pp.549-559
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• 1999

An experimental study was peformed to measure the viscosity of microencapsulated PCM slurries as the functions of its concentration and temperature, and also influence to its fluid dynamics. For the viscosity measurement, a rotary type viscometer, which was equipped with temperature control system, was adopted. The slurry was mixed with water and Sodium Lauryl Sulphate as a surfactant by which its suspended particles were dispersed well without the segregation of particles during the experiment. The viscosity was increased as the concentration of MicroPCM particle added. The surfactant increased 5% of the viscosity over the working fluid without particles. Experiments were proceeded by changing parameters such as PCM particles'concentration as well as the temperature of working fluid. As a result, a model to the functions of temperature for the working fluid and its particle concentration is proposed. The proposed model, for which its standard deviation shows 0.8068, is agreed well with the reference's data. The pressure drop was measured by U-tube manometer, and then the friction factor was obtained. It was noted that the pressure drop was not influenced by the state of PCM phase, that is solid or liquid in its core materials at their same concentration. On the other hand, it was described that the pressure drop of the slurry was much increased over the working fluid without particles. A friction factor was placed on a straight line in all working fluids of the laminar flow regardless of existing particles as we expected.

• 대한조선학회논문집
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• 제33권1호
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• pp.19-26
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• 1996

프로펠러에 의한 선체변동압력을 추정하기 위해 3개의 선체에 7개의 프로펠러를 장착하여 실험과 계산치를 비교하였다. 변동압력의 계측은 KRISO의 공동터널에서 평판에 대하여 수행하였으며, 수치계산은 양력면 이론과 패널법을 사용한 수치프로그램(X-ForShip)을 사용하였다. 평판에 대한 실험값을 복잡한 선미형상에 적용하기 위하여 강체경계율(SBF)이 수정계수로 결정되었다. 실선 변동압력의 예측과 실험치의 수정을 위하여 복잡한 선미형상에서의 변동 압력을 계산하였다. 계산치와 수정된 실험치와의 좋은 일치를 보였으며, 수성계수로써 약 0.65-0.7의 값이 결정되었다.

• Wind and Structures
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• 제36권1호
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• pp.41-60
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• 2023

The effect of cladding panel size on the size reduction factor (SRF) of extreme area-averaging wind pressure (EAWP) on the facades of a high-rise building is often ignored in previous studies. Based on wind tunnel tests, this study investigated the horizontal and vertical correlations of wind pressure on the facade claddings of square-section high-rise buildings. Then, the influencing parameters on the SRF of the EAWP on the cladding panels were analyzed, which were the panel area, panel width, panel length and building width. The results show clear regional distinctions in the correlation of wind pressures on the building facades and the rules of the horizontal and vertical correlations are remarkably different, which causes the cladding size ratio to impact the SRF significantly. Therefore, this study suggests the use of the non-dimensional comprehensive size parameter b^𝜶h^1-𝜶/B (𝜶 is the fitting parameter) determined by the cladding panel horizontal size b, cladding panel vertical size h and the building width B rather than the cladding panel area to describe the variation of the EAWP. Finally, some empirical formula for the SRF of the EAWP on the cladding of a high-rise building is proposed with the nondimensional comprehensive size parameter.

• 대한기계학회논문집A
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• 제26권11호
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• pp.2390-2398
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• 2002

For integrity analysis of nuclear reactor pressure vessel, including the Pressurized thermal shock analysis, the fast and accurate calculation of the stress intensity factor at the crack tip is needed. For this, a simple approximation scheme is developed and the resulting stress intensity factors for axial semi-elliptical cracks in cylindrical vessel under various loading conditions are compared with those of the finite element method and other approximation methods, such as Raju-Newman's equation and ASME Sec. Xl approach. For these, three-dimensional finite-element analyses are performed to obtain the stress intensity factors for various surface cracks with t/R = 0.1. The approximation methods, incorporated in VINTIN (Vessel INTegrity analysis-INner flaws), utilizes the influence coefficients to calculate the stress intensity factor at the crack tip. This method has been compared with other solution methods including 3-D finite clement analysis for internal pressure, cooldown, and pressurized thermal shock loading conditions. The approximation solutions are within $\pm$2.5% of the those of FEA using symmetric model of one-forth of a vessel under pressure loading, and 1-3% higher under pressurized thermal shock condition. The analysis results confirm that the VINTIN method provides sufficiently accurate stress intensity factor values for axial semi-elliptical flaws on the surface of the reactor pressure vessel.

• 조명전기설비학회논문지
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• 제27권3호
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• pp.16-25
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• 2013

Now it's a trend to install a series of white fluorescent light and orange high pressure sodium lamps because tunnel lighting should be opaque to the safety of drivers from soot, dust, humidity, and fog. Also fluorescent lighting is replaced to LED due to the fact that it improves amenity and object recognition and LED lighting has gradually been improved its nature. In this paper, we have implemented the circuits of the yellow series of high-pressure sodium lamps and white series of LED lights at one board to improve the transparency and recognition of objects. It is possible for inductive high-pressure sodium lamps and the capacitive LED drivers to circuit without power factor compensation. Two circuit parts share only a small number of parts, so low cost LED drivers compared to conventional ones are possible. Therefore, the implementation of the hybrid lighting with high-pressure sodium lamps and LED lights that can be driven at the same time by one driving circuit is possible. The LED capacitive power factor was 0.91 while individually implemented the sodium lamp power factor was 0.98. It shows not only the 2% improvement of hybrid forms but also the efficiency and THD.

• Archives of Plastic Surgery
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• 제49권2호
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• pp.275-284
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• 2022

Background Population aging has led to an increased incidence of pressure ulcers, resulting in a social burden and economic costs. We developed a three-dimensional knitted fabric (3-DKF) with a pressure-reducing function that can be applied topically in the early stages of pressure ulcers to prevent progression. Methods We evaluated the effects of the 3-DKF in a streptozotocin-induced diabetes mellitus pressure ulcer mouse model, and the fabric was preliminarily applied to patients. Twelve-week-old male C57BL/6 mice were used for the animal experiments. In the pressure ulcer mouse model, an ischemia-reperfusion injury was created using a magnet on the dorsa of the mice. Pressure was measured with BodiTrak before and after applying the 3-DKF to 14 patients at risk of sacral pressure ulcers. Results In the 3-DKF-applied mice group, the ulcers were shallower and smaller than those in the control group. Compared with the mice in the control group, the 3-DKF group had lower platelet-derived growth factor-α and neutrophil elastase expression, as parameters related to inflammation, and increased levels of transforming growth factor (TGF)-β1, TGF-β3, proliferating cell nuclear antigen, and α-smooth muscle actin, which are related to growth factors and proliferation. Additionally, typical normal tissue staining patterns were observed in the 3-DKF group. In the preliminary clinical analysis, the average skin pressure was 26.2 mm Hg before applying the 3-DKF, but it decreased to an average of 23.4 mm Hg after 3-DKF application. Conclusion This study demonstrated that the newly developed 3-DKF was effective in preventing pressure ulcers through testing in a pressure ulcer animal model and preliminary clinical application.