• 성인간호학회지
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• 제21권2호
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• pp.141-154
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• 2009

Purpose: The purpose of this study was to compare the difference of change in oxygen saturation, vital signs and suction time taken for the suctioning during endotracheal suctioning performed with closed suction system and with opened suction system. Methods: Data were collected from 31 adult patients with ventilator treatment who were admitted to a university hospital in Seoul and the collection period was from July 1 to November 15, 2005. Oxygen saturation, heart rate, respiration rate and mean arterial pressure were collected immediately prior to the suctioning intervention, during and 1 and 5 minutes after the suctioning from opened suction system and closed suction system. Results: 1) The difference in oxygen saturation was statistically significant in recovery time for oxygen saturation to return to baseline values after suctioning was significantly rapid on closed suction system (p<.05). 2) The difference in heart rate, respiration rate and mean arterial pressure was statistically insignificant 3) The suction time was shorter in closed suction system. Conclusion: Closed suction system is more efficient, as compared with the open suction system in the ventilator treatment.

• 한국농공학회논문집
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• 제54권4호
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• pp.93-103
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• 2012

A suction-saturation control technique based on flow pump system was developed to investigate hydraulic properties in unsaturated soils. The flow pump system is designed based on the principle of the axis-translation technique and triaxial equipment, and gives the suction-time and suction-saturation curves, the primary relationship needed for interpreting the response of unsaturated soils and link between theory and the material properties in unsaturated soil mechanics. Using the suction-saturation control technique, suction-time relationship and soil-water retention curve (SWRC) during hydraulic hysteresis were investigated with different net confining pressures and porosities. Three types of soils-two sands and a silt were used in this paper. This paper showed the effect of the hysteresis on the SWRC due to different net confining pressures and porosities. This means that a careful decision must be made as to which condition is to be modeled, since the delicate difference of the conditions in physical modeling can cause the different experimental output.

• 한국지반공학회논문집
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• 제32권7호
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• pp.15-24
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• 2016

보은 화강암 풍화토에 대한 불포화 특성을 조사하기 위하여 자동 흙-함수특성곡선 시험장치를 이용하여 건조 및 습윤과정에 따른 모관흡수력과 체적함수비를 측정하였다. 이를 토대로 van Genuchten(1980)의 방법을 이용하여 흙-함수특성곡선(SWCC)을 산정한 결과 유효포화도에 따른 모관흡수력은 S자형의 비선형적인 관계를 나타내며, 건조 및 습윤과정을 거치는 동안 이력현상이 발생되었다. Lu and Likos(2006)의 방법을 이용하여 흡입응력특성곡선(SSCC)을 산정한 결과 유효포화도가 낮은 경우 건조과정의 흡입응력은 일정하게 유지되나 습윤과정의 흡입응력은 증가하는 경향을 보인다. 그러나 유효포화도가 큰 경우에는 동일한 유효포화도에서 건조과정의 흡입응력이 습윤과정의 흡입응력보다 크게 발생되었다. 한편 계수추정방법의 하나인 van Genuchten(1980)의 방법을 이용하여 투수계수함수(HCF)를 산정한 결과 모관흡수력이 증가함에 따라 불포화 투수계수는 감소하며, 모관흡수력에 따른 불포화 투수계수의 감소 속도는 건조과정이 습윤과정보다 더 크게 발생됨을 알 수 있다.

• 한국농공학회지
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• 제45권6호
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• pp.153-161
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• 2003

The purpose of this paper is to investigate the soil-water characteristic curves for an unsaturated soil. To this ends, a series of suction measured test was conducted on the selected 4 kinds of soils taken from different sites of Korea, using modified pressure plate apparatus. Form the test results, the water contents, degree of saturation and volumetric water contents were analyzed with the suction. And the soil-water characteristic curves of unsaturated soil were drawn from the test results for various factors. The characteristic curves drawn with water content vs matric suction were classified certainly the difference in wet side but were not classified in dry side. The characteristic curves drawn with degree of saturation vs matric suction for unsaturated soil were shown the opposite inclination as compared with the former curve. But the characteristic curve with volumetric water content vs matric suction was described suitably not only in wet side condition but also in dry side. And it was found that the volumetric water contents of loose soil was high at the initial condition but that of dense soil was high at final condition (dry side).

• Child Health Nursing Research
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• 제16권2호
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• pp.128-135
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• 2010

Purpose: This study aimed to confirm the effect of routine suctioning at a nursery for healthy newborns who have undergone immediate oronasopharyngeal bulb suctioning after birth in a delivery room through the observation of their oxygen saturation level, heart rate, respiration rate, the vomiting sign, and the number of instances of vomiting. Methods: Data were collected for 62 days from March 15 to May 15, 2009 at the nursery of a hospital located in Seoul. One hundred forty newborns were assigned to one of three groups: a no suction group, an oropharyngeal suction group, or a orogastric suction group. Collected data were analyzed with the SPSS WIN 15.0 program using ANOVA, cross tabulations and an independent 2-sample t-test. Results: Routine suctioning to healthy newborns resulted in decreasing oxygen saturation levels and increasing the heart and respiration rate regardless of the kind of suctioning. Stabilization of the oxygen saturation level and vital signs was also observed without suctioning. Conclusion: To prevent healthy newborns from the side effect of suctioning, selective suctioning is recommended.

• Nuclear Engineering and Technology
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• 제53권3호
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• pp.1041-1048
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• 2021

An engineered barrier system (EBS) for the disposal of high-level radioactive waste (HLW) is composed of a disposal canister with spent fuel, a buffer material, a gap-filling material, and a backfill material. As the buffer is located in the empty space between the disposal canisters and the surrounding rock mass, it prevents the inflow of groundwater and retards the spill of radionuclides from the disposal canister. Due to the fact that the buffer gradually becomes saturated over a long time period, it is especially important to investigate its thermal-hydro-mechanical-chemical (THMC) properties considering variations of saturated condition. Therefore, this paper suggests a new method of measuring thermal conductivity and water suction for single compacted bentonite at various levels of saturation. This paper also highlights a convenient method of saturating compacted bentonite. The proposed method was verified with a previous method by comparing thermal conductivity and water suction with respect to water content. The relative error between the thermal conductivity and water suction values obtained through the proposed method and the previous method was determined as within 5% for compacted bentonite with a given water content.

• 한국지반공학회논문집
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• 제27권8호
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• pp.31-37
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• 2011

본 연구에서는 정적 다짐된 자연 성해 실트질 모래의 불포화 흡수력의 영향과 변형특성을 평가하기 위해서 불포화 일축압축시험을 수행하였다. 공시체는 초기포화도를 다르게 하여 제작되었고 공시체의 초기 흡수력 및 최대일축압축강도에서의 흡수력 그리고 전단시의 체적변형이 측정되었다. 시험결과, 초기포화도의 크기에 따라 흡수력, 최대 일축 압축강도 및 체적변형 거동을 살펴보고 평가할 수 있었다. 또한, 불포화상태 실트질 모래의 전단강도에서 흡수력에 의해 증가하는 겉보기 점착력을 나타내는 흡수응력($P_s$을 추정하였다.

• 한국농공학회논문집
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• 제46권6호
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• pp.61-69
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• 2004

The aim of the work described in this paper was to confirm the application of the equation of the soil-water characteristic curves on an unsaturated soil. A series of suction test for unsaturated soils was conducted on the selected 4 kinds of soil using modified pressure extractor apparatus. And it was carried out to analyse The experimental parameters which can be describe the soil-water characteristics, were determined by using the data obtained from the experiment. From the results, it was found that The matric suction varied according to the grain size distribution, amount of fine grain particles and void ratio. Also it was found that the residual degree of saturation was decreased with in crease of the void ratio, but the pore size distribution index and air entry value were increased with in crease of the void ratio. And The application of the soil-water characteristic curve equation was confirmed for the various conditions and the various state by the comparison between the measured degree of saturation and the predicted degree of saturation.

• 한국농공학회논문집
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• 제48권1호
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• pp.71-79
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• 2006

In Korea, most landslides occurred during the rainy season and had a shallow failure plane parallel to the slope. For these types of rainfall-induced failures, the most important factor triggering slope unstability is decrease in the matric suction of unsaturated soils with increasing saturation depth by rainfall infiltration. The saturation depth was readily estimated using modified Green-Ampt model proposed by Chu et al. (Chu Model) at present. But Chu Model involves some problems for application, because water-redistribution phenomena were not effected. So the modified Chu Model (MCGAM) which reflect water redistribution phono mens was developed. The results showed that the MCGAM had a better agreement with measured volumetric water contents than existing Chu Model.

• 한국지반공학회논문집
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• 제24권6호
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• pp.37-44
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• 2008

낮은 응력 상태에서 모래의 인장강도는 포화도 또는 흡입력에 따라 증가하다 최대값이 이른 후 감소한다. 최대인장 강도는 어느 포화도에서든 발생될 수 있다. 선행 연구에서는 이와 같은 습윤 모래의 인장강도를 정확히 표현한 이론이 제시되었다. 본 연구에서 세 가지 종류의 모래(워싱턴 주 시애틀의 검정 Esperance모래, 오스트리일리아 서부 Perth 해변 모래, Ottawa 모래)에 대해 실시된 일축인장실험, 함수특성실험, 직접전단실험 결과를 이용하여 제안된 이론을 검증하였다. 제안된 닫힌 형식의 식으로 표현된 이론은 이들 모래들로부터 얻어진 실험결과와 비교 시 전체 포화도 영역에서 인장강도 변화양상, 인장강도 크기, 최대인장강도, 최대인장강도가 발생할 때의 해당 포화도 등을 잘 예측하는 것으로 나타났다.