• The Journal of Engineering Geology
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• v.32 no.2
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• pp.209-219
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• 2022

To experimentally investigate the variation of soil characteristics in slope during rainfall and the shape of slope failure, the model test was performed using soil box and artificial rainfall simulator. The model test of slope formed by the homogenous sand was performed, and the saturation pattern in the model slope due to rainfall infiltration was observed. The slope model with the inclination of 35° was set up on the slope of 30°, and the rainfall intensity of 50 mm/hr was applied in the test. The soil depth of 35 cm was selected by considering the size of soil box, and the TDR (time domain reflectometry) sensors were installed at various depths to investigate the change of soil characteristics with time. As the result of model test, the slope model during rainfall was saturated from the soil surface to the subsurface, and from the toe part to the crest part due to rainfall infiltration. That is, the toe part of slope was firstly saturated by rainfall infiltration, and then due to continuous rainfall the saturation range was enlarged from the toe part to the crest part in the slope model. The failure of slope model was started at the toe part of slope and then enlarged to the crest part, which is called as the retrogressive failure. At the end of slope failure, the collapsed area increased rapidly. Also, the mode of slope failure was rotational. Meanwhile, the slope failure was occurred when the matric suction in the slope was reached to the air entry value (AEV) estimated in soil-water characteristic curve (SWCC).

• Quality Improvement in Health Care
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• v.14 no.1
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• pp.55-59
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• 2008

Background : The purpose of inner cannula is to protect the upper air way and permit air to pass freely, in addition, to provide endotracheal suction, artificial respiration and to maintain adequate oxygen saturation. The tube needs to be sterilized for maintenance and cleanness of air way and for prevention of bronchospasm. However, it has been reported that there is no guideline for sterilization and many hospitals conduct their own sterilization methods, for example, once a day(13's general hospital), three times a day(The Catholic University of Korea ST Mary's hospital) or even no cleansing. Consequently, the QI team of our hospital suggested the SOP(standard operating procedure) of sterilization and evaluate cost and time effect in nursing. Method : 1) Benchmarking of 13's neurosurgery department of general hospital in Seoul 2) Investigation of test records of sputum culture from patients with intubation for tracheotomy 3) Check of results of O2 Sat. monitoring to confirm of maintaining opened air way Result : 1) Improvement of process: decrease of excess sterilization of inner cannula (from 3 times a day to once a day) 2) Cost effects: saving over 10 million won per one year 3) Providing better nursing: time effects (30 min a day) permit to conduct more nursing activities Conclusion : It can get Cost and time effects in nursing with improved sterilization method of inner cannula. It needs to do research on improvement of the monthly exchange protocol of outer cannula and provide supporting data for the proper exchange schedule. The result of additional microorganism detection from patients with new process needs to be evaluated further more.

• Journal of Korean Clinical Nursing Research
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• v.14 no.3
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• pp.73-85
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• 2008

Purpose: To examine effects of application of bronchodilators after endotracheal suction on peak air way pressure (PAP), lung compliance (Cdyn), oxygen saturation ($SpO_2$), heart rate (HR), blood pressure (BP), and respiration rate (RR) in cardiac surgery patients. Method: Data were collected from October 2007 to March 2008. Participants were patients who were treated with bronchodilators through mechanical ventilators in the SICU. At each suctioning, bronchodilators were applied immediately, and at 5, 10, and 15 minutes after suctioning. Besides PAP, Cdyn, $SpO_2$, HR, BP, RR, data on the frequency of side effects were also collected at 15, 30, 60 minutes after nebulization. Data were analyzed using the SAS program. Results: For application of bronchodilator right after suctioning and after, 5, 10 and 15 minutes, PAP and Cdyn did not show any significant differences although PAP was persistently decreased for 15 to 30 minutes and Cdyn increased at 15 minutes and decreased gradually after nebulization. Besides $SpO_2$, HR, BP, and RR, frequency of side effects did not show any significant difference. Conclusion: Bronchodilators can be applied at any time. However, the positive effects of bronchodilation right after suctioning on PAP and Cdyn, as also shown in previous reports, indicate it is a more efficient clinical process to maintain an adequate airway.

• Geotechnical Engineering
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• v.14 no.6
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• pp.33-44
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• 1998

Preliminary study has been conducted to analyse the co-relation between shallow landslides frequently occurring in rainy seasons and the water infiltration into the slope. The change of stress state due to partial saturation of a soil and hence the reduction of its shear strength have been reviewed. The variation of the safety factor of an infinite planar slope in accordance with various water infiltration scenarios has been estimated by limit equilibrium method to explain the mechanism of shallow slope failure. Numerical analysis under the same condition as those of some models dealt with in the previous method has been carried out by using FLAC, a finite difference program, and the results have been compared with the ones obtained by limit equilibrium method. Both results proved to be identical, which implies the ability of the numerical approach to the problems related to the stability analysis of unsaturated slope with the irregular geometry. Further improvement, however, should be made to apply the present analysis procedure to general slopes since it deals with a simple one.

• 아동간호학회:학술대회논문집
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• 1997.11a
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• pp.61-74
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• 1997

Endotracheal suctioning is a routine procedure used for clearing secretions from the airway of the intubated infant. This procedure is not without complications. Endotracheal suctioning has been associated with decreases in $PaO_2$, decreases in systemic venous oxygenation, alterations in mean arterial Pressure, disturbances in cardiac rhythm and development of nosocomial pneumonia. So several endotracheal suctioning techniques have been developed to prevent these blown complications. Another method of Endotracheal suctioning eliminates the risk associated with disconnecting the infant from the ventilatior to perform the suctioning procedure. Studies examining closed endotracheal suctioning methods reported that the closed method results in less arterial oxygen saturation, and less systemic venous oxygen desaturation. However those studies have focused on adult patients, and there have been no published studies for newborn infants. The specific purpose of this study is to investigate the two methods and to make a comparison in terms of (1)variations in $SaO_2$, heart rate, and respiration rate appeared before and after the endotracheal suctioning; (2)difference in occurrence of nosocomial infection; (3)difference in recovery time to arrive at pre-suction baseline after suctioning and in nursing time taken for the suctioning. The present study is based on the data obtained from two groups of newborn infants : one group comprises 8 infants with closed suctioning (a total of 304 suctions) among 17 infants treated with ventilator and the other group 9 infants with open method (a total of 629 suctions). The data were analyzed using the SPSS statistical program package. As the distribution test on dependent variables with the Skewnesser Shapiro Wilk test showed an asymmetric distribution, the Wilcoxon Matched-pairs Singled- Ranks test was used for the test of variations in $SaO_2$, heart rate, and respiration rate appeared before and after the endotracheal suctioning. The difference in $SaO_2$ recovery time and nursing time was analyzed with the Mann-Whitney U-Test. The difference in physiologic consequences and occurrence of nosocomial infection between the two groups was analyzed with the Fisher's Exact Test. The results of the study are summarized as follows. For the hypothesis 1 (There would be a difference in $SaO_2$, heart rate, and respiration rate before and after suctioning between the two suctioning methods), the difference in $SaO_2$ turns out to be statistically significant (P=0.015), but heart rate and respiration rate do not procedure a notable difference (P=0.630). The hypothesis 2 (There would be a difference in rates at which a complication arises after suctioning between the two groups) does not prove to be statistically valid (P=0.246). For the hypothesis 3(There would be a difference in $SaO_2$ recovery time and nursing time between the two groups), the average $SaO_2$ recovery time after suctioning turned out to have somewhat significant difference (P=0.064), however the difference in nursing time taken for the suctioning was not statistically significant (P=0.610). The analyses indicate that the closed endotracheal suctioning is more efficient as compared with the open method, in maintaining pre-suction baseline $SaO_2$ and a rapid recovery of newborn infants. Based on these results we suggust to apply the closed method to newborn infants in the ventilation treatment. We also suggest to extend the investigation to include the comparison of suction cost taking into account the case in which a complication arises after endotracheal suctioning between the two groups.

• Child Health Nursing Research
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• v.19 no.1
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• pp.1-11
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• 2013

Purpose: This study was done to develop a scenario and evaluate student performance in simulation learning of care for children with respiratory distress syndrome in neonatal intensive care units. Methods: To test the application effect, a one group pre-test design was applied. The scenario based on actual patients and textbook material was developed through several meetings of experts. The scenario was used with 17 groups of 55 senior nursing students who participated voluntarily. Results: Contents were organized focusing on the nursing process for simulation learning. In the application of knowledge and skills, nursing students had high scores in the contents of observation of oxygen saturation, and care to relieve dyspnea. Participants' ability, especially in suction and oxygen supply in the evaluation of objective structured clinical examination was not adequate. There was a significant positive correlation between problem-solving ability and satisfaction in learning. Conclusion: The respiratory distress syndrome simulation scenario developed in this study was an effective tool to give students experience in problem solving and critical thinking ability under conditions similar to reality. The development of various scenarios for child nursing care is needed.

• Tunnel and Underground Space
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• v.32 no.6
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• pp.518-529
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• 2022

In Task C of the DECOVALEX-2023 project, nine institutes from six nations are developing their numerical codes to simulate thermo-hydro-mechanical coupled behavior for the FE experiment performed at Mont Terri underground rock laboratory, Switzerland. Currently, Step 1 for comparing the simulation results to field data is the ongoing stage, and we used the OGS-FLAC simulator for a series of numerical simulations. As a result, temperature increase depending on the heating hysteresis was well simulated, and saturation variation in the bentonite depending on phase change was observed. However, due to the suction overestimation, relative humidity and temperature change in the bentonite and the pressure variation in the Opalinus clay showed a difference compared to the field data. From the observation, it is confirmed that the effect of the bentonite capillary pressure is dominant to the flow analysis in the disposal system. We further plan to draw improved results considering tunnel support material and accurate initial water pressure distribution. Additionally, the thermal, hydrological, and mechanical anisotropy of the Opalinus clay was well simulated. From the simulation results, we confirmed the applicability of the OGS-FLAC simulator in the disposal system analysis.

• Journal of Korean Academy of Nursing
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• v.25 no.3
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• pp.597-607
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• 1995

1960년대 이후 인공호흡기(mechanical ventilator)의 보급과 최근 의료과학의 발달, 간호의 질적 향상의 결과로 저체중출생아를 포함한 고위험 신생아의 생존율이 높아져왔다. 호흡장애증후군(RDS)은 일차적으로 폐포의 완전한 확장을 위해 필요한 계면활성물질(surfactant)의 부족, 미발달된 심폐기능에 의한 병리적 현상으로 저체중아의 가장 큰 원인이 되어왔다. RDS로 인해 인공호흡기에 의존해 있는 저체중아의 경우 적절한 산소공급과 이를 위한 호흡의 유지는 치료의 가장 큰 핵심이 되며, 이를 위한 기관내 흑은 비인두 흡인 (nasopharyngeal suction)은 신생아 중환자실(NICU)의 가장 중요한 간호행위가 되어왔다. 인공호흡기를 위한 기관삽관은 그 자체가 기도의 성모운동을 방해하고 기침반사를 억제시켜 폐 분비물의 효과적 배출을 억제하며, 특히 저체중아의 경우 조산과 관련하여 미발달된 흥곽운등과 심폐기능은 폐분비물의 이동을 저해하는 요소이다. 따라서 기도내의 분비물의 이동을 효과적으로 하여 흡인 시에 최대한의 효과를 돕기 위해 흥곽 물리요법(chest physiotheraphy : CPT)의 한 형태인 흉곽진동법 (Chest Vibration : CV)가 행해져 왔다. 그러나 저체중아를 위한CV의 임상적 적용은 그 대상의 생리적 특성, CV의 적용부위(site)와 기간(duration)에 대한 과학적 근거 없이 만성감염이나 폐질환을 가진 성인이나 cystic fibrosis환자를 위한 CV protocol을 무분별하게 채택하여 저체중아에게 행하여져 왔다 이에 본 연구자는 저체중아에 대한 CV의 안전성을 평가하고, 이에 기초하여 저체중아에게 바람직한CV의 형태를 알아보고자 본 연구를 시작하였다. 연구설계는 CV의 안전성을 평가하기 위한 실험연구이다. CV의 안전성은 RDS치료의 가장 일차적 목표인 oxygenation변화에 의해 평가될 수 있으므로, 본 실험 연구에서는 Pulse oximeter에 의해 계속적으로 측정된 산소포화 변화(oxygen saturation change)를 측정하였다. 실험대상은 미국동부에 위치한 대학병원의 NICU에 입원하여 RDS와 관련된 호흡장애로 인공호흡기에 의존해 있는 10명의 저체중아였다. 인공호흡기에 의존된 모든 저체중아는 Pulse oximeter와 심폐기능 측정기(cardiopulmonary monitor)에 의해 산소공급과 호흡상태가 계속 측정되고 있었다. 실험대상의 평균 출생시 몸무게는 평균 1,3050gm(SD=580.6)이었고, 임신월령 은 평균 28.6주(SD=3.1)였다. RDS가 그들의 일차적 진단명이었고, 그중 4명은 pneumonia, atelectasis의 합병증을 가지고 있었다. 10명중 6명은 intermittent mandatory ventilation(IMV)의 형태로, 4명은 continuous positive airway pressure(CPAP)의 형태로 인공호흡기에 의존되어 있었고 CV시의 FiO2는 평균 42.3(SD=21.2)였다. CV는 중환아용 소형진동기 (minivibrator)를 이용해 가각 10명 의 간호사에 의해 행하여 졌고, 최소 22초에서 최대 100초 동안 실시되었다. 50%의 간호사는 30초에서 40초간 CV를 실시하였으며, CV의 적용부위도, 전후 흉곽부위, 혹은 병변이 있는 좌 우측, 흑은 양쪽 흉벽 등으로 다양했고, 적용방법도 원형으로 돌려가며(circular motion), 혹은 아래에서 위로, 혹은 아무런 기준없이 간호사의 기호에 따라 다양하게 적용되었다. 산소포화의 변화는 CV가 행해지기 전.후로 5초동안 관찰되었다. 연구의 결과, 산소포화 변화는 비 모수통계(non parametric statistics)의 일종인 Matched Paired Wilcoxon test로 분석 한 결과 CV후에 3%의 감소를 보였다(P<.05). 저체중아에 있어 산소포화의 3%감소는 임상적으로 중요한 의미가 없다고 사료되어지며, 실제 흡인전의 과도호흡에 의해 CV를 행하기 이전의 산소공급수준으로 돌아 왔다. CV실시 기간과 산소포화와의 상관관계는 비 모수통계인 Spearman rho correlation coefficient를 이용하여 분석하였는데, 이 두 변수는 서로 관계가 없는 것으로 나타났다(P>.05) 또한 CV와 흡인 후에 각각의 간호사들에게 CV를 필요로 한 저체중아의 기준, 적용부위, 기간, 방법등에 대한 기준을 물었으나 대상의 특성에 따른 간호사정에 의존하기보다는 간호사 각자의 선호하는 방법이나 습관에 라 행하는 것으로 나타났다. 결론적으로 CV와 산소포화 변화와의 관계, NICU에서 관찰된 CV의 임상적 적용을 기초로 저체중아에게 안전한 CV protocol은 신생아용 소형 진동기를 이용하여, 양쪽 흉곽의 늑골하측 변연 부위(low lateral costal margin)에서 시작하여 흉골 중앙부위 방향으로 30초 동안 진동기를 적용하는 것이 좋은 것으로 나타났다. 이에 CV의 효과를 평가하기 위한 보다 과학적인 접근방법으로, CV와 흡인의 결과인 가래(sputum)에 대한 연구를 제언하는 바이다.