• Ocean and Polar Research
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• 제38권4호
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• pp.331-338
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• 2016

Many studies using tracers have been conducted to understand a physical process in a system. Rain-on-snow could accelerate snowmelt processes, which influences the hydrological process in both temperate and polar regions. Hydrological and ecological conditions will be affected by the amount and timing of discharge reaching the bottom of a snowpack. The discharge consists of the rain-on-snow, pore water penetrating into the snowpack and natural meltwater. In this study, after a rain-on-snow experiment, we conducted an isotopic hydrograph separation to distinguish rainwater and pore water from meltwater. Using the isotopic data of snow and meltwater from Lee et al. (2010), two components were separated based on the assumption that rainwater and pore water are new water and natural meltwater is old water. After the second rain-on-snow experiment, the maximum contributions of rainwater and pore water reached up to 69% of the discharge and then decreased. During the study period, the measured total discharge was 4153 L and 40% (based on hydrogen isotope) of rainwater and pore water was calculated in the discharge, which is not consistent with what Lee et al. (2016) calculated using chemical separation (63%). This inconsistency can be explained by how an end-member was defined in both approaches. The contributions of artificial rainonsnow and pore water to melwater discharge range between the two methods. This study will suggest a mixing calculation from isotopic compositions of the Southern Ocean.

• 상하수도학회지
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• 제25권4호
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• pp.471-478
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• 2011

A series of laboratory experiments carried out to investigate the particle separation efficiency and flotation characteristics using $CO_2$ bubbles. The primary objective of this study was to find out the feasibility of $CO_2$ bubbles as an applicable unit of flotation process in tap-water and wastewater treatment plant. The fundamental measurements were conducted to characterize the $CO_2$ bubble from the physical viewpoint in water including bubble size distribution and rising velocity under various operational conditions. In addition, the removal efficiency of solid was experimented using the lab scale plant applied $CO_2$ bubbles, namely the dissolved carbon dioxide flotation (DCF) process. The DCF process using carbon dioxide bubble, which is an advantage as the decrease and the reuse of Green-House gas, can be a promising technology as an water treatment process. On the other hand, the further research to decrease the bubble size distribution of $CO_2$ is required to enhance the particle separation efficiency.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제3권1호
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• pp.138-146
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• 1992

선택적 함구증을 보인 6세 아동의 놀이치료 과정을 통해 나타난 정신역동 및 치료과정을 발달학적 관점에서 소개하였다. 비지시적 지지적 놀이치료를 실시하였고 치료자와의 관계속에서 환아는 놀이를 통하여 단계적으로 발달과정을 재경험하여 분리 불안 및 유기공포를 극복하고 자율성을 회복하므로써 증상의 소실과 함께 정상적 외디푸스시기의 발달을 이루게 되었다.

• 한국막학회:학술대회논문집
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• 한국막학회 1998년도 추계 총회 및 학술발표회
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• pp.63-65
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• 1998

1. Introduction : Atmospheric discharge of VOC-contaminated streams in chemical plants and air streams from chemical processes poses a serious environmental problem and entails large financial losses. Such emissions may be reduced by i) adsorption process, ii) absorption process and iii) incineration process. These processes only forbids the air pollutions. Throughout the recent decade, another technique-membrane process has emerged. The separation and recovery of organic vapors by membrane process may have great economic potential. Most of the published research works on the separation of organic vapors from air were performed using silicon rubber membranes. However, it is very difficult to fabricate very thin membranes with less than 1 $u m thickness. Plasma polymerization could be a good technique to generate a thin polymer film. The objective of this work is to find out the optimum condition of plasma polymerization for producing VOC separation membrane. For the objective, composite membranes are prepared through plasma polymerization of hexamethyldisiloxane onto porous substrates under different conditions. The membrane is then subjected to the permeation of permanent gases and VOCs to find the correlations between the physical properties of the penetrant and permeability and selectivity.

• 한국보건간호학회지
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• 제7권2호
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• pp.53-66
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• 1993

By this time, a few of previous studies of factors related to separation from their jobs and job satisfaction only have dealt with the separation rate. the cause of separation and related factors that induce job satisfaction and incentive factors, the actualities of morale some suggestions for reduction of the separation rate. This study is attempted to determine factors that have effect on job satisfaction of national hospital nurses. and to proide information and materials for the development of the administration of nursing through the appreciation of factors influencing on job satisfaction between isolated ward nurses and general ward nurses working at national hospitals. 185 nurses of national hospitals responsed th this study, and were divided into two groups. Group 1: 57 nurses working at isolated wards for tuberculosis patients and Group 2 : 128 nurses at general wards. Relevant data were collected from August, 5, 1992 through August 20, 1992. The questionnaire consisted of 8 genalized items and 4 items concerning job satisfaction. The collected data were processed with SPSS, and the relationship among vaviables was analyzed by means of $X^2-test$, Pearson Correlation, Multiple Regression. The results of this study are as follows: 1. There is no significant difference between two groups in terms of generalized items. Age distributions show $44.3\%$ under the category of less than 34. and $55.7\%$ under the category more than 35, $19.3%$ was single and $74.6\%$ was married respectively. 2. $79.4\%$ of the nurses have the desire to have in-service education under the satisfactory physical environments such as welfare system, accommodating structures and facilities, instruments or management systems of the hospital, but under the category of unsatisfactory circumstances, $60.3\%$ have the intention of having in- service education. The concern in terms of in-service education shows statistically significant difference between two groups $(X^2=8.85,\;p<0. 05)$. This result accepts the hypothesis that good physical environments could intensify interests in service education. 3. The extent of satisfaction related to psychological environments is heightend according to good physical environments. In result, the hypothesis that the extent of satisfaction in terms of physical environments could raise satisfaction about psychological environment is accepted. 4. In the light of the extent of satisfaction about physical environments, $33.3\%$ of isolated ward nurses are satisfied with physical environments, but only $11.7\%$ of general ward nurses are satisfied. $(X^2=10.88,\; p<0.01)$. This result shows that the satisfaction degree about phusicalenvironments of isolated war nurses was higher than that of general ward nurses in spite of high physical and psychological risks due to exposure to infection. Consequently. the hypothesis was rejected that the satisfaction degree about physical environments would be lower in isolated ward nurses than in general ward nurses. 5. The fact that $87.7%$ of isolated ward nurses took interest in service education and $53.19\%$ of general ward nurses took interest in service education demonstrats that isolated ward nurse have more interest in service education than gerneral ward nurses. The result shows that the hypothesis is accepted that isolated ward nurses would have mor interests in service education than general ward nurses. 6. In the extent of satisfaction about physical environments such as morale human relationship promotion, there is no significant difference between two groups in terms of statistics. The hypothesis is rejected that satisfaction about psychologic environments would be high in isolated ward nurses than in general ward nurses. In conclusion. factors influencing on job satisfaction are considered to have effect on. another, and also interdisciplinary amelioration of factors accompanied with systematic inter cooperative investigation is necessary.

• 한국산학기술학회논문지
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• 제18권3호
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• pp.312-319
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• 2017

국내 부존 청광 규조토의 고부가가치 활용을 위해 물리적인 불순물 정제 및 정제 규조토 중의 SiO2 성분을 규소원으로 한 탄화규소 분말합성에 대해 연구하였다. 청광 규조토를 hammer mill을 이용해서 분쇄한 후 체가름을 통한 입도 분리에 의해서 약 30% 정도의 철분 ($Fe_2O_3$) 정제 효과를 얻을 수 있었으며, 325 mesh 이하 입도 분말의 철분 함량은 약 2% 이었다. 습식 및 건식 자력선별의 경우 모두 철분 함량의 분리 및 정제 효과가 일부 있었지만 회수되는 비자성 부산물 중의 철분 함량이 약 2%로 잔존양이 많음을 알 수 있었다. 청광 원광의 물 침출은 철분 제거에 효과적이었으며, 물 침출 결과 약 40% 정도의 철분이 제거되었다. 또한 정제 규조토 중의 $SiO_2$ 성분을 탄소 (흑연, 카본블랙)로 환원 탄화 반응시켜 ${\beta}$-SiC를 합성하였고, 합성 분말의 산처리를 통한 철분 정제 및 비표면적 변화 등에 대해 연구하였다. 환원제로 흑연보다는 카본블랙을 사용함이 보다 효과적이었고, 산처리공정에 의해 Fe, Ca 등의 불순물들이 거의 제거되었고, 비표면적은 $52.5m^2/g$ 까지 증가하였다.

• 멤브레인
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• 제29권1호
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• pp.61-65
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• 2019

이방성 입자는 독특한 물리적 특성 때문에 다양한 분야에서 발표되고 있다. 여기서, 이방성 도토리구조 나노 입자를 제조하기 위해 새로운 동적 상분리 방법이 도입된다. 동적 상분리 방법은 용제 증발 및 무용제에 의한 침전으로 구성된다. 하부층은 비용매 희석제로서 물을 공급함으로써 제어되며, 상부층의 상분리는 휘발성 용매의 확산 및 증발에 의존한다. 이 상태에서, 도토리 형 입자가 제조되었다. 물이 채워진 밀폐된 상자(자발적 상분리)하에서, 단분산 폴리스틸렌 입자가 합성되었다. 동적 상분리와 자발적 상분리가 공존할 때, 캡과 입자의 크기가 변경되었다. 또한, 폴리스틸렌 용액의 부피는 입자 형상에 영향을 미친다. 독특한 구조가 다양한 응용 분야에 활용될 수 있기 때문에 멤브레인 기반의 제어된 물 공급과 같은 첨단 기술이 개발되면 단분산의 도토리와 같은 입자가 제조될 수 있을 것이다.

• 한국가스학회:학술대회논문집
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• 한국가스학회 1997년도 추계학술발표회 논문집
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• pp.223-228
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• 1997

• 한국자원리싸이클링학회:학술대회논문집
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• 한국자원리싸이클링학회 2005년도 추계정기총회 및 제26회 학술발표대회 고분자리싸이클링기술 특별심포지엄
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• pp.178-196
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• 2005

• 한국전문물리치료학회지
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• 제18권3호
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• pp.94-102
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• 2011

The purpose of this study was to review existing assessment tools for patients with low back pain and improve them through combination. A total of 314 patients with low back pain participated. Their condition was assessed using the Oswestry Disability Questionnaire (ODQ), the Quebec Back Pain Disability Scale (QBPD), and the Back Pain Functional Scale (BPFS). Rasch analysis was applied to identify inappropriate items, item difficulties, and the separation index. In this study, the 'sex life' item of the ODQ (10 items) and the 'sleeping' item of the BPFS (12 items) showed misfit statistics, whereas all items of the QBPD (20 items) were appropriate. After combining the ODQ, QBPD and BPFS, Rasch analysis was applied. The 'pain intensity', and the 'sex life' item of the ODQ and the 'throw a ball' item of QBPD showed misfit statistics. These 3 items were retained for further analysis. The remaining 42 combined ODQ-QBPD-BPFS items were arranged according to difficulty. For all subjects, the most difficult item was 'pain intensity', whereas the easiest was 'take food out of the refrigerator'. As the separation index of 42 combined ODQ-QBPD-BPFS was higher than that of the three questionnaires separately, difficulty of items varied with some need for rearrangement. The results of this study confirmed the possibility and need for a new back pain disability assessment tool, and produced one. Further study is needed to refine the questionnaire in consideration of psychosocial and occupational factors.