• Title/Summary/Keyword: 폐쇄효과

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Local Environments of Li in the Interlayer of Clay Minerals at Room and High Temperatures (상온 및 고온에서 점토광물 층간의 Li 환경)

  • Kim, Yeong-Kyoo;Lee, Ji-Eun
    • Journal of the Mineralogical Society of Korea
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    • v.20 no.3
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    • pp.193-201
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    • 2007
  • We used $^6Li$ and $^7Li$ MAS NMR to investigate the fate and local environments of Li in the interlayer of clay minerals such as hectorite, Woming-montmorillonite, beidellite, and lepidollite at room and high ($250^{\circ}C$) temperature. Although $^6Li$ NMR spectra show narrower peaks than those of $^7Li$ NMR, S/N ratio is low and there are no obvious differences in chemical shifts suggesting that it is difficult to apply $^6Li$ NMR to have information on the local environments of Li in the clay interlayers. $^7Li$ NMR spectra, however, show changes in the peak width and quadrupole patterns providing information on the local environments of Li in the interlayer even though changes in the chemical shift are not observed. In montmorillonite, two different local environments of Li are observed; one has a narrow peak with typical quadrupole patterns whereas another has a broad peak without those of the patterns. Changes in the peak width is also observed from broad to narrow in the $^7Li$ NMR spectra for beidellite but not for hectorite at high temperature. Our results suggest that the peak width change in the broad peak is attributed to the coordination changes in the water molecules around Li which is tightly bonded on the basal oxygen of Si tetrahedra as inner-sphere complexes. The narrow peak in montmorillnoite can be assigned to the Li bended as outer-sphere complexes.

The Changes of Respiratory Mechanics by a Bronchodilator Inhalation Under the Variable Level of PEEP in Patients with Acute Respiratory Distress Syndrome (급성호흡곤란증후군에서 기도확장제 투여 전후에 호기말양압 수준의 변화가 호흡역학에 미치는 영향)

  • Hong, Sang-Bum;Koh, Youn-Suck
    • Tuberculosis and Respiratory Diseases
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    • v.52 no.3
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    • pp.251-259
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    • 2002
  • Background : Reduced lung compliance and increased lung resistance are the primary lung mechanical abnormalities in acute respiratory distress syndrome (ARDS). Although there is little information regarding the mechanisms responsible for the increases in the respiratory resistance of ARDS, bronchodilators have been frequently administered in mechanically ventilated ARDS patients. To determine the effect of a bronchodilator on the respiratory mechanics depending on the level of applied positive end-expiratory pressure (PEEP), the changes in the respiratory mechanics by salbutamol inhalation was measured under the variable PEEP level in patients with ARDS. Materials and Methods : Fifteen mechanically ventilated paralyzed ARDS patients (14 of male, mean age 57 years) were enrolled in this study. The respiratory system compliance, and the maximum and minimum inspiratory resistance were obtained by the end-inspiratory occlusion method during constant flow inflation using the CP-100 pulmonary monitor (Bicore, Irvine, CA, USA). The measurements were performed at randomly applied 8, 10 and 12 cm $H_2O$ PEEP before and 30 mins after administrating salbutamol using a meter-dose-inhaler (100ug${\times}$6). Results : 1) The maximum inspiratory resistance of the lung was higher than the reported normal values due to an increase in the minimal inspiratory resistance & additional resistance. 2) The maximum inspiratory resistance and peak airway pressure were significantly higher at 12cm $H_2O$ of PEEP compared with those at 10cm $H_2O$ of PEEP. 3) Salbutamol induced a significant decrease in the maximum and the minimum inspiratory resistance but no significant change in the additional resistance only was observed at 12cm $H_2O$ of PEEP(from $15.66{\pm}1.99$ to $13.54{\pm}2.41$, from $10.24{\pm}2.98$ to $8.04{\pm}2.34$, and from $5.42{\pm}3.41$ to $5.50{\pm}3.58cm$ $H_2O$/L/sec, respectively). 4)The lung compliance did not change at the applied PEEP and salbutamol inhalation levels. Conclusion : The bronchodilator response would be different depending on the level of applied PEEP despite the increased respiratory resistance in patients with ARDS.

The pattern of movement and stress distribution during retraction of maxillary incisors using a 3-D finite element method (상악 전치부 후방 견인 시 이동 양상과 응력 분포에 관한 삼차원 유한요소법적 연구)

  • Chung, Ae-Jin;Kim, Un-Su;Lee, Soo-Haeng;Kang, Seong-Soo;Choi, Hee-In;Jo, Jin-Hyung;Kim, Sang-Cheol
    • The korean journal of orthodontics
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    • v.37 no.2 s.121
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    • pp.98-113
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    • 2007
  • Objective: The purpose of this study was to evaluate the displacement pattern and the stress distribution shown on a finite element model 3-D visualization of a dry human skull using CT during the retraction of upper anterior teeth. Methods: Experimental groups were differentiated into 8 groups according to corticotomy, anchorage (buccal: mini implant between the maxillary second premolar and first molar and second premolar reinforced with a mini Implant, palatal: mini implant between the maxillary first molar and second molar and mini implant on the midpalatal suture) and force application point (use of a power arm or not). Results: In cases where anterior teeth were retracted by a conventional T-loop arch wire, the anterior teeth tipped more postero-inferiorly and the posterior teeth moved slightly in a mesial direction. In cases where anterior teeth were retracted with corticotomy, the stress at the anterior bone segment was distributed widely and showed a smaller degree of tipping movement of the anterior teeth, but with a greater amount of displacement. In cases where anterior teeth were retracted from the buccal side with force applied to the mini implant placed between the maxillary second premolar and the first molar to the canine power arm, it showed that a smaller degree of tipping movement was generated than when force was applied to the second premolar reinforced with a mini implant from the canine bracket. In cases where anterior teeth were retracted from the palatal side with force applied to the mini implant on the midpalatal suture, it resulted in a greater degree of tipping movement than when force was applied to the mini implant between the maxillary first and second molars. Conclusion: The results of this study verifies the effects of corticotomies and the effects of controlling orthodontic force vectors during tooth movement.

The Clinical Effects of Surgical Treatment for Hemoptysis due to Inflammatory Lung Disease (염증성 폐질환에 의한 객혈에 대한 수술적 치료 효과)

  • Yun, Ju-Sik;Na, Kook-Joo;CheKar, Jay-Key;Jeong, In-Seok;Song, Sang-Yun;Oh, Sang-Gi
    • Journal of Chest Surgery
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    • v.43 no.2
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    • pp.144-149
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    • 2010
  • Background: Many studies have demonstrated the various therapeutic options for treating hemoptysis caused by inflammatory lung disease. However, there is debate over the surgical management of the ongoing hemoptysis. Therefore, we evaluated the clinical results of pulmonary resection that was done due to hemoptysis in patients with concomitant inflammatory lung disease. Material and Method: We performed a retrospective analysis of 75 patients who received pulmonary resection for hemoptysis and concomitant inflammatory lung disease between 2001 and 2007. The mean age was $52.1{\pm}12.5$ years old, and the male; female ratio was 52:23. Result: The underlying disease was aspergilloma in 30 patients (40%), pulmonary tuberculosis in 20 patients, bronchiectasis in 18 patients and other causes in 7 patients. The surgical treatment included lobectomy in 55 patients, bilobectony in 2 patients, pneumonectomy in 17 patients and wedge resection in 1 patient. There were 3 early deaths, and the causes of death were pneumonia in 1 patient and BPF in 2 patients. The early mortality was statistically higher for such risk factors as a preoperative Hgb level <10 g/dL, COPD and an emergency operation. Conclusion: In conclusion, pulmonary resection for treating hemoptysis showed the acceptable range of mortality and it was an effective method for the management of hemoptysis in patients with inflammatory lung disease. However, relatively high rates of mortality and morbidity were noted for an emergency operation, and so meticulous care is needed in this situation.

Standards of Protection in Investment Arbitration for Upcoming Climate Change Cases (기후변화 관련 사건에 적용되는 국제투자중재의 투자자 보호 기준)

  • Kim, Dae-Jung
    • Journal of Arbitration Studies
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    • v.24 no.2
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    • pp.33-52
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    • 2014
  • Although climate change is a global scale question, some concerns have been raised that principles of investment arbitration may not adequately address the domestic implementation of climate change measures. A recent ICSID investment arbitration of Vattenfall v. Germany with regard to the investor's alleged damages from the phase-out of nuclear plants is a salient climate change case. The 2005 Kyoto Protocol was made to reduce greenhouse gas emissions and it provides a number of flexible mechanisms such as Joint Implementation (JI) and Clean Development Mechanism (CDM). Implementation of the Kyoto Protocol allows dispute settlement through investor-state arbitration. Any initiation of stricter emission standards can violate the prohibition on expropriations in investment agreements, regardless of the measures created to reduce greenhouse gas emissions. The effect-based expropriation doctrine can charge changes to existing emission standards as interference with the use of property that goes against the legitimate expectation of a foreign investor. In regulatory chill, threat of investor claims against the host state may preclude the strengthening of climate change measures. Stabilization clauses also have a freezing effect on the hosting state's regulation and a new law applicable to the investment. In the fair and equitable standard, basic expectations of investors when entering into earlier carbon-intensive operations can be affected by a regulation seeking to change into a low-carbon approach. As seen in the Methanex tribunal, a non-discriminatory and public purpose of environmental protection measures should be considered as non-expropriation in the arbitral tribunal unless its decision would intentionally impede a foreign investor's investment.

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Effects of Cortisol on the Steroidogenesis and the Apoptosis of Human Granulosa-Lutein Cells (Cortisol이 사람 과립-황체화 세포의 스테로이드 생성과 세포자연사에 미치는 영향)

  • Kim, Jin-Hee;Yang, Hyun-Won
    • Development and Reproduction
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    • v.13 no.4
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    • pp.329-339
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    • 2009
  • Cortisol is present in high concentration in the ovary and its receptor is expressed in the ovarian cells. Moreover, cortisol is known to have a role in steroid synthesis and cell metabolism in human granulosa and lutein cells. However, little is known of the role of cortisol presenting in high concentration in the follicles after LH surge on the granulosa-lutein cells. Therefore, the this study we evaluated the apoptosis and the production of progesterone $(P_4)$ and estradiol $(E_2)$ in the granulosa-lutein cells that are obtained during oocyte-retrieval after treatment with 5, 50, and $500{\mu}g/m\ell$ cortisol and 1 IU/$m\ell$ FSH. Results of DNA fragment analysis and TUNEL assay demonstrated that DNA fragmentation and the rate of apoptotic cells were increased in a dose-dependent manner showing a significant increase in 50 and $500{\mu}g/m\ell$ cortisol treated cells. We found, however, that FSH did not suppress the apoptosis of the cells induced by cortisol. In the results of chemiluminescence assay for $P_4$ and $E_2$, $P_4$ production was decreased by cortisol treatment, whereas $E_2$ was not changed. We also demonstrated that FSH did not inhibit the suppressive effect of GnRH on $P_4$ production as the result of apoptosis. The present study suggests that cortisol of high concentration could cause the apoptosis of human granulosa-lutein cells by suppressing the production of $P_4$. However, we need more studies to elucidate the mechanism by which cortisol induces apoptosis in human granulosa-lutein cells in view of the fact that our results are inconsistent with previous reported data.

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Chemical Mass Balance of Materials in the Keum River Estuary: 1. Seasonal Distribution of Nutrients (금강하구의 물질수지: 1. 영양염의 계절적 분포)

  • Yang, Jae-Sam;Jeong, Ju-Young;Heo, Jin-Young;Lee, Sang-Ho;Choi, Jin-Yong
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.4 no.1
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    • pp.71-79
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    • 1999
  • As part of an on-going project investigating flux of materials in the Keum River Estuary, we have monitored seasonal variations of nutrients, suspended particulate matter (SPM), chlorophyll, and salinity since 1997. Meteorological data and freshwater discharge from the Keum River Dike were also used, Our goal was to answers for (1) what is the main factor for the seasonal fluctuation of nutrients in the Keum River Estuary? and (2) are there any differences in nutrient distributions before and after the Keum River Dike construction? Nitrate concentrations in the Keum River water were kept constant through the year. Whereas other nutrients varied with evident seasonality: high phosphate and ammonium concentrations during the dry season and enhanced silicate contents during the rainy season. SPM was found similar trend with silicate. During the rainy season, the freshwater discharged from the Keum River Dike seemed to dilute the phosphate and ammonium, but to elevate SPM concentration in the Keum Estuary. In addition, the corresponding variations of SPM contents in the estuarine water affected the seasonal fluctuations of nutrients in the Estuary. The most important source of the nutrients in the estuarine water is the fluvial water. Therefore, the distribution patterns of nutrients in the Estuary are conservative against salinity. Nitrate, nitrite and silicate are conservative through the year. The distribution of phosphate and ammonium on the other hand, display two distinct seasonal patterns: conservative behavior during the dry season and some additive processes during the rainy days. Mass destruction of freshwater phytoplankton in the riverine water is believed to be a major additive source of phosphate in the upper Estuary. Desorption processes of phosphate and ammonium from SPM and organic matter probably contribute extra source of addition. Benthic flux of phosphate and ammonium from the sediment into overlying estuarine water can not be excluded as another source. After the Keum River Dike construction, the concentrations of SPM decreased markedly and their role in controlling of nutrient concentrations in the Estuary has probably diminished. We found low salinity (5~15 psu) within 1 km away from the Dike during the dry season. Therefore we conclude that the only limited area of inner estuary function as a real estuary and the rest part rather be like a bay during the dry season. However, during the rainy season, the entire estuary as the mixing place of freshwater and seawater. Compared to the environmental conditions of the Estuary before the Dike construction, tidal current velocity and turbidity are decreased, but nutrient concentrations and chance of massive algal bloom such as red tide outbreak markedly increased.

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Applicability of Vegetation Index and SPAD Reading to Nondestructive Diagnosis of Rice Growth and Nitrogen Nutrition Status (식생지수와 SPAD를 이용한 벼 생육 및 질소영양상태의 비파괴적 진단 가능성 검토)

  • Kim Min-Ho;Shin Jin-Chul;Lee Byun-Woo
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.50 no.6
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    • pp.369-377
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    • 2005
  • Precise application of topdressing nitrogen (N) fertilizer is indispensible for securing high yield and good quality of rice and minimizing N losses to the environment as well. For precise N management, growth and nitrogen nutrition status (NNS) should be diagnosed rapidly and accurately. The objective of the study was to evaluate the applicability of vegetation index (VI) calculated from hyperspectral canopy reflectance measurement and SPAD reading to nondestructive in situ diagnosis of growth and NNS of rice. Canopy reflectance, SPAD read­ing, growth parameters, and NNS characteristics were measured from various N treatments to evaluate the relationships among them for two cropping seasons from 2001 to 2002. The correlation coefficient of VIs with variables of growth and NNS increased positively as rice canopy became more closed. Regardless of growth stages, VIs had significantly high correlations with LAI, shoot dry weight (DW), shoot N content and nitrogen nutrition index (NNI). Those correlation coefficients increased steadily before heading stage as rice grew up. However, tiller number and leaf N concentration showed significantly high correlations with VIs only at and after panicle initiation stage (PIS). Among the VIs, RVIgreen had significantly higher correlation with the measured parameters than the other VIs: it showed correlation coefficients greater than 0.8 with leaf and shoot N concentration and DW, and much higher coefficients greater than 0.9 with LAI, shoot N content, and NNI. At LAI of below 2.5, VIs had non-significant or low correlations with the growth and NNS indicators due to the background effects. SPAD reading had significantly high correlation with leaf N concentration and NNI at each growth stage. In addition, it had significant correlations with variables of growth and NNS at PIS and booting stage, particularly, at booting stage. Though SPAD reading had a significantly high correlation value at a given growth stage in each year, it showed very weak relationship with variables of growth and NNS when pooled across growth stages and years. In conclusion, RVIgreen was found to be the most reliable VI to estimate the growth and NNS of rice around at PIS, but SPAD reading had much limitations.

Water Quality and Hydrochemistry of Natural Springs and Community Wells in Daejeon Area (대전지역 자연샘물 및 공동우물의 수질 및 수리화학적 특성)

  • 정찬호;박충화;이광식
    • Economic and Environmental Geology
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    • v.35 no.5
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    • pp.395-406
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    • 2002
  • The sixty natural springs and community wells used as a drinking water in the Daejeon area are mainly located at the parks and the natural green districts. The purpose of this study is to investigate the characteristics of water quality and the contamination of the springs and the wells, and to suggest the management strategy for the springs and wells. For this study, we undertook water quality data from Daejeon City. According to the statistic analysis of water quality data, unacceptable rate as a drinking water was about 28 percent in 1999 and 24.5 percent in 2000, respectively. Major unacceptable factor is coliform, and others are bacteria, yersinia, color, turbidity, Fe and F. The unacceptable rate shows a roughly positive relationship with precipitation, that is, it shows highest rate during a rainy season between June and September. The major contamination source is likely to be the excrement of wild animals around natural springs and wells. Most of springs are vulnerable to the contamination of coliform and bacteria because of short residence time and shallow circulation in subsurface environment. The water samples collected from 31 springs or wells show weak acidic pHs, the electrical conductivity ranging from 63 to 357 $\mu\textrm{S}$/cm, and the hydrochemical types of Na(Ca)-HC0$_3$ and Ca-HC0$_3$. The groundwater samples of low total dissolved solid(TDS) belong to Na(Ca)-HC0$_3$. type, and the groundwater of high total dissolved solid is shifted towards Ca-HC0$_3$ type in the chemical composition. These hydrochemical characteristics indicate that most natural springs is in the early stage of geochemical evolution. The natural springs should be closed during a rainy season, which shows a high contamination rate. We suggest that a protection barrier around the springs should be built to keep wild animals away from the springs.

Extraction and Quality Stability of Products Containing Lilium Bulb and Lespedeza cuneata G. Don Extracts (백합과 비수리의 추출 및 추출혼합물이 함유된 음료 제품의 품질 안정성)

  • Kim, Seung Tae;Heo, Chang Hoe;Kim, Sung Hoon;Lee, Won Jong
    • Journal of Food Hygiene and Safety
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    • v.35 no.1
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    • pp.75-82
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    • 2020
  • The purpose of this study was to establish optimized extraction conditions for Lilium bulb and Lespedeza cuneata G. Don and to investigate the storage stability of beverages containing extracts. The hot-water extract and the 60% ethanol extract had the highest DPPH radical scavenging activities as well as the highest total polyphenol content. The total polyphenol content, total flavonoid content and DPPH radical scavenging activity were the highest when the Lilium bulb extract was mixed with the Lespedeza cuneata G. Don extract at the ratio of 1:4. Storage stability of beverages was determined during storage at 10, 25, and 35℃ for 6 months. The pH was decreased from 4.15 to 4.01-4.05, while the acidity was increased from 0.60% to 0.70-0.75% after storage for 6 months. The soluble solid contents were not changed during storage of 6 months. The DPPH radical scavenging activity was decreased after 4-6 months. The Hunter b (yellowness) values decreased at 35℃ after storage for 6 months while the lightness (L) and redness (a) were not changed during storage for 6 months. The total saponin content was not remarkably changed during 2 months of storage, while it decreased after 4-6 months of storage. The flavonoid content was decreased 47% and 55% from an intial 21.7 mg/100 mL to 10.3 mg/100 mL and 12.0 mg/100 mL after 1 month of storage and then remained stable until 6 months. General bacteria and coliform group were not detected during storage for 6 months.