• Journal of Nutrition and Health
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• v.49 no.1
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• pp.18-27
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• 2016

Purpose: Our previous study demonstrated the hypoglycemic effects of mulberry (Morus alba L.) leaf and the underlying mechanisms. Here we explored the potency of mulberry twigs (TW) and root barks (RB) in postprandial hypoglycemic effects in vitro and in vivo. Methods: The major components of TW and RB were determined by high performance liquid chromatography (HPLC). Alpha-glucosidase inhibition and glucose/fructose uptake inhibition in Caco-2 cells were determined for TW, RB, and their major components, followed by an oral sugar tolerance test (OSTT) in streptozotocin-induced diabetic rats. Male Wistar rats were fed a high-fat diet for 2 weeks and then a single dose of streptozotocin (35 mg/kg B.W) was administered by intraperitoneal injection. Rats with fasting blood glucose levels above 126 mg/dL were randomly divided into 5 groups (n = 8/group) for the following treatments by gavage for 4 weeks: vehicle (normal control and diabetic control), 200 mg/kg B.W of TW or RB or 100 mg/kg B.W of oxyresveratrol (OXY). Results: OXY and mulberroside A were identified as the major components of TW and OXY, mongolicin, and kuwanon H for RB. A significant inhibitory activity on ${\alpha}-glucosidase$ was found for TW, RB, and OXY (p = 0.0099). There was a dose-dependent inhibition of TW and RB on the intestinal sugar uptakes in Caco-2 cells, showing a greater impact on fructose compared to glucose. The OSTT showed that TW and RB significantly delayed time to maximal concentration (p = 0.0088) and decreased maximal concentration (p = 0.0043) compared to the control group. Conclusion: These results suggest that TW and RB may have a postprandial hypoglycemic effect, particularly in the case of high fructose or sucrose intake. OXY was suggested as a contributor to the hypoglycemic effect of TW and RB. Further studies are needed for the systemic effect of TW and RB in circulation.

• Journal of Chest Surgery
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• v.31 no.12
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• pp.1147-1158
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• 1998

Background: Portable cardiopulmonary bypass(CPB) technique has been used increasingly as a potent and effective option for emergency cardiopulmonary resuscitation(CPR) because it can maintain more stable hemodynamics and provide better survival than conventional CPR techniques. This study was designed to develop a prototype of Korean portable CPB system and, by applying it to CPR, to discriminate whether it would be superior to standard open-chest CPR. Material and Method: By using adult mongrel dogs, open-chest CPR(OCPR group, n=4) and portable-CPB CPR(CPB group, n=4) were compared with respects to restoration of spontaneous circulation(ROSC), hemodynamics, effects on blood cells, blood gas patterns, biochemical markers, and survivals. Ventricular fibrillation-cardiac arrest(VF-CA) of arrest(VF-CA) of 4 minutes followed by basic life support(BLS) of 15 minutes was applied in either group, which was standardized by the protocol of American Heart Association. Then, advanced life support(ALS) was applied to either group under the support of internal cardiac massage or CPB. ALS was maintained until ROSC was achieved but not longer than 30 minutes regardless of the presence of ROSC. All of the measured values were expressed as means±SD percent change from baseline. Result: During the early ALS, higher mean arterial pressure was maintained in CPB group than in OCPR group(90±19 vs. 71±32 %; p<.05) and lower mean pulmonary arterial pressure was also maintained in CPB group than in OCPR group(105±24 vs. 146±6%; p<.05). ROSC was achieved in all dogs. Post-ROSC levels of hematocrit, RBC, and platelet were decreased and plasma free hemoglobin was increased significantly in CPB group compared to OCPR group(p<.05). Changes in blood gas patterns, lactate, and CK-MB levels were not different between groups. Early mortality was seen in 3 dogs in OCPR group(survival time 31±36 hours) and 2 in CPB group(228±153 hours, p=ns). The remainders in both groups showed prolonged survival. Conclusion: These findings indicate that portable CPB can be effective to maintain stable hemodynamics during cardiac arrest, to achieve ROSC and to prolong survival. Further study is needed to refine the portable CPB system and to meet clinical challenges.

• Korean Chemical Engineering Research
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• v.58 no.2
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• pp.235-247
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• 2020

Simulation study and validation on 50 L/hr pilot-scale Bunsen process was carried out in order to investigate thermodynamics parameters, suitable reactor type, separator configuration, and the optimal conditions of reactors and separation. Sulfur-Iodine is thermochemical process using iodine and sulfur compounds for producing hydrogen from decomposition of water as net reaction. Understanding in phase separation and reaction of Bunsen Process is crucial since Bunsen Process acts as an intermediate process among three reactions. Electrolyte Non-Random Two-Liquid model is implemented in simulation as thermodynamic model. The simulation results are validated with the thermodynamic parameters and the 50 L/hr pilot-scale experimental data. The SO₂ conversions of PFR and CSTR were compared as varying the temperature and reactor volume in order to investigate suitable type of reactor. Impurities in H₂SO₄ phase and HI_X phase were investigated for 3-phase separator (vapor-liquid-liquid) and two 2-phase separators (vapor-liquid & liquid-liquid) in order to select separation configuration with better performance. The process optimization on reactor and phase separator is carried out to find the operating conditions and feed conditions that can reach the maximum SO₂ conversion and the minimum H₂SO₄ impurities in HI_X phase. For reactor optimization, the maximum 98% SO₂ conversion was obtained with fixed iodine and water inlet flow rate when the diameter and length of PFR reactor are 0.20 m and 7.6m. Inlet water and iodine flow rate is reduced by 17% and 22% to reach the maximum 10% SO₂ conversion with fixed temperature and PFR size (diameter: 3/8", length:3 m). When temperature (121℃) and PFR size (diameter: 0.2, length:7.6 m) are applied to the feed composition optimization, inlet water and iodine flow rate is reduced by 17% and 22% to reach the maximum 10% SO₂ conversion.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.2
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• pp.178-184
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• 1992

The changes in contents of chlorophyll and free proline in the seedling leaves of ten rice cultivars as affected by salt stress were checked in order to obtain the basic information on the judgement of the degrees of salt injury. The difference in salt injury among the cultivars was clearly observed about 25 days after 6% salt treatment. Chlorophyll content was decreased in both Gayabyeo and Taebaegbyeo for 14 days after different salt treatment as salt concentration was increased and the decreased tendency was much higher in Taebaegbyeo than in Gayabyeo over 0.4% salt concentration. Chlorophyll content in Gayabyeo after 0.6% salt treatment was decreased slowly, while in Taebaegbyeo, deminished very rapidly as time progressed, therefore it decreased by about 16% in Gayabyeo and 67% in Taebaebyeo compared to the control at 20 days, respectively. The relationship between chlorophyll content and the degrees of salt injury in ten rice cultivars showed significant negative correlation at 10 day after 0.6% salt treatment. Free proline content in Gayabyeo was increased gradually for 14 days after different salt treatment as salt became higher, while in Taebaebyeo, it was increased rapidly under 0.6% but rather decreased under 0.8% salt concentration. Particularly, it was much higher Taebaegbyeo than in Gayabyeo under salt concentration from 0.4 to 0.6%. Free proline content in Gayabyeo after 0.6% salt treatment was increased from 15 days, on the other hand in Taebaegbyeo, it was increased from 5 days, but rather decreased from 20 days, and it was 6 times higher in Taebaegbyeo than in Gayabyeo at 10 days. There was significant positive correlation between free proline content and the degrees of salt injury in ten rice cultivars at 10 days after 0.6% salt treatment. From the above results, chlorophyll and free proline content may be used as an indicative character of intensity of salt stress as well as varietal difference in resistance to salt stress in the seedling stage.

• 한국지구과학회:학술대회논문집
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• 2010.04a
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• pp.108-109
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• 2010

IMPACT Silver 주식회사는 Zacualpan 프로젝트의 Royal Mines(이하 로얄 광산)을 인수했다. $124.5\;km^2$에 해당하는 지역의 소유권은 두 개의 멕시코 사기업으로부터 가행중인 광산의 채굴권 구입과 운영 중인 기반시설의 임대를 조건으로 한다. 프로젝트 지역은 멕시코시티로부터 남서방향으로 100 km와 Taxco Silver 광산으로부터 북서방향으로 25 km 떨어진 지점에 위치한다. 기반시설은 비포장 도로, 충분한 전력과 물의 공급 및 숙련공들을 갖추어 우수한 평가를 받고 있다. 소유권은 멕시코인의 개인소유 하에서 무한한 매장량 혹은 자원량을 갖고 운영된 채광과 가공시설을 인수하는 것이다. 소유권 지역을 대상으로 한 IMPACT Silver사의 주 탐사목적은 이미 알려진 광화대의 확장을 위한 잠재성 평가와 다른 지역에서 신규 광상의 유망지역을 발견하는 것이다. Zacualpan 프로젝트의 로얄 광산은 남동 Guerrero terrane의 북부에 위치한다. Teloloapan subterrane은 주로 저변성 녹색편암상으로 구성된 쥬라기 후기에서 백악기 초기의 화산성 퇴적층으로 구성된다. 대부분의 유망지역은 Lower Villa de Ayala층의 중성 내지 염기성 화산성 쇄설암을 모암으로 한다. 다상의 변성작용은 지역 전반에 걸쳐 나타나고, Zacualpan 광산지역에서 수반되는 광화작용을 규제한다. Zacualpan 광산지역은 Sierra Madre del Sur로 알려진 유망 광화대에 해당한다. 이 지역은 화산성 괴상 황화광상과 천열수 맥상광상이 우세하다. 대부분의 천열수 광화작용은 3.2-3.8억 년 전 마그마의 생성이 활발한 판구조 체제 동안 발생하였다. 역사적으로 가장 주요한 지역은 Lipton Vein이다. 현재 Zacualpan 지구에서 채광량은 은 200-500 g/t 정도로 보고되고 있다. 일부 지역은 고품위 은 광화작용(은 1,000 g/t 이상)을 수반하고 있으며, 이는 탐사의 주 타겟이 되고 있다. Zacualpan에서 은 광화작용은 은이 부화된 중유황 천열수 맥상광상으로 상당히 유명하다. Fresnillo, Pachuca 및 Taxco 광산을 포함한 멕시코 소유의 대규모의 잘 알려진 광산들이 이에 해당한다. 이러한 광산들은 부산물로서 금, 아연, 연이 생산된다. 이러한 광상들은 맥상과 각력상 및 산점상 또는 망상세맥의 형태로 산출된다. 광화작용은 석영과 탄산염 맥 내에 주로 황철석과 다양한 섬아연석, 방연석, 은 혹은 금 광물들을 수반한다. 경제성을 갖는 광화작용의 수직적인 연장은 평균적으로 대략 300 m이고, 멕시코 중부에 위치한 Fresnillo의 광화작용은 100 m에서 960 m의 연장을 갖는 것으로 알려져 있다. 아주 오랫동안 Zacualpan에서 광산관계자의 관측과 IMPACT Silver에서 최근 작업의 결과를 토대로, Zacualpan 광산지역의 탐사모델은 새로운 광상의 탐사를 위한 가이드로서 개발되었다. Zacualpan 광산지역에서 가장 높은 경제성을 갖는 광화작용은 북서와 남북방향의 맥 구조를 따라 수반된다. 이러한 맥 구조들은 종종 이 지역을 가로질러 수 km까지 추적되지만, 경제성을 갖는 광화작용은 맥 구조를 따라서 구조적으로 유리한 지역에서 부광대를 형성한다. 부광대를 형성하기 위한 가장 유리한 구조적 지역은 북서와 남북방향으로 발달한 맥 구조들이 교차하는 지역이다. 지난 30년간 채광된 주요 부광대는 폭이 2-6 m 이고 수평연장은 30-150 m 그리고 수직연장은 230-300 m에 이른다. 가장 높은 생산량을 보이는 부광대는 남북방향의 이차 맥들이 Guadalupe 광산의 Lipton 맥을 가로지르는 지역에서 발달한다. 남동쪽으로 현재 Compadres 광산의 Silver Shoot No. 1으로부터 고품위 은을 생산하는 지역은 북서방향의 San Agustin 맥이 북향의 Cometa Navideno 맥에 의해 절단되는 지역에서 산출한다. 모암은 광화작용을 규제하는 또 다른 중요한 요소이다. 광산지역에서 경제성을 갖는 모든 광화작용은 중성 내지 염기성 화산암 특히 안산암과 관련 모암에 배태된다. 부광대가 셰일 혹은 편암으로 전이되는 지역에서, 맥들은 소규모의 세맥으로 나뉘어 진다. Zacualpan의 전형적인 천열수 광상에서 부광대는 상부로 가면서 은의 함량이 증가하고, 하부로 가면서 연 아연의 함량이 증가하는 수직적 대상을 보인다. 금의 함량 변화는 보다 예측이 어려우나 상당히 중요하다. Zacualpan 광산지역의 탐사모델에 사용된 토양 채취, 정밀지도제작, 트렌치 및 시추탐광은 현재 IMPACT Silver사가 이 지역을 대상으로 한 가장 효율적인 탐사방법으로 입증되었다. Zacualpan 프로젝트의 로얄 광산은 하루 500 톤을 제련하는 기반시설과 수반된 채굴권을 갖는 가행 광산들을 포함한다. 현재 IMPACT Silver사는 두 곳의 타겟 지역에서 정밀지도제작, 토양 및 암석 채취, 12공 총 1866 m의 시추탐광에 의한 사전조사로 구성된 4 단계 탐사를 수행했다. 암석 1,953개, 토양 1,631 개, 389 개의 시추코어 시료가 채집되고 분석되었다. 이러한 작업은 추가탐사를 요구하는 수많은 유망 광화대를 규명했다. Compadres 광산에서 현재 가행중인 지하갱 시료는 레벨 1에서 0.9 m의 폭을 갖는 광체에서 은 680 g/t과 금 0.3 g/t, 레벨 3에서 1.67 m의 폭을 갖는 광체에서 은 12,591 g/t과 금 12.07 g/t의 품위를 갖는 것으로 나타났다. 레벨 1에서 3까지 2-3 m의 폭과 30-40 m 연장으로 채광되었다. 시추탐광은 고품위를 갖는 몇몇의 중첩된 맥을 발견했다. Compadres 광산에서 남동방향으로 200 m지점에 위치한 Soledad 지역에서 5 개의 시추공으로부터 동일 맥 시스템이 발견되었고, 고품위 부광대의 상부로 간주되는 몇몇 중요 지점이 발견되었다. 초기 단계의 탐사는 유망 시추탐광 지역인 중간정도 내지 고품위 유망 광화대를 규명했다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.1
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• pp.81-91
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• 2010

IMO(International Maritime Organization) and the Shipping World rave complied with various kinds of international regulations for maritime safety and marine environmental protection, but the main reason of maritime accidents is that developing countries cannot implement maritime safety related regulations. Although Korea has been a member of the "A group" council of IMO, maritime technology transfer records of Korea are not good. To promote the project of official development assistance in Korea, it is required to select the technology which has a high degree of importance in the fields of maritime safety and has a high degree of demand on the transfer to developing countries, and to concentrate on the selected technology. So, it is necessary to draw valuation factors for maritime safety technology and to decide the priority in order among maritime safety technologies on the basis of valuation factors. Because the weights which show the degree of importance among valuation factors are different from factor to factor, interdependent relationship between factors should be considered on evaluation. In this study, the valuation factors were divided into three groups as the maturity of maritime safety technology, the promotion probability of projects and the degree of importance of technology, and the detailed factors of each group were drawn. A model which used Fuzzy AHP and limiting probability to consider the weights of importance and correlation among valuation factors was developed. To adopt this model, nine types of maritime safety technology in the field of maritime safety information were selected and points were scored for each technology through evaluation. In conclusion, first, ENC related technology was scored to be the highest as 0.0139. Second, the point of ship monitoring technology was scored as 0.0133. Last, oil spill response technology was scored as 0.0132.

• Korean Journal of Heritage: History & Science
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• v.48 no.3
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• pp.80-95
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• 2015

The purpose of this study is to establish an effective protection and management system for World Heritage (WH) nomination of Southwestern Coast Tidal Flat (SCTF) by proposing a model of protection and management. SCTF has a potential to become a representative best practice to achieve a sustainable development for human society. SCTF has a potential Outstanding Universal Values (OUVs) for WH nomination, thus a harmony between human and nature for wise use of natural resources needs to be pursued. It is required to present the system of SCTF's protection and management and to analyze present status of the regions in the Tentative List by comparing the case which were already inscribed as WH. For better protection of nominated areas, SCTF should expand an area for protection with additional designation. For the management system, two separate management systems such as the Department of Culture & Tourism and the Department of Oceans & Fisheries need to be reconciled. Because of this overlapping management structure, the management of the nominated sites has been inefficient and long-term management plan is lacking. Therefore, it is necessary to integrate conflicting management system of each local government and make a long-term, integrated management plan. To make an efficient and sustainable protection and management, it is essential to set up a collaboration system by integrating various stakeholders such as central and local governments, academic organizations, local residents, and NGOs. As in the case of Wadden Sea, the combined community system of the stakeholders mentioned above should be established. Because it is essential for local residents to understand a basic concepts for protection and management, it is necessary to establish capacity-building of local people. The protection and management structure should be set up by bottom-up processes, that is the proper structure shoud be based on thorough research on local society as well as thorough communication with local residents to make relevant laws and policies. This study also propose the proper plan for better conservation and management of SCTF.

• Journal of Korean Society of Forest Science
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• v.109 no.4
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• pp.477-483
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• 2020

We constructed a stand yield table for Chamaecyparis obtusa based on data from an actual forest. The previous stand yield table had a number of disadvantages because it was based on actual forest information. In the present study we used data from more than 200 sampling plots in a stand of Chamaecyparis obtusa. The analysis included theestimation, recovery and prediction of the distribution of values for diameter at breast height (DBH), and the result is a valuable process for the preparation ofstand yield tables. The DBH distribution model uses a Weibull function, and the site index (base age: 30 years), the standard for assessing forest productivity, was derived using the Chapman-Richards formula. Several estimation formulas for the preparation of the stand yield table were considered for the fitness index, and the optimal formula was chosen. The analysis shows that the site index is in the range of 10 to 18 in the Chamaecyparis obtusa stand. The estimated stand volume of each sample plot was found to have an accuracy of 62%. According to the residuals analysis, the stands showed even distribution around zero, which indicates that the results are useful in the field. Comparing the table constructed in this study to the existing stand yield table, we found that our table yielded comparatively higher values for growth. This is probably because the existing analysis data used a small amount of research data that did not properly reflect. We hope that the stand yield table of Chamaecyparis obtusa, a representative species of southern regions, will be widely used for forest management. As these forests stabilize and growth progresses, we plan to construct an additional yield table applicable to the production of developed stands.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.2
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• pp.193-215
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• 2022

Recently, ground structures have reached saturation, and underground construction using underground structures such as tunnels has been in the spotlight as a way to solve increasing traffic difficulties and environmental problems. However, due to the increasing number of underground structures, close construction is inevitable for continuous underground development. When a new underground structure is constructed closely, stability may become weak due to the influence on the existing tunnel, which may cause collapse. Therefore, analyzing the stability of existing tunnels due to new structures is an essential consideration. In this study, the effect of excavating new tunnels under parallel tunnels on existing parallel tunnels was analyzed using numerical analysis. Using the Displacement Control Model (DCM), the volume loss generated during construction was simulated into three case (0.5%, 1.0%, and 1.5%). Based on the center of the pillar, the distance where the new tunnel is located was set to 5 m, 6 m, 7 m, 8 m, 9 m, and the space for each distance were set to 5 (0D₁, 0.37D₁, 0.75D₁, 1.13D₁, 1.5D₁). In general, as the volume loss increased and the distance approached, the maximum displacement and angular displacement increased, and the strength/stress ratio to evaluate the stability of the pillar also decreased. As a result, when the distance between the new tunnel and the center of the pillar is 5 m, the space is 0D₁, and the volume loss is 1.5%, the stability of the existing parallel tunnel is the weakest.

• Korean Journal of Remote Sensing
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• v.39 no.6_1
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• pp.1341-1352
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• 2023

The normalized difference vegetation index (NDVI) derived from satellite images is a crucial tool to monitor forests and agriculture for broad areas because the periodic acquisition of the data is ensured. However, optical sensor-based vegetation indices(VI) are not accessible in some areas covered by clouds. This paper presented a synthetic aperture radar (SAR) based approach to retrieval of the optical sensor-based NDVI using machine learning. SAR system can observe the land surface day and night in all weather conditions. Radar vegetation indices (RVI) from the Sentinel-1 vertical-vertical (VV) and vertical-horizontal (VH) polarizations, surface elevation, and air temperature are used as the input features for an automated machine learning (AutoML) model to conduct the gap-filling of the Sentinel-2 NDVI. The mean bias error (MAE) was 7.214E-05, and the correlation coefficient (CC) was 0.878, demonstrating the feasibility of the proposed method. This approach can be applied to gap-free nationwide NDVI construction using Sentinel-1 and Sentinel-2 images for environmental monitoring and resource management.