• Title/Summary/Keyword: Cold region

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Dynamic Soil Properties of Frozen and Unfrozen Soils from Terra Nova Bay in Eastern Antarctica (동남극 테라노바만 흙 시료의 동결 및 비동결 상태에서의 동적특성 평가)

  • Kim, Jae-Hyun;Kwon, Yeong-Man;Park, Keunbo;Kim, YoungSeok;Kim, Dong-Soo
    • Journal of the Korean Geotechnical Society
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    • v.33 no.3
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    • pp.37-47
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    • 2017
  • The geotechnical characteristics of frozen ground is one of the key design issues for the construction of infrastructure in cold region. In this study, the dynamic properties (shear modulus and damping ratio) of frozen and unfrozen soils sampled from Terra Nova Bay located in eastern Antarctica, where Jang Bogo station was built, were investigated using Stokoe-type resonant column test (RC). In order to freeze the reconstituted soil specimen, the RC testing equipment was modified by adding a cooling system. A series of resonant column tests were performed in frozen and unfrozen soils with various soil densities and temperatures. The shear modulus (G) and damping ratio (D) of soil frozen at $-7^{\circ}C$ were compared with those of unfrozen soil. In addition, the effect of temperature rise on the maximum shear modulus ($G_{max}$) and damping ratio was experimentally investigated. This study has significance in that the difference of dynamic soil properties between frozen and unfrozen soils and the effect of temperature rise on frozen soil were identified.

A Study on Concrete Curing Quality Management Based on Various Test of Construction Condition under Hot Weather Circumstance (서중(暑中) 환경에서 현장 콘크리트 시험을 통한 양생 품질관리 방안)

  • Park, Shin
    • Korean Journal of Construction Engineering and Management
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    • v.7 no.2 s.30
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    • pp.71-80
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    • 2006
  • It is required to study systematical on the concrete quality management to extend structure life because rebuilding effect is reducing under present condition of large sized and high stories structure. Concrete, which shows its intensity by hydrating action and a big change in quality according to hot weather and temperature, produces a lot of quality problem under hot and cold weather. Because of each specification and construction plan which does not have basic standard on site, concrete's quality is irregular and makes some defect. As a result, Dae-gu is fumed out to be the longest area after investigating application period and days focused on 8 cities weather information about t relationship between hot weather circumstance and construction environment. Therefore, we first surveyed the curing construction processing in the region and found out the problem of quality management. Then figure out the way of solution. Moreover, we integrated curing quality management, which is applied differently to each site, to have equal quality and to reduce defect from construction site. And then, based on various test of construction condition and analysis of quality management item, we suggest effective concrete quality management to make curing construction standard guide and plan under hot weather.

Synoptic Climatic Patterns for Winter Extreme Low Temperature Events in the Republic of Korea (우리나라 겨울철 극한저온현상 발생 시 종관 기후 패턴)

  • Choi, Gwangyong;Kim, Junsu
    • Journal of the Korean Geographical Society
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    • v.50 no.1
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    • pp.1-21
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    • 2015
  • The present study aims to characterize the synoptic climatic patterns of winter extreme low temperature events occurred in different regions of Korea based on daily temperature data observed at 61 weather stations under the supervision of the Korea Meteorological Administation and NCEP/NCAR reanalysis I data for the recent 40 years (1973~2012) period. Analyses of daily maximum and minimum temperatures below 10th percentile thresholds show that high frequencies of winter extreme low temperature events appear across the entire regions of Korea or in either the western or eastern half region divided by major mountain ridges at the 2~7 dayintervals particularly in the first half of the winter period (before mid-January). Composite analyses of surface synoptic climatic data including sea level pressure and wind vector reveal that 13 regional types of winter extreme low temperature events in Korea are closely associated with the relative location and intensity of both the Siberian high pressure and the Aleutian low pressure systems as well as major mountain ridges. Investigations of mid-troposphere (500 hPa) synoptic climatic charts demonstrate that the blocking-like upper troposphere low pressure system advecting the cold air from the Arctic toward the Korean Peninsula may provide favorable synoptic conditions for the outbreaks of winter extreme low temperature events in Korea. These results indicate that the monitoring of synoptic scale climatic systems in East Asia including the Siberian high pressure system, the Aleutian low pressure system and upper level blocking system is critical to the improvement of the predictability of winter extreme low temperature events in Korea.

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Prenatal diagnosis of the spinal muscular atrophy type I using genetic information from archival slides and paraffin-embedded tissues

  • Choi, Soo-Kyung;Cho, Eun-Hee;Kim, Jin-Woo;Park, So-Yeon;Kim, Young-Mi;Ryu, Hyun-Mee;Kang, Inn-Soo;Jun, Jung-Young;Chi, Je-G.
    • Journal of Genetic Medicine
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    • v.2 no.2
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    • pp.53-57
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    • 1998
  • Spinal muscular atrophy (SMA) type I is a common severe autosomal recessive inherited neuromuscular disorder that has been mapped to chromosome 5q11.2-13.3. The survival motor neuron (SMN) gene, a candidate gene, is known to be deleted in 96% of patients with SMA type I. Presently, PCR and single strand conformation polymorphism (PCR-SSCP) analyses have been made possible for application to both archival slides and paraffin-embedded tissues. Archival materials represent valuable DNA resources for genetic diagnosis. We applied these methods for the identification of SMN gene of SMA type I in archival specimens for the prenatal diagnosis. In this study, we performed the prenatal diagnosis with chorionic villus sampling (CVS) cells on two women who had experienced neonatal death of SMA type I. DNA extraction was done from archival slide and tissue materials and PEP-PCR was performed using CVS cells. In order to identify common deletion region of SMN and neuronal apoptosis-inhibitory protein (NAIP) genes, cold PCR-SSCP and PCR-restriction site assay were carried out. Case 1 had deletions of the exons 7 and 8, and case 2 had exon 7 only on the telomeric SMN gene. Both cases were found to be normal on NAIP gene. These results were the same for both CVS and archival biopsied specimens. In both cases, the fetuses were, therefore, predicted to be at very high risk of being affected and the pregnancy were terminated. These data clearly demonstrate that archival slide and paraffin-embedded tissues can be a valuable source of DNA when the prenatal genetic diagnosis is needed in case any source for genetic analysis is not readily available due to previous death of the fetus or neonate.

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Molecular Cloning and Function Analysis of an Anthocyanidin Synthase Gene from Ginkgo biloba, and Its Expression in Abiotic Stress Responses

  • Xu, Feng;Cheng, Hua;Cai, Rong;Li, Lin Ling;Chang, Jie;Zhu, Jun;Zhang, Feng Xia;Chen, Liu Ji;Wang, Yan;Cheng, Shu Han;Cheng, Shui Yuan
    • Molecules and Cells
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    • v.26 no.6
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    • pp.536-547
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    • 2008
  • Anthocyanidin synthase (ANS, leucoanthocyanidin oxygenase), a 2-oxoglutarate iron-dependent oxygenase, catalyzed the penultimate step in the biosynthesis of the anthocyanin class of flavonoids, from the colorless leucoanthocyanidins to the colored anthocyanidins. The full-length cDNA and genomic DNA sequences of ANS gene (designated as GbANS) were isolated from Ginkgo biloba for the first time. The full-length cDNA of GbANS contained a 1062-bp open reading frame (ORF) encoding a 354-amino-acid protein. The genomic DNA analysis showed that GbANS gene had three exons and two introns. The deduced GbANS protein showed high identities to other plant ANSs. The conserved amino acids (H-X-D) ligating ferrous iron and residues (R-X-S) participating in 2-oxoglutarate binding were found in GbANS at the similar positions like other ANSs. Southern blot analysis indicated that GbANS belonged to a multi-gene family. The expression analysis by real-time PCR showed that GbANS expressed in a tissue-specific manner in G. biloba. GbANS was also found to be up-regulated by all of the six tested abiotic stresses, UV-B, abscisic acid, sucrose, salicylic acid, cold and ethylene, consistent with the promoter region analysis of GbANS. The recombinant protein was successfully expressed in E. coli strain with pET-28a vector. The in vitro enzyme activity assay by HPLC indicated that recombinant GbANS protein could catalyze the formation the cyanidin from leucocyanidin and conversion of dihydroquercetin to quercetin, suggesting GbANS is a bifunctional enzyme within the anthocyanidin and flavonol biosynthetic pathway.

Studies on OsABF3 Gene Isolation and ABA Signal Transduction in Rice Plants Against Abiotic Stress (비 생물학적 스트레스 시 벼에서 OsABF3 유전자 분리와 ABA 신호전달 대한 연구)

  • Ahn, Chul-Hyun;Park, Phun-Bum
    • Korean Journal of Plant Resources
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    • v.30 no.5
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    • pp.571-577
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    • 2017
  • Abscisic acid (ABA) is an important phytohormone involved in abiotic stress tolerance in plants. The group A bZIP transcription factors play important roles in the ABA signaling pathway in Arabidopsis but little is known about their functions in rice. In our current study, we have isolated and characterized a group A bZIP transcription factor in rice, OsABF3 (Oryza sativa ABA responsive element binding factor 3). We examined the expression patterns of OsABF3 in various tissues and time course analysis after abiotic stress treatments such as drought, salinity, cold, oxidative stress, and ABA in rice. Subcellular localization analysis in maize protoplasts using a GFP fusion vector further indicated that OsABF3 is a nuclear protein. Moreover, in a yeast one-hybrid experiment, OsABF3 was shown to bind to ABA responsive elements (ABREs) and its N-terminal region found to be necessary to transactivate a downstream reporter. A homozygous T-DNA insertional mutant of OsABF3 is more sensitive to salinity, drought, and oxidative stress compared with wild type plants & OsABF3OX plants. In addition, this Osabf3 mutant showed a significantly decreased sensitivity to high levels of ABA at germination and post-germination. Collectively, our present results indicate that OsABF3 functions as a transcriptional regulator that modulates the expression of abiotic stress-responsive genes through an ABA-dependent pathway.

Studies on the Desertification and Sand Industry Development(II) - Analysis of Silvicultural Techniques and Effects of Landscape-Eco Shelterbelt Establishment - (사막화방지(沙漠化防止) 및 방사기술개발(防沙技術開發)에 관한 연구(硏究)(II) - 중국(中國)의 경관(景觀)-생태(生態) 방호림조성기술(防護林造成技術) 및 효과분석(效果分析) -)

  • Woo, Bo-Myeong;Lee, Kyung-Joon;Jeon, Gi-Seong;Kim, Kyung-Hoon;Choi, Hyung-Tae;Lee, Seung-Hyun;Lee, Byung-Kwon;Kim, So-Yeon;Lee, Sang-Ho;Jeon, Jeong-Ill
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.3 no.3
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    • pp.81-99
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    • 2000
  • The shelterbelts are very important to conserve and protect the sandy land, vegetation coverage, farmland, livestock and human life in the desertified land. The shelterbelts are constructed by the several row-plantings of high-adaptable species in the desertified land. The shelterbelts have various kind of type, and there are shelterbelts for conservation of farmland in dry the region, the protective shelterbelts (windbreaks for blowing-sand, artificial sanddune fixation by revegetation, and construction of farmland shelterbelts to protect farmland and pasture from wind erosion, etc.) in the semi-dry steppe, shelterbelts around the villages and oasis for sanddune fixation, shelterbelts for protection of railroads, and so on. The shelterbelts consist of main she1terbelts and minor shelterbelts. The main shelterbelts were constructed by being perpendicular to main wind direction, and the minor shelterbelts were constructed by being perpendicular to the main shelterbelts. Generally, the width of shelterbelts is 8~20m, and the number of row-planting is 4~10. The grid sizes of shelterbelts networks are $400{\times}400m$, $300{\times}500m$, $100{\times}200m$, and so on, and there are ventilation type and closing type in the type of shelterbelt. The width, number of row-planting, grid size and type of shelterbelt are selected by the local characteristics. The effects of shelterbelts are mainly the climate improvement and mitigation, such as prevention of occurrence of strong wind, cold wind and blowing-sand. And, the other effects of shelterbelts are effect of reforestation, increase of agricultural productions, establishment of greenbelts and green forests, construction of landscape-eco shelterbelts, improvement of life environment of local villages, supply of fuel wood and agricultural wood, land amelioration, effect of revegetation and restoration of desertified land, and so on. The kinds of the tree species mainly used for the construction of shelterbelts have differences between regions, but main species are Populus euphratica, Populus simonii, Populus bolleana, Populus tomentosa, Salix flavida, Salix mongolica, Tamarix chinensis, Hedysarum scoparium, and so on.

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The Study on The ischemic heart disease Explained In Nei-jing(內經) (내경(${\ll}$內經(${\gg}$)에 나타난 허혈성 심질환에 대한 연구)

  • Hong, Tian-Biao;Lee, Won-Chul
    • The Journal of Internal Korean Medicine
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    • v.19 no.1
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    • pp.144-156
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    • 1998
  • This study has been carried out to investigate the cause, pathological mechanism and treatment of symptoms regarded as the ischemic heart disease in Nei-jing(內經). I've got the following conclusions. 1. From the side of xing-bi(胸痺), the ischemic heart disease(IHD) was caused by that the energy in one's heart wasn't extended in the way of Yin-xie(飮邪), namely waste matter of human body and symptoms and treatment wern't written. 2. From the side of xin-bi (心痺), HID was catched by the mechanisms that the blood vessel is blocked. or the heart's blood was deficient owing to the mutation of mo-bi(脈痺), the lack of yang-ming(陽明) and excessive thoughts and worry and others. The symptoms were feeling oppressed in one's brest, palpitating, sudden dyspnea, the dryness of thorat, frequent belching and the fear by the inverse flow of the energy(氣). The treatment was that the yin(陰) was cured immediately, but the yang(陽) mustn't be attacked. 3. From the side of xing-tong(心痛), IHD was suffered from by mechanisms that following the han-sa(寒邪), namely the cold makes a invasion on humanbody, the vessel was blocked, spasm, filled and the amount of blood flow was poor, or caused by injury of vessel, the inverse flow and the disease of shi-dong(是動病) of shou-shao-xin-jing(手少陰心經) and so on. The pain was cramped into the upper and lower back or lower abdomen or throat and accompanied with nausea, abdominal dropsy, constipation, the impending of breathing and so on. The cure was mainly that acupuncture was applied at the jin-su(筋縮) region or meridian in relation to symptoms, but if the pain were severe, acupuncture mustn't be applied. The prog nosis was worse. 4. From the side of xing-tonge(心痛), IHD was divided into zhen-xing-tong(眞心痛) and jue-xing-tong(厥心痛), but pi-xiog-tong(脾心痛) and wei-xing-tong(胃心痛) out of jue-xing-tong(厥心痛) also included the symptoms of the digestive disease.

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Evaluation on Thermal Performance of Thermosyphon by Numerical Analysis (열사이펀의 열성능 산정을 위한 수치해석 연구)

  • Jang, Changkyu;Choi, Changho;Lee, Jangguen;Lee, Chulho
    • Journal of the Korean Geotechnical Society
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    • v.30 no.9
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    • pp.57-66
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    • 2014
  • The ground in cold region consists of active and permafrost layers. The active layer at the unstable state may cause ground corrosion and uplift, when the temperature of frozen ground increases due to seasonal changes. The thermosyphon is one of the stabilization methods to maintain the ground stability in the frozen ground. The thermosyphon is a closed two-phase convection device that extracts heat from the ground and discharges it into the atmosphere. In this study, ground freezing experiment using a thermosyphon and simulated ground with the isolation material was conducted to evaluate the thermal performance of the thermosyphon. In order to consider the thermal performance of the thermosyphon, commercial numerical program (TEMP/W) was adopted. Likewise, the thermal performance of thermosyphon and thermal properties of ground were applied in the numerical model. In a series of comparisons with experiment results and numerical study, thermal performance of thermosyphon can be evaluated.

Testing the Convergence of Military Expenditure and Arms Imports in Northeast Asian Countries (동북아 국가의 국방비 지출 및 군수물자 수입 수렴성 검정)

  • Rhee, Hyun-Jae
    • The Journal of the Korea Contents Association
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    • v.13 no.2
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    • pp.475-487
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    • 2013
  • The aim of this study is to examine an existence of mutual interdependency in terms of military expenditure and arms imports between Northeast Asian countries such as South Korea, North Korea, China, Japan, and U.S. Recently, the mood of post cold war and intensified globalization lead to be disarmament in pursuing a policy on national defence in many countries. Since potential menace to national security has been receiving more concern rather than a direct armed clash, mutual interdependency on military spending should be fully understood. For a methodological tools, ${\beta}$ and ${\sigma}$-convergences, convergence with rational expectation, and Granger causality test are employed. Empirical evidence shows that the convergences which are evaluated by ${\beta}$, ${\sigma}$, and by a model based on rational expectation are in general revealed, and differences are more sensitive to a military decision making procedures. Granger causality, however, is not being existed. To this end, it would be concluded that the Northeast Asian countries are going with a trend in the world than forming their own tendency in this region.