• Title/Summary/Keyword: 동결토

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A Study on Environmentally Friendly Soil Pavement Materials Using Weathered Soil and Inorganic Binder (화강풍화토와 무기질 결합재를 활용한 친환경 흙포장에 관한 연구)

  • Jung, Hyuksang;Jang, Cheolho;An, Byungjae;Chun, Byungsik
    • Journal of the Korean GEO-environmental Society
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    • v.10 no.4
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    • pp.25-31
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    • 2009
  • In this study, the problem of existing soil pavement is a long-term durability lack and crack occurrence. It complements in order to develop the environmental soil pavement material which composites readily blended mineral binder of liquid and decomposed granite soils. It was estimated optimal mixture proportion for unconfined compressive strength, permeability, $Cr^{6+}$detection test, SEM test with age, freezing and thawing test. It resulted mixture proportion of powder types mineral binder for rates of cement : fly ash : plaster was optimal rates of 50 : 33 : 7, and $Cr^{6+}$detection test as a result was a slight production. SEM test with 3days as a result was made Ettringite. It was found that this material was early development of early-strength for chemical. This study indicated that it will execute field appliciability Evaluation test, examination of soil pavement method with decomposed granite soils and mineral binder.

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Development of Analytical Model for Cement Concrete Pavements Considering Joint Behavior (줄눈부의 거동을 고려한 시멘트콘크리트 포장체의 해석모델 개발)

  • 변근주;이상민;임갑주
    • Magazine of the Korea Concrete Institute
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    • v.2 no.4
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    • pp.91-98
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    • 1990
  • Joints are provided in cement concrete pavements to control transverse and longitudinal cracking that occur due to restrained deformations caused by moisture and temperature variations in the slab. But the constuction of joints reduces the load-carrying capacity of the pavement at the joints, and pavements have been deteriorated by cracks at the slab edges along the joints due to traffic loads. Therefore, it is important to analyze the behavior of joints accurately in the design of cement concrete pavements. In this study, the mechanical behavior of cement concrete pavement slabs is analyzed by the plate-finite element model, and Winkler foundation model is adopted to analyze the subgrades. The load transfer mechan¬ism of joints are composed of dowel action, aggregate interlocking, and tied-key action, and the analytical pro¬gram is developed using these joint models. Using this numerical model as an analysis tool, the effects of joint parameters on the behavior of pavements are investigated.

Sinoatrial Reentrant Tachycardia in a Yorkshire Cross Dog (요크셔테리어 잡종견에서 나타난 동방회귀성 빈맥증)

  • Nam, So-Jeong;Hyun, Chang-Baig
    • Journal of Veterinary Clinics
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    • v.25 no.5
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    • pp.391-395
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    • 2008
  • An 8-year-old intact male Yorkshire cross dog (7.5 kg of body weight) was referred with the primary complaint of exercise intolerance and occasional syncope. Initial cardiological examination could not identify any abnormalities except mild mitral regurgitation. Exercise stress test revealed chronotrophic incompetence. Furthermore the 1 hr-digital event recording found the sudden onset of paroxysmal sinus tachycaridas (156-172 bpm) lasting few minutes and stopping abruptly. In addition, the tachycardia terminated by vagal maneuver and verapamil administration. Based on this finding, the case was diagnosed as sinoatrial reentrant tachycardia (SART). The dog was treated with diltiazem and enalapril. Although the dog still has exercise intolerance, no syncope has been observed after medication.

Field Tests for the Application of Bottom Ash and Shred Tire as Fill Materials (석탄회 및 폐타이어의 성토재로의 적용성 검토를 위한 현장시험)

  • Lee, Sungjin;Lee, Taeyoon
    • Journal of the Korean GEO-environmental Society
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    • v.14 no.10
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    • pp.29-37
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    • 2013
  • In this study, we constructed the test embankment with four kinds of sections(2 kinds of bottom ash; tire shred-bottom ash mixture, weathered soil) in field and had been monitoring the behaviour of the test embankment and change of ground water quality for 1 year. In the geotechnical aspects, there was no relative difference of deformation in 4 test materials section and we could not see the possibility of the strength-reduction of coal ash materials by freezing inside of the embankment. In addition, no settlement was observed in the test sections because the base soil of the test sections was rigid enough that no consolidation was occurred. In the examination of water quality, all of the heavy metals and negative ions were detected below the drinking water standards except for sulfate($SO_4^{2-}$). In the beginning of measurement, higher concentrations of sulfate from 4 test sections were detected than drinking water standard for 20 days after beginning of the test but the concentrations decreased below the drinking water standard after 50 days after the tests.

Electron Transport Carrier for the Free Radical Shethna Flavoprotein in Azotobacter vinelandii (Azotobacter vinelandii Shethna Flavoprotein 의 Free Radical 생성(生成)을 위(爲)한 전자전달물질(電子傳達物質)-)

  • Chun, Jae-Kun;Tollin, Gordon
    • Applied Biological Chemistry
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    • v.16 no.1
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    • pp.31-40
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    • 1973
  • Azotobacter vinelandii cell extracts and its variety of purified fractions with regard to their ability to form the redox state of the Shethna Flavoprotein (free radical form FPH.) were studied. A fluorescent flavoprotein (protein I) and a brown protein (protein II) were the most active proteins which were isolated in purified form. The free radical formation activity was substantially decreased during the purification and was completely lost upon storage in a week under nitrogen in a frozenstate. The presence of free flavin (FMN) with NADH enhanced the rate of free radical formation. The reaction of FMN and NADH was found to be catalysed by various cell fractions. A possible role of FMN as a substrate for free radical shethna flavoprotein was investigated. Slower reaction rate of $FMNH_2+Flavoprotein\;(FP){\to}FPH+FMN$ than $FMN+NADH{\to}FMNH_2$, accumulation of $FMNH_2$ ocurred which subsquently caused FPH.

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소 수정란이식에 있어서 효율적 발정동기화 처리법에 관한 연구

  • 윤종택;이호준;최은주;정경섭;신용순;민관식;이종완
    • Proceedings of the KSAR Conference
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    • 2003.06a
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    • pp.93-93
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    • 2003
  • 소의 수정란이식에 있어서 성공적인 임신을 위해서는 수란우의 적절한 영양상태, 양질의 수정란, 이식 시술자의 기술력과 수란우와 수정란의 적절한 동기화가 필수 요인이라 사료된다. 특히, 적절한 동기화를 위해서 발정관찰은 필수적이지만 번거롭고 장시간동안 관찰을 해야 하는 단점이 있다. 따라서 본 연구에서는 이러한 단점을 보완할 수 있도록 발정동기화 처리방법을 비교, 검토하여 수정란이식에 있어서 효과적인 발정동기화 방법을 모색하고자 실시하였다. 발정동기화 방법은 Fig 1과 같이 CIDR처리방법(A군)과 GnRH 처리방법(B군)을 사용하였으며, 황체의 등급은 직장검사와 초음파 진단기를 이용하여 직경이 2cm 이상, 1~2cm와 1cm 미만의 황체를 각각 1등급, 2등급과 3등급으로 분류하였다. 또한 본 실험에 공시된 수정란은 체외 생산된 한우 배반포기의 수정란을 사용하였으며, 1등급의 황체를 가진 수란우만을 선별하여 비외과적인 방법으로 황체가 존재하는 자궁각심부에 이식하였다. 임신진단은 이식 후 45~60일에 직장검사와 초음파진단을 이용하여 실시하였다. 발정동기화처리결과는 Table 1에서 보는 바와 같이 A군과 B군에서 발정발현율이 각각 100%와 96%로 나타났으며, 이식하기에 적합한 1등급 황체의 출현율이 65.4%와 56%로 A군에서 다소 높게 나타났다. 발정동기화 처리방법에 따른 수정란 이식 후 수태율은 A군에서 신선란과 동결란일 때 각각 66.7%와 60%로 나타나 B군의 22.2%와 0%의 결과보다 유의적으로 높은 결과를 나타내었다. 따라서 본 연구의 결과로 미루어 볼 때 수정란 이식을 위한 발정동기화 방법은 CIDR 처리방법을 적용하는 것이 GnRH 처리방법 보다 효율적이라 사료된다.다. 특히 기능황체에서의 특이적 발현 spot을 확인할 수 있었다. 이러한 결과들로부터 황체의 progesterone분비기능의 역할을 수행하기 위한 단백질들이 전, 중기에 발현된다는 것을 알 수 있고 퇴행황체에서는 발현이 안되고 있는 것을 알 수 있다. 이러한 결과를 토대로 다른 양상을 띤 spot을 분리하여 어떤 단백질인지를 분석하여 각각의 황체단백질의 특성을 규명할 수 있을 것으로 사료된다.적율(HCT)을 이루고 있음을 알 수 있었다. 적혈구 평균용적(Mean Corpuscular Volume ; MCV), 평균적혈구혈색소량(Mean Corpuscular Hemoglobin ; MCH), 평균적혈구혈색소농도(Mean Corpuscular Hemoglobin Concentration ; MCHC) 그리고 혈소판(Platelets) 분석결과 형질전환돼지가 일반돼지보다 약간 높은 수치를 나타냈으며 변화양상 또한 유사한 결과를 나타내었다. 이와 같은 시험분석결과를 토대로 사람 조혈촉진유전자(hEPO)가 형질전환된 돼지는 유즙으로 발현할 수 있도록 형질전환 되었음에도 불구하고 헤모글로빈 및 적혈구가 증가함으로서 형질전환돼지 개체의 혈장으로도 사람 조혈촉진인자가 분비하고 있음을 간접적으로 알 수 있었다. 정상돼지 보다 형질전환돼지가 약 30% 높은HCT 수준을 보였으며 이러한 현상은 사람에서는 적혈구증다증(erythrocytosis)으로 분류되고 있다. 이에 대한 고찰은 형질전환돼지 자체의 생리적 문제점(side effects)에 대한 해결과 더불어 기존의 인간질병에 대한 모델동물로서의 이용 가능성을 제시할 수 있는 것으로 사료된다.mu\textrm{m}$ 300BG는 56.32$\mu\tex

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Cytotoxic Effect of X-irradiation of Mouse Tumor Cells in the Presence of Korean Ginseng Extract (마우스 종양세포의 세포독성에 미치는 인삼 추출액과 방사선조사의 병용 효과)

  • Kwon Hyoung-Cheol;Kim Jin-Ki;Kim Jung-Soo;Choi Dong-Seong
    • Radiation Oncology Journal
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    • v.18 no.3
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    • pp.200-204
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    • 2000
  • Purpose : We already reported the results that aqueous extract of Korean ginseng roots showed a marked cytotoxicity. In this study, we investigated whether combined ginseng product with X-irradiation increase the cytotoxicity of tumor cells than X-irradiation or not. Materials and Methods : Fifty gram of Korean ginseng powder mixed with 1 L of distilled water was extracted with reflux flask under condition of $100^{\circ}C$ for 5 hrs. This aquaous ginseng extract was filtered, centrifuged and then was freezed under condition of $-90^{\circ}C$ for 16-18 hrs. The freezing extract was dried with freeze drier, and then diluted. X-irradiation was given to tumor cells by 6 MeV linear accelerator. The cytotoxicity of ginseng in vitro was evaluated from its ability to reduce the clonogenecity of fibrosarcoma (FSa II) cells. In X-irradiation alone group, each 2, 4, 6 and 8 Gy was given to tumor cells. In X-irradiation with ginseng group, 0.2 mg/mL of ginseng extract was exposed to tumor cells for 1 hour before X-irradiation. Results : The yield for 50 g of ginseng extract which was treated with freezing drier was 3.13 g($6.3\%$). Cytotoxicity In vitro was measured as survival fraction which was judged from the curve, at ginseng concentration of 0.001, 0.01, 0.1 and 1 mg/mL were $0.89\pm0.04$, $0.86\pm0.06$, $0.73\pm0.01$ and $0.09\pm0.02$, respectively. Survival fraction at X-irradiation alone of 2, 4, 6 and 8 Gy were $0.81\pm0.07$, $0.42\pm0.08$, $0.15\pm0.02$, $0.03\pm0.01$, respectively. But, suwival fraction in combined group of X-irradiation and ginseng (0.2mg/ml) at each same radiation dose were $0.28\pm0.01$, $0.18\pm0.03$, $0.08\pm0.02$, $0.006\pm0.002$, respectively (p<0.05). Conclusion : The yield for ginseng extract which was treated with freezing drier was $6.3\%$. Cytotoxicty of Fsa 11 in combined ginseng with X-irradiation group was increased than that of X-irradition alone group, and its enhancing effect seemed to be added.

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Morphogenetic Environment of Jilmoe Bog in the Odae Mountain National Park (오대산국립공원 내 "질뫼늪"의 지형생성환경)

  • Son, Myoung-Won;Park, Kyeong
    • Journal of the Korean association of regional geographers
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    • v.5 no.2
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    • pp.133-142
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    • 1999
  • The wetland is very important ecologically as a habitat of diverse organisms. The purpose of this paper is to elucidate the morphogenetic environment of Jilmoe Bog found in the Odae Mountain National Park Jilmoe Bog is located in the high etchplain(1,060m) where Daebo Granite which had intruded in Jura epoch of Mesozoic era has weathered deeply and has uplifted in the Tertiary. The annual mean temperature of study area is $5.3^{\circ}C$, the annual precipitation is 2,888mm. The minimun temperature of the coldest month(january) is below $-30^{\circ}C$ and the depth of frozen soil is over 1.6m. Jilmoe bog consists of a large bog and a small bog. The length of the large bog is 63m and its width is 42m. The basal surface of Jilmoe bog is uneven. Jilmoe bog is a string bog fanned due to frost actions. In String bog, its surface is wavy with stepped dry hills and net-like troughs crossing hill slope. It seems that string bog is related to the permofrost or seasonal permofrost of cold conifer forest(taiga) zone(where the depth of frozen soil is very deep in the least in winters). String bog is a kind of thermokarst that frozen soil thaws differentially locally in declining permofrost and ground surface becomes irregular. There is turf-banked terracette of width $30{\sim}40cm$ in the headwall of small cirque-type nivation hollow formed at footslope of Maebong mountain around Jilmoe bog. This turf-banked terracette is formed by the frost growth of soil water below grass mat in periglacial climate environment. Where water is plentiful such as a nivation follow${\sim}$valley corridor and a headwall of valley, turf patterned grounds of width $30{\sim}50cm$ are found. This turf patterned ground is 'unclassified patterned ground', earth hummock. In conclusion, Jilmoe bog is a string bog of thermokarst that the relief of ground surface is irregular according to locally differentially thawing of permofrost(frozen soil). Jilmoe bog is high moor, its surroundings belongs to periglacial environment that turf-banked terracette and turf patterned ground are fanned actively.

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A historical study on the flexibility square-format typeface and the prospects - Focused on the three-pairs fonts of hangeul - (탈네모글꼴에 관한 역사적 연구와 전망 - 세벌식 한글 글꼴을 중심으로 -)

  • Yu, Jeong-Mi
    • Archives of design research
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    • v.19 no.2 s.64
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    • pp.241-250
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    • 2006
  • Hangeul as the Korean unique characters were invented according to some character-making principles and based on scholars' exhaustive researches. While most of the characters in the world evolved naturally, Hangeul was invented based on a precise linguistic analysis of the time, and therefore, it is most scientific and reasonable among various characters throughout the world. Nevertheless, Hangeul typeface designs do not seem to inherit the ideology of scientific and reasonable Hangeul correctly. For the square forms have been used intact due to the influences from the Chinese characters which prevailed during the time. If a single set of square characters should be designed, as much as 11,172 fonts should be designed, which suggests that advantages of Mangeul may not well be used fully; Hangeul was invented to visualize every sound with the combinations of 28 vowels and consonants. Problems of such square fonts began to be identified since 1900's when typewriters were introduced first from the West. Since a typewriter is designed with 28 characters laid out on its keyboard by using such combinations, the letters may be easily combined on it. The so-called the flexibility square-format typeface was born as such. Specially, the three-pairs fonts of these can be combined up to 67 letters including vowels and consonants. The three-pairs fonts system can help to solve the problems arising form the conventional square fonts and inherit the original ideology of Hangeul invention. This study aims to review the history of the three-pairs fonts designs facilitated by mechanic encoding of Hangeul and thereupon, suggest some desirable directions for future Hangeul fonts. Since the flexibility square-format typeface is expected to evolve more and more owing to development of the digital technology, they would serve our age of information in terms of both functions and convenience. Just as Hunminjongum tried to be literally independent from the Chinese characters, so the flexibility square-format typeface designs would serve to recover identity of our Hangeul font designs.

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Effects of Low-quality Aggregates in the Same Workability Conditions on the Engineering Properties of Concrete (저품질 골재가 동일 작업성 조건에서 콘크리트 공학적 특성에 미치는 영향)

  • Min, Kyeong-Chul;Han, Cheon-Goo
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.4 no.3
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    • pp.299-306
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    • 2016
  • In this research, influence of low quality aggregate on engineering properties of concrete was evaluated experimentally. From the experiment, the fresh properties of slump and air content were controlled with unit water and AE dosage and all mixture were designed to have similar fresh properties of slump and air content with various quality of aggregate. Under this conditions, comparing with the mixture with high quality aggregate, the mixture with low quality aggregate showed the unit water and AE dosage were increased about 18 and 98%, respectively, because of poor grading and quantity of fines. For compressive strength, the low quality aggregate, specifically, exploded debris, clay sand, and sea sand contributed on decreasing compressive strength about 20~35%. Additionally, the concrete mixture including low quality fine and coarse aggregate showed adverse quality in not only compressive strength but also durability of freeze-thawing resistance, drying shrinkage, carbonation, and chloride ingression. Therefore, it is considered that for low quality aggregate, extra treatment processes such as washing or controlling gradation, and regulation to limit the use of low quality aggregate are needed.