• Title/Summary/Keyword: 보 붕괴

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Rheological Properties of Rehydrated Suspensions of Freeze Dried Kochujang Powders (동결건조 분말고추장의 재수화시 리올로지 특성)

  • Kim, Suk-Shin;Chang, Kyu-Seob;Yoon, Han-Kyo;Lee, Sang-Kyu;Lee, Shin-Young
    • Korean Journal of Food Science and Technology
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    • v.19 no.2
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    • pp.81-88
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    • 1987
  • Rheological properties of rehydrated suspensions of two kinds of freeze dried Kochujang powders, processed at different freezing rates, were compared with raw Kochujang using Brookfield wide-gap rotational viscometer at $25^{\circ}C-60^{\circ}C$. Shear rates ranged from $0.1965\;sec^{-1}$ to $1.9650\;sec^{-1}$ and solid content ranged from 47% to 56%. Rehydrated suspensions of quickly frozen Kochujang powder and slowly frozen Kochujang powder, and raw Kochujang exhibited pseudoplastic behaviors with yield stress and presented thixotropic properties which followed the second-order kinetic behavior proposed by Tiu. Suspensions of Kochujang powders exhibited considerably higher decaying rates than raw Kochujang. The dependency of the equilibrium structure parameter on the shear rate was weak, and there were no significant differences among the values of structure parameters of three samples. The temperature dependency of the apparent viscosity of Kochujang suspension was fully expressed by Arrhenius equation and activation energies of suspensions of quickly frozen Kochujang powder and slowly frozen Kochujang powder, and raw Kochujang were 2.21, 2.18, and 2.32 Kcal/g.mole respectively. Consistency indices of three samples increased with solid content and decreased with temperature. Flow behavior indices of three samples showed no considerable dependency on the temperature and solid content. There were no significant differences in the rheological properties between two Kochujang powders.

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Studies On the Cellulase [IV.] -On the Properties of Crude Cellulase produced by Trichoderma viride($O_2-1$) (섬유소(纖維素) 분해효소(分解酵素)에 관(關)한 연구(硏究) (제4보(第4報)) -Trichoderma viride($O_2-1$)가 생성(生成)하는 조효소(粗酵素)의 성질(性質)에 대(對)하여-)

  • Sung, Nack-Kie
    • Applied Biological Chemistry
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    • v.12
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    • pp.25-31
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    • 1969
  • The characteristics of crude enzyme produced from Trichoderma viride($O_2-1$) which isolated from half spoiled Locust acacia wood (Robinia Pseudacacia Linne) were examined in this paper. The results obtained were summarized as follows: 1) As a results of enzymatic action on several cellulose substrate it was found that there were some sorts of cellulase in crude enzyme. 2) The activity of C.M.C. ase and ${\beta}-glucosidase$ were decreased in accordance with increasing concentration of substrate, and filter paper saccharifying enzyme relatively increased in accordance with increasing concentration of substrate and enzyme in couse of time. 3) The optimal pH of each enzyme was 5.0 and the range of stability on pH generally from 3 to 6. 4) In disintegrating activity on filter paper, in decomposing activity on C.M.C. and $p-nitrophenyl-{\beta}-D-glucoside$, and in saccharifying activity on filter paper, the optimal temperatures were $50^{\circ}C.,\;60^{\circ}C,\;and\;65^{\circ}C$. 5) The order of stability on temperature was as follow; saccharifying activity on filter paper decomposing activity on C.M.C. disintegrating activity on filter paper>decomposing activity on $p-nitrophenyl-{\beta}-D-glucoside$. 6) The activity of the enzymes was inhibited with mercuric and silver ion, and activated with potassium.

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Distribution of Some Environmental Radionuclides in Rocks and Soils of Guemjeong-Gu Area in Busan, Korea (부산시 금정구 일대 암석 및 토양에서 일부 환경방사성 핵종들의 분포 특성)

  • Lee, Hyo-Min;Moon, Ki-Hoon;Kim, Jin-Seop;Ahn, Jung-Keun;Kim, Hyun-Chul
    • The Journal of the Petrological Society of Korea
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    • v.17 no.3
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    • pp.179-190
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    • 2008
  • The distribution characteristics of some major environmental radionuclides ($^{40}K$, $^{228}Ac$, $^{226}Ra$, $^{222}Rn$) and U in rocks, soils and soil gas were studied at Geumjeong-Gu, Busan, Korea. The activities of radionuclides in granitic rocks are decreased in the odor of $^{40}K$>thorium decay series>uranium decay series. This reveals that Th was relatively more enriched in granitic rocks than U. The U content and activity of $^{226}Ra$ and $^{228}Ac$, however, don't reflect the fractionation sequence of granitic rocks in the study area. The activities of all these radionuclides and U content in soils are generally higher than in rocks, and their distribution in rocks, soils and soil gas show very low co-relationship. These facts indicate that the activities of radionuclides in soil and soil gas were greatly affected by leaching and adsorption properties of the radionuclides and their parents during weathering and pedogenetic process rather than their concentrations in parent rocks.

A Study on Brace-height Ratio for Seismic Retrofit of School Building (학교 건축물의 내진 보강을 위한 가새 - 높이비에 관한 연구)

  • Lee, Hwa-Jung;Byon, Dae-Kun;Yoon, Sung-Kee
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.24 no.4
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    • pp.10-17
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    • 2020
  • The recent earthquake in Korea caused large and small damages to many school building. School building is an important building that is used as a shelter in the event of disaster. Among the seismic retrofit methods, the internal steel braced frame type method is used for its relatively easy construction and excellent performance. In this study, the maximum shear force and displacement were compared and examined by applying the brace frame to existing concrete school buildings. As a result, we verified the adequacy of the analytical model and compared and examined the effect of brace-height ratio on the span of the existing school buildings. The adequacy of the maximum shear force and displacement relationship can be confirmed in the model with a length of 0.3. In addition, seismic frame was applied to the actual non-seismic reinforced concrete school building, and the seismic performance was evaluated by nonlinear static analysis(Push-over analysis) according to the ratio of brace-height. As a result, the increase of the brace-height according to the brace-height ratio has the effect of increasing the maximum shear force and maximum load at the performance point. But the collapse of the braced frame due to the increase in the lateral stiffness occurred, indicating that seismic retrofit according to the proper brace-height is necessary. Therefore, in the seismic retrofit design of brace frame of existing school building, it is necessary to select the proper brace-height after retrofit analysis according to the brace-height ratio.

Seismic Performance Evaluation of Steel Moment Resisting Frame Systems According to an Improved Design Method of RBS-B Connections (RBS-B 접합부 설계식 개선에 따른 철골모멘트골조 시스템의 내진성능평가)

  • Han, Sang-Whan;Kang, Ki-Byung;Moon, Ki-Hoon;Hwang, Seong-Hoon
    • Journal of the Earthquake Engineering Society of Korea
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    • v.14 no.6
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    • pp.75-84
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    • 2010
  • In current seismic design provisions, a reduced beam section with bolted web (RBS-B) connections is only permitted for intermediate moment frames (IMF). This study evaluated the seismic performance of steel moment resisting frame systems having RBS-B connections designed according to current seismic design provisions. For this purpose, 12 archetypal IMF systems having two different span lengths (9m, 6m) were designed considering two design load levels (SDC $C_{max}$, SDC $C_{min}$). A nonlinear analytical model that can simulate hysteretic behavior of an RBS-B connection was also developed in this study. The procedures specified in ATC 63 are used to conduct a seismic performance evaluation. Moreover, this study conducts the seismic performance evaluation of IMF systems designed according to a new design method proposed by the authors in the previous study. It was observed that several model frames designed according to current seismic design provisions did not provide satisfactory collapse margin ratios (ACMR). This study also showed that the model frames designed according to the new design procedures had a sufficient ACMR.

Design Standard and Improvement Proposal of Slope (국내외 비탈면 설계기준 및 개선방안(설계안전율 중심으로))

  • Yu, Byeong-Ok;Song, Pyeong-Hyeon
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.296-296
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    • 2008
  • 국내 절토비탈면은 이상 기후 및 건설공사의 증대로 인해 증가하고 있는 추세이며 장마철 및 태풍으로 인해 비탈면의 붕괴로 많은 인명 및 재산피해가 발생되고 있는 실정이다. 국내에서 사용되고 있는 기존의 비탈면의 설계기준은 암반의 불연속면에 대한 조사를 실시하고는 있지만 주로 암반의 굴착난이도를 토층, 리핑암, 발파암으로 구분하여 각각의 비탈면 절취경사를 결정하여 사용하는 방법을 사용하였으며 이러한 기준은 단순히 암석의 강도를 기준으로 설정되어 있으므로 암석의 공학적 특성 즉, 암반내 불연속면 방향성, 연속성, 충진물질, 마찰각, 풍화속도 등의 영향으로 공용후 비탈면 구배의 재조정 및 보강이 빈번하다. 국내외 절토비탈면의 설계기준은 각 기관별로 산재되어 있었으며 비탈면에 대한 설계 및 시공 등에 관한 기준은 도로와 철도 설계기준에 일부 반영되어 있을 뿐 항만, 댐, 택지조성 등 기타 시설 설계기준에는 비탈면에 대한 기준이 마련되어 있지 않아 표준적인 비탈면 설계기준 및 유지관리지침이 등이 필요하였다. 이러한 문제점을 보완하기 위해 2004년부터 2006까지 한국시설안전공단, 한국도로공사, 대한주택공사가 협동으로 연구한 건설공사 비탈면 설계 시공 및 유지관리에 관한 연구의 결과로 2006년도에 "건설공사 비탈면 설계기준"이 수립되었다. 이 설계기준은 건설공사에서의 기존 상이한 기준들을 정리하고 동일화하는 작업을 수행하였으며 지반의 조사에서부터 대책공까지를 막나하여 정리하였다. 그러나 최근에 급격한 기후변화로 인한 비탈면붕괴 빈번함에 따라 과거 적용되어 왔던 이들 기준을 적용하는 경우, 특히 상부 토층 및 풍화암 구간에서 많은 설계안전율을 만족하지 못해 많은 보강을 수반해야 하는 문제가 발생되고 있어 그 원인에 대한 분석을 수행하고자 하였다. 2006년도 정리된 기준은 과거에 적용하여 온 유기시의 안전율 조건을 Fs > 1.1~1.2을 적용하였던 것을 Fs > 1.2로 통일하였으며 지하수위 조건은 지표면에 위치하도록 하였다. 지하수위 조건은 풍화암 및 토층의 경우, 과거 지표면에 -3m를 적용한 시기가 있었으나 지표면에 지하수위를 적용하는 것이 일반적인 해석방법이다. 이러한 결과의 원인을 검토해 보면 다음과 같다. 첫째, 풍화암 및 토층에 적용되어 온 지반강도 정수가 과거 적용한 값보다 최근에는 작아지는 경향을 보이고 있다. 둘째, 지하수위 적용문제로 현재 지표면에 지하수위를 두어 안전율을 감소시키는 문제로 이는 최근 들어 많은 연구기관에서 강우시 간극수압의 증가에 대한 연구가 활발하게 진행되고 있다. 그러나 침투수 해석은 현행 기준에도 강우의 침투를 고려한 해석을 실시하는 경우 FS > 1.3 적용하는 것으로 되어 있으나 대부분의 해석에서는 적용이 되지 못하고 있는 실정이다. 셋째, 안전율이 과거에 주로 적용된 Fs > 1.1에서 Fs > 1.2로 상향 조정되어 우기시의 설계안전율 만족시키지 못하는 문제이다. 그러므로 이러한 문제점을 개선하기 위한 검토가 필요하며 장기적으로 이에 대한 합리적인 기준을 개정하는 작업이 추후에 수행되어야 할 것으로 판단된다.

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Using implants for worn dentition with the altered vertical dimension of occlusion based on shortened dental arch concept: a case report (과도한 마모를 보이는 환자에서, 임플란트를 활용해 수직 고경을 증가시키며 shortened dental arch 개념을 적용한 보철 수복 증례)

  • Lee, Jae Hyun;Kim, Tae Su;Lee, Chul Won;Lee, Won Sup;Lee, Su Young
    • The Journal of Korean Academy of Prosthodontics
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    • v.54 no.1
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    • pp.49-56
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    • 2016
  • Excessive occlusal wear can result in unacceptable damage to the residual teeth structure, anterior guidance and masticatory function. An 86-year-old man presented with worn dentition and anterior deep bite due to loss of the posterior support. Two implants covered by Korean national health insurance, fixed partial denture and direct composite resin were used to restore the dentition, instead of removable prosthesis. The occlusal vertical dimension was increased by 2 mm in the premolar area and shortened dental arch concept was applied. This treatment was a less expensive alternative to full-mouth rehabilitation with positive esthetic and functional outcomes after 7 months of follow-up.

A Study on the Social Functions of Sijo (시조의 사회적 기능 고찰 - 조선조 사회와 시조의 관계를 중심으로 -)

  • 박규홍
    • Sijohaknonchong
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    • v.19 no.1
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    • pp.127-153
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    • 2003
  • In early Josun(朝鮮) era, the scholars, genteels, and high officials in Josun dynasty paid attention to Sijo(時調) who hoped Josun society would share Confucian values. Sijo poems written by them are based upon Confucian ideology, giving an opportunity to its members to make sure their homogeneity and helping Josun dynasty sustain its regime. Gyongichega(景幾體歌) has, however, already failed to be an appropriate genre to do these functions. Nevertheless, in the late Josun dynasty when there were agitation in class hieracy, development of currency economics, maldistribution of wealth, and pursuit of enjoyment, obscene poems turned out. Consequently these songs contributed to encroaching and eventually destroying the Josun dynasty. The question that who are in charge of creating and enjoying Sasulsijo(辭說時調) cannot be answered by approaching it in the social class point of view. The range of the maker or the reader of Sasulsijo in the late Josun dynasty was much more extensive than that in the early times. Not only aristocracy or the middle society but even some of the lower class may have made and enjoyed those songs. In the meantime, it is singer-songwriters whom Park, Hyogwan blamed for their profiteering abuse of obscenity that is supposed to have been mainly reponsible for the creation of those songs. Siga is a double-edged art in its essence--the good and the bad. The lewd songs were, in the early Josun, strictly controlled but in the late Josun dynasty, were thriving due to social changes. In this context, songs based on Confucian ideology as well as the ones focused on sexual love became decayed along with the collapse of the Josun dynasty. Even though, in the light of the history of Siga, those two types of Siga are underestimated in its artistic value, they have very special social historical meaning in doing positive and negative functions for existence and destroy of the Josun dynasty.

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Types and Characteristics of Landslides in Danyang Geopark (단양 지질공원 내의 산사태 유형과 특징)

  • Seong-Woo Moon;Ho-Geun Kim;Yong-Seok Seo
    • The Journal of Engineering Geology
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    • v.33 no.3
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    • pp.427-438
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    • 2023
  • We carried out a geological survey to classify the types of mass movement in Danyang Geopark (where various rock types are distributed) and analyzed the mechanical and hydraulic characteristics of landslide materials using a series of laboratory tests. Debris flows occurred in areas of limestone/marble, shale, and porphyroblastic gneiss, and limestone/marble landslides were distinguished from the others through the presence of karren topography. Soil tests showed that soil derived from weathered gneiss, which has a higher proportion of coarse grains, has a higher friction angle, lower cohesion, and larger hydraulic conductivity than soils from areas of limestone/marble, and shale. Rock failure mass movements occurred in areas of phyllite, sandstone, and conglomerate and were subdivided into plane failure, block-fall, and boulder-fall types in areas of phyllite, sandstone, and conglomerate, respectively. The shear strength of phyllite is much lower than that of the other types of rock, which have similar rock quality. The slake durability index of the conglomerate is similar to that of the other rock types, which have similar degrees of weathering, but differential weathering of the matrix and clasts was clearly observed when comparing the samples before and after the test. This study can help establish appropriate reinforcement and disaster prevention measures, which depend on the type of mass movement expected given the geological characteristics of an area.

Ultrasonic Properties on Building Stones, Characteristics of Structural Deformation and Conservation States of the Sanctuary in Wat Phou Temple of Champasak, Lao PDR (라오스 밧푸 주사원의 보존현황과 석재의 초음파 물성 및 구조적 변형특성)

  • Lee, Chan Hee;Shin, Hyo Cheol;Han, Doo Roo
    • Journal of Conservation Science
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    • v.33 no.6
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    • pp.399-416
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    • 2017
  • The 'Wat Phou and Associated Ancient Settlements within the Champasak Cultural Landscape' of Laos was designated as a UNESCO World Cultural Heritage in 2001. The uppermost structure of the Sanctuary in Wat Phou has been destroyed and being variably damaged, maintenance is required through scientific and systematic diagnosis. The Sanctuary of Wat Phou was constructed mainly using sandstones and bricks. There are physical damages including fracture, break out, exfoliation and interval as well as biological damages by lichen, mosses and weeds. According to the ultrasonic velocity measurement and property evaluation of the sandstones of the Sanctuary in Wat Phou, weathering index of the eastern side sandstones is 0.10 to 0.74 (mean 0.36), showing MW grade. Southern and northern side sandstones have relatively higher properties with average weathering indices of 0.30 and 0.32. The results of slope analysis of the Sanctuary, indicated that the 4th spot in the southern side has the largest slope of $5^{\circ}W$, seemingly due to the unstable ground around the Sanctuary. Based on the relative level measurement and past drawings, the Sanctuary is verified to have been located on ground with a certain slope rather than flatland. The ground of the southern side is inclined $1.51^{\circ}$ more than that of the northern side, which will affect the structural stability of the temple. The interval width of the selected southern spot is the largest with an average width of 159.5 mm, and the largest width is 328.3 mm at the top, since the width increases above rather than below, seemingly due to the unequal subsidence of the ground. Constant maintenance for conservation is required for the structural stability of the Sanctuary in Wat Phou, which was partly collapsed and has also suffered physical damage.