• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 추계학술발표회
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• pp.107-111
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• 2003

Estuary of Nakdong river area is composed of unconsolidated sediments including clays that are deposited varying from 40 to 70m thick. The purpose of research is the knowledge of the correlation between engineering properties and mineralogy of clay sediments. The correlation analysis carry out multiple regression that have independent variables (Engineering properties) and dependent variables (mineralogy, geochemistry). Engineering properties of clay are correlated with the mineral compositions and geochemical characteristics. The result of the analysis is Wn=-0.6 Feldspar ＋ 1.1 pH ＋ 0.01 TDS ＋ 27.5, Ip=0.36 Clay ＋ 1.44 Vermiculite ＋ 0.94 clay mineral-22.88, P$_{L}$=0.005 TDS - 0.31 Feldspar ＋ 22.43, e$_{o}$=0.02 Vermiculite - 0.01 Quartz ＋ TDS ＋ 0.93, E$_{50}$=1.94 Vermiculite-0.96 Kaolinite -0.53 silt ＋ 49.64, SR=-0.25 Kaolinite ＋ 1.5 pH - 2.3 Conductivity, CC = 0.03 pH ＋ TDS - 0.2, LL = 0.5 Clay ＋ 1.3 Vermiculite ＋ 5.5 Conductivity ＋ 0.8 Caly mineral-20.4.4.4.4

• 천문학회보
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• 제42권1호
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• pp.58.4-59
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• 2017

Sanduleak's star is a suspected symbiotic binary located in the Large Magellanic Cloud. It is known that it has a giant jet with physical size ~ 14pc. Its spectrum shows two strong emission bands at $6825{\AA}$ and $7082{\AA}$, which are originated from Raman-scattering of O VI by neutral hydrogen atoms. We present the high-resolution spectrum of Sanudleak's star obtained with MIKE at the Magellan-Caly telescope to investigate the O VI emission region based on the profiles of the two Raman features. In this spectrum, it is noted that the Raman $6825{\AA}$ feature exhibits a single broad peak profile, which is in high contrast with a clear triple peak profile of the Raman $7082{\AA}$ feature. In our analysis we suggest that the O VI emission region consist of three main emission parts: an accretion disk, a bipolar outflow and an optically thick, compact component surrounding the white dwarf. By performing Monte Carlo simulation we constrain the representative column density of the H I scattering region N_HI ~1${\times}$10^23 cm^-2, which is in accordance with the observed flux ratio in the two Raman features F(6825)/F(7082) ~ 4.5.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 봄 학술논문 발표대회
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• pp.35-36
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• 2023

Safety management of steel frame members is a very important part to maintain safety and function. However, precise inspection is not possible for steel frame members due to finishing materials and insulation materials, leading to poor inspection. For steel members, an insulating spray coating method is used for high thermal conductivity. The insulation spray method is not only uneconomical, but also has the disadvantage of spoiling the aesthetics. In addition, VOCs are released from paints used in spraying, so a solution is needed. In this study, heating paint was used to improve the disadvantages of the insulation spray coating method and the high thermal conductivity of steel frame members. In addition to this, in order to reduce VOCs generated from the paint, active clay was added to produce a functional exothermic paint, and then the experiment was conducted. As the amount of activated clay increased, the film thickness increased, and the VOCs emission and thermal conductivity decreased.

• 한국지반신소재학회논문집
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• 제8권3호
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• pp.1-7
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• 2009

지오그리드 보강재는 여러 토구조물에 널리 적용되어진다. 일반적으로 보강토 기초의 극한지지력은 강소성이론 이나 한계평형이론에 의하여 설명된다. 강소성이론 이나 한계평형이론에서는 보강재 또는 기초지반에 발생되는 파괴변형이나 변형율에 대하여 정확한 해석을 얻을 수 없다. 본 논문에서는 연약층위의 보강토 기초지반에 대하여 수치해석방법을 이용하여 자세한 파괴변형거동에 대하여 조사하였다. 보강재의 개수, 길이, 깊이 등을 포함하여 연약층위의 보강토 기초에 대하여 일련의 수치해석을 수행하였다. 유한요소프로그램을 사용하여 보강토기초에 대한 파괴거동 및 지지력의 향상효과에 대한 유효성이 조사되었다.

• 한국제4기학회지
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• 제18권2호통권23호
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• pp.3-3
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• 2004

One short core with length of 146cm(HB-107, at coordinates of $N51^{\circ}$11'37.5";$E100^{\circ}$24'45.6", from 229m water depth was subject of the present study. The sub-samples of the core were analyzed for the water contents (WC%), biogenic silica, identification of the main phases, grain size distribution, geochemistry and some physical properties of sediment(Wet density and Magnetic susceptibility) with aims of recording palaeo-environmental changes in Northem Mongolia. The evaluation of the geochemical and mineralogical proxies on palaeo-climated and palaeo-environmental changes are based on comparison to the behvior of biogenic silica through core, as later one had been showed itself, as good indicator of the climate and environmental fluctuation. Age model of the investigating core based on previously C 14 dated core HB105 taken from the central part of the Hobsgol Lake and the result had been published elsewhere. The core consists of two litological varieties : upper diatomaceous silt, lower clay. According to the age model the upper diatomaceous silt formed during the Holocene, lower caly-during the late Pleistocene glacial period. The geochemistry and phase identification analysis on the core samples are resulted in determining main minerals that form the bottom sediments and their geochemistry. The main include quartz, felspar, muscovite, clinochlore, amphibole and carbonate phase(dolomite and calcite). Through the core not only occur the relative quantitative changes of the main phases, but also happen that the carbonate phase completely disappear in diatomaceous silt. This is believed to be related to the lake water salinity changes, which occurred during the trassition period from Pleistocene glacial-to the Holocene interglacial. These abrupt changes of the mineralogy have been clearly traced in geochemistry of sediments, specially in calcium concentration, which is high in lower clay and low in upper diatomaceous silt. That means, geochemistry and mineralogy of the bottom sediments can be used as proxy data on palaeo-climate and palaeo-environmental changes.

• 한국지반공학회논문집
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• 제31권6호
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• pp.15-25
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• 2015

본 연구는 연약지반의 강도증진을 목적으로 친환경 헤어섬유를 혼입한 점토흙의 강도 특성을 파악하였다. 본 연구에서는 헤어섬유의 길이 및 혼입율, 시멘트의 첨가량, 양생기간을 변화시키며 헤어섬유 혼입 점토흙의 압축강도 및 인장강도를 조사하였으며, 또한 응력-변형율 특성을 조사하였다. 시험결과, 헤어섬유 혼입점토는 압축 및 인장 모두에서 강도증진을 보였으며, 특히 인장강도에서 보다 큰 효과가 있는 것으로 나타났다. 뿐만 아니라, 헤어섬유 혼입점토가 파괴시까지 더 큰 변위를 허용하는 것으로 나타났다. 이와같은 결과를 토대로 향후 점토지반 강도증진을 위해 친환경 재료인 헤어섬유를 실무적으로 활용해도 될 것으로 판단된다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.483-490
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• 2004

Nakdong River Plain and its adjoining sea arc unusually covered by very thick soft clay sediments which were caned Pusan clays, sometimes reaching 40-70m. Since early 1990s a large number of geotechnical investigations have been carried out for land reclamation works in the area, including Busan city and its neighboring cities. Nevertheless, geotechnical engineers have paid little attention to studying geological characteristics on the clays, except some researches related to mineralogy, geo-chemistry, benthic foraminiferal fauna etc. The purpose of reserach is the knowledge of the correlation between engineering properties and mineralogy of clay sediments. The correlation analysis carry out multiple regression that have independent variables (Engineering properties) and dependent variables (mineralogy, geochemistry). Engineering properties of clay are correlated with the mineral compositions and geochemical characteristics. The result of the analysis is Wn = -0,6Feldspar + 1.1pH + 0.01TDS + 27.5, Ip = 0.36Clay + 1.44Vermiculite + 0.94clay mineral - 22.118, PI. = 0.005TDS - 0.31Feldspar + 22.43, eo = 0.02Vermiculite - 0.01Quartz + TDS + 0.93, ${\nu}$t = 0.009Quartz - 0.06Conductivity + 1.67, E50 = 1.94Vermicuhte - 0.96Kaohnite -0.53silt + 49.64, SR = -0.25Kaolinite + 1.5pH -2.3Conductivity, Cc = 0.03pH + TDS -0.2, LL = 0.5Clay + 1.3Vermiculite + 5.5Conductivity + 0.8Caly mineral -20.48

• 한국농공학회지
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• 제38권6호
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• pp.83-95
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• 1996

The normal cement concrete is widely used material to build the construction recently, but it has a fault to increase the dead load on account of its unit weight is large compared with strength. So, main purpose of this study was to establish the physical and mechanical properties of lightweight concrete using expanded polystyrene bead on fine aggregate and natural gravel, expanded clay and pumice stone on coarse aggregate. The test rusults of this study are summarized as follows; 1. The water-cement ratio of concrete using pumice stone was larger than that of the concrete using natural gravel and expanded clay. 2. The unit weights of concrete using pumice stone and expanded caly were shown less than 1,000g/$m^3$. 3. The compressive strengths of all types were shown less than 60kg/$cm^2$, tensile and bending strengths were shown less than l3kg/$cm^2$ and 3lkg/$cm^2$$^2$, respectively. 4. The pulse velocity of concrete was shown similar with using natural gravel and pumice stone, and shown the lowest using pumice stone. 5. The dynamic modulus of elasticity of concrete was shown considerably smaller, and shown the lowest using pumice stone. 6. The static modulus of elasticity of concrete using expanded clay and pumice stone were shown considerably smaller, and shown 22% ~29% as compared with the dynamic modulus of elasticity. 7. The stress-strain curves of concrete were shown similar, generally. And the curves were repeated at short intervals increase and decreased irregularly.

• Elastomers and Composites
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• 제40권2호
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• pp.112-118
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• 2005

실란 커플링제가 카본블랙과 점토로 보강된 천연 고무 가황물의 회복 특성에 미치는 영향에 대해 연구하였다. Bis-(3-(triethoxysilyl)-propyl)-tetrasulfide (TESPT)를 실란 커플링제로 사용하였다. 실란 커플링제가 함유된 가황물은 실란 커플링제가 함유되지 않은 가황물에 비해 전반적으로 빠른 회복 거동을 보였다. 그러나, 점토 함량이 높은 가황물의 경우 $-20^{\circ}C$보다 낮은 온도에서는 실란 커플링제가 함유된 가황물이 실란 커플링제가 함유되지 않은 가황물에 비해 느리게 회복되었다. 실란 커플링제가 함유된 가황물과 실란 커플링제가 함유되지 않은 가황물의 회복량 차이는 점토 함량이 증가할수록 감소하였다. 실험 결과는 가교 밀도, 모둘러스, 그리고 결합 고무량으로 설명하였다.

• 대한토목학회논문집
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• 제42권4호
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• pp.501-508
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• 2022

지하수위 회복을 위한 함양정 운영시 필요 기술은 지반이 파괴에 도달하지 않는 최대 주입압을 결정하는 것이다. 고전적인 토질역학에 기초한 수치해석과 실내시험을 통하여 사질토와 점성토의 항복에 도달하는 최대 주입압력을 추론하였다. 수치해석에서는 주입압력에 따른 점성토의 구속압력 감소에 따른 파괴시, 사질토는 유출동수 경사에 따른 파이핑 발생시 주입압력을 최대 한계압으로 결정하였다. 실내시험에서는 간극수압이 높아지는 것을 배압 증가를 통하여 구현하였으며, 사질토 경우 유효응력이 0이 되기전 최대 배압의 93 %에서 급격한 체적변형이 발생하였다. 점성토의 경우는 유효응력이 0에 도달할 경우 방사방향 변형율이 1.5 %에 도달하였으나 급격한 체적변형이 발생하지 않았다. 따라서 상기 결과에 근거하여 함양정의 최대 주입압력을 수치해석과 실내시험으로 결정할 수 있었다.