• 한국디지털건축인테리어학회논문집
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• 제12권4호
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• pp.87-95
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• 2012

Autoclaved lightweight concrete (ALC), also known as autoclaved aerated concrete (AAC), is a lightweight, precast building material that simultaneously provides structure, insulation. ALC is a unique building material. Because of its cellular nature, it is lightweight, self-insulating, as well as sound and fireproof. ALC products include blocks, wall panels, floor and roof panels, and lintels. Recently, the use of ALC has became increasingly popular. However, ALC have high water absorption, low compressive strength and popout the origin of the low surface strength in its properties. Thus, this study is to improve the fundamental strength by controls of increasing of admixtures and chemical reactants. Admixtures make use of meta kaolin and silica fume, chemical reactants make use of sodium silicate and sodium hydroxide. From the test result, the ALC using admixtures and chemical reactants have a good fundamental properties compared with plain ALC. These good fundamental properties is caused by the admixtures and chemical reactants of ALC by the reason of the micro filling effect and chemical binding of C-S-H gel, tobermolite and quartz.

• 한국토양비료학회지
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• 제26권1호
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• pp.1-9
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• 1993

경북(慶北) 일부(一部) 지역(地域)에 분포(分布)되어 있는 회색혈암(灰色頁岩)의 잔적층모재(殘積層母材), 붕적층모재(崩積層母材) 및 충적층모재에서 유래(由來)되고 지형적(地形的)으로 연쇄성(連鎖性)이 있는 토양(土壤)(대구통(大邱統), 시예통(詩禮統), 반호통(盤湖統), 비곡통(秘谷統))을 대상(對象)으로 토양점토광물(土壤粘土鑛物)에 대한 광물학적(鑛物學的) 특성(特性)과 생성과정(生成過程)을 구명(究明)하기 위해 모래, 미사(微砂), 점토(粘土)의 화학조성(化學組成), 광물(鑛物)의 분리동정(分離同定) 및 특성변화(特性變化)를 조사(調査)함과 아울러 수산화간층광물(水酸化間層鑛物)(Hydroxy-interlayered Mineral)의 해명(解明)과 특(特)히 점토광물(粘土鑛物)의 정량(定量)을 시도(試圖)하였던 바, 그 결과(結果)를 요약(要約)하면 다음과 같다. 1. 점토광물(粘土鑛物)의 분포(分布)는 표고별(標高別) 모재(母材)의 형태(形態)에 따라 상이(相異)하였으며 주요(主要) 광물(鑛物)은 illite, Vermiculite, Kaolin 광물(鑛物), 그리고 수산화간층광물(水酸化間層鑛物)이며, 부광물(副鑛物)로 혼재(混在)하는 광물(鑛物)은 illite와 Chlorite 또는 Vermiculite의 혼층광물(混層鑛物)과 chlorite였음. 2. 잔적층모재토양(殘積層母材土壤)의 점토광물(粘土鑛物) 분포(分布)에서 시예통(詩禮統)은 Kaolin광물(鑛物) 조성(組成)이 높은 반면 상부(上部)에 위치(位置)하고 토양발달(土壤發達)이 상대적(相對的)으로 낮은 대구통(大邱統)에서는 illite, Vermiculite 및 수산화간층광물(水酸化間層鑛物)의 2:1형(型) 점토광물(粘土鑛物) 분포(分布)가 높았음. 3. 붕적층(崩積層)과 충적층모재 토양(土壤)에서는 illite와 혼층광물(混層鑛物)의 조성(組成)이 높았으며 수산화간층광물(水酸化間層鑛物)의 조성(組成)은 잔적층모재(殘積層母材) 토양(土壤)에 비해 낮았다. 4. 토양점토광물(土壤粘土鑛物)의 생성과정(生成課程)은 대구통(大邱統) ; illite ${\rightarrow}$ vermlculite ${\rightarrow}$ 수산화간층광물(水酸化間層鑛物), 시예통(詩禮統); Vermiculite ${\rightarrow}$ Kaolin 광물(鑛物), 반호통(盤湖統)과 비곡통(秘谷統) ; illite ${\rightarrow}$ illite/Vermiculite 또는 chlorite 혼층광물(混層鑛物) ${\rightarrow}$ Vermiculite의 풍화단계(風化段階)가 우세(優勢)하게 진행(進行)되는 것으로 추정(推定)되었다. 5. 점토광물(粘土鑛物)의 정량분석(定量分析) 결과(結果), vermiculite함량(含量)은 반호통(盤湖統)과 비곡통(秘谷統)(12%), Kaolin광물(鑛物)은 시예통(詩禮統)(18%), 그리고 수산화간층광물(水酸化間層鑛物)은 대구통(大邱統)(22%)에서 높았다.

• 한국지반환경공학회 논문집
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• 제10권4호
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• pp.59-63
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• 2009

본 연구는 지반개량공법에 사용되는 동전기 공법에서 나노섬유를 전극재로 사용하여 지반개량효과 및 나노섬유에 대한 전극재로서의 대체가능성을 확인하였다. 이를 위해 Electrokinetic cell을 제작하여 나노섬유를 PBD에 삽입 후 교반된 Kaolin clay에 전기삼투를 적용한 후 실험전후의 침하량, 함수비, 압밀배수량, 전단강도에 대한 지반개량효과를 비교 분석하였다. 또한 전기삼투실험은 전극거리와 전압경사를 변화시키면서 실험을 수행하였으며, 그 결과로 전압경사증가 및 전극거리가 감소할수록 침하량, 전단강도, 압밀배수량은 증가하였고 함수비는 감소하는 것으로 나타났다. 이는 지반개량을 위한 동전기 적용시 사용되는 전극재의 소재로 나노섬유가 충분한 가능성이 있는 것으로 판단된다.

• Advances in Computational Design
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• 제5권2호
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• pp.195-207
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• 2020

The present study focuses on the application of artificial neural network (ANN) and Multiple linear Regression (MLR) analysis for developing a model to predict the unconfined compressive strength (UCS) and split tensile strength (STS) of the fiber reinforced clay stabilized with grass ash, fly ash and lime. Unconfined compressive strength and Split tensile strength are the nonlinear functions and becomes difficult for developing a predicting model. Artificial neural networks are the efficient tools for predicting models possessing non linearity and are used in the present study along with regression analysis for predicting both UCS and STS. The data required for the model was obtained by systematic experiments performed on only Kaolin clay, clay mixed with varying percentages of fly ash, grass ash, polypropylene fibers and lime as between 10-20%, 1-4%, 0-1.5% and 0-8% respectively. Further, the optimum values of the various stabilizing materials were determined from the experiments. The effect of stabilization is observed by performing compaction tests, split tensile tests and unconfined compression tests. ANN models are trained using the inputs and targets obtained from the experiments. Performance of ANN and Regression analysis is checked with statistical error of correlation coefficient (R) and both the methods predict the UCS and STS values quite well; but it is observed that ANN can predict both the values of UCS as well as STS simultaneously whereas MLR predicts the values separately. It is also observed that only STS values can be predicted efficiently by MLR.

• 한국결정성장학회지
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• 제7권4호
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• pp.626-631
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• 1997

하동고령토($Al_2O_3-SiC-C$)를 출발원료로하여 AlSiCa내화재 원료를 합성하였다. 하동고령토와 탄소분말을 혼합하여 수소분위기하에서 반응시킨결과, $1300^{\circ}C$에서$Al_2O_3-SiC-C$ 복합체가 힙성되기 시작하여$1400^{\circ}C$에서 완전 합성되었고, $SiO_2$에 대한 최적carbon량은 mole비로 1:4이었다. 합성시 알루미나 용기에 탄소분말을 충전시키지 않을 때는 미합성부분이 없이 밝은 녹색을 띈 $\beta$-SiC(cubic form) 를 형성함을 확인하였다.

• 한국세라믹학회지
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• 제54권1호
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• pp.55-60
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• 2017

An anorthite-based traditional ceramic was developed by adding secondary flux materials to a mixture of kaolin and $CaCO_3$ in order to minimize the deformation during the sintering process. Three flux materials, feldspar, talc, and frit, were evaluated by comparison with two commercial chinaware bodies. Anorthite body with glass frit exhibited poor firing shrinkage. Poor mechanical properties (modulus of rupture, MOR < 30 MPa) was observed for the bodies with feldspar. Another anorthite body was formulated with wollastonite as a Ca source. The fired body showed a MOR of 81 MPa and a shrinkage rate of 6% when wollastonite was added up to 50%. In the XRD analysis, the phase ratio between anorthite and quartz was the highest in the specimen with 50% wollastonite addition. Homogeneous and relatively small closed pores were observed in the microstructural analysis. These results suggest that a ceramic body formulated with 50% kaolin and 50% wollastonite can be fired at $1200^{\circ}C$ with a 6% firing shrinkage rate, giving rise to minimal sintering deformation.

• 한국세라믹학회지
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• 제43권5호
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• pp.315-319
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• 2006

There have been some studies on the use of coal waste as a raw material for clay bricks due to the lack of naturally producing minerals. It can help resolving the problems of pollution, forest conservation and flood control by utilizing coal waste. However, high content of carbon materials usually leads to the black core in clay bricks after firing process, and diminishes the mechanical and aesthetical properties of clay brick. In this study, the effect of firing process is investigated for the removal of black core in clay bricks with carbon content. The removal kinetics of black core are also compared and investigated with the firing schedule and black core removal.

• 한국약용작물학회지
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• 제28권2호
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• pp.128-135
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• 2020

Background: Sowing seeds of Adenophora triphylla is known to be difficult owing to their small size and irregular seed shape. Therefore, this study was conducted to develop a seed pelleting technique to save labor during sowing. Methods and Results: To identify the optimal germination temperature for A. triphylla seeds, the temperature range was set from 17℃ to 32℃. Germination surveys were conducted in plastic greenhouse conditions in March, April, and May to determine the appropriate sowing time. The optimal germination temperature for A. triphylla seeds was 29℃ and May was the optimal sowing time in plastic greenhouse conditions. Covering materials for seed pelleting used talc (T), kaolin (K), calcium carbonate (C), and vermiculite (V). The pellet binder used agar (A), pectin, xanthan gum, polyvinyl alcohol (PVA), and sodium alginate (S). The best suited treatment mixture were the best suited in kaolin / calcium carbonate / vermiculite (KCV), talc / calcium carbonate / vermiculite (TCV) mixture treatment for covering material, and sodium alginate (S), agar (A) as pellet binder, respectively. The germination rate was the best in TCV mixed with S. Conclusion: The mixture of TCV (2 : 1 : 3) + 1.5% S (TCVS), was found to be the best pelleting materials for A. triphylla seeds, and seed pelleting can be labor-saving during sowing.

• Nuclear Engineering and Technology
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• 제51권5호
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• pp.1444-1450
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• 2019

The fast-neutron shielding behaviour (FNSB) of two clay-materials (Ball clay and Kaolin)of Southwestern Nigeria ($7.49^{\circ}N$, $4.55^{\circ}E$) have been investigated using effective removal cross section, ${\Sigma}_R(cm^{-1})$, mass removal cross section, ${\Sigma}_{R/{\rho}}(cm^2g^{-1})$ and Mean free path, ${\lambda}$ (cm). These parameters decide neutron shielding behaviour of any material. A computer program - WinNC-Toolkit has been used for computation of these parameters. The toolkit evaluates these parameters by using elemental compositions and densities of samples. The proficiency of WinNC-Toolkit code was probe by using MCNPX and GEANT4 to model fast neutron transmission of the samples under narrow beam geometry, intending to represent the actual experimental setup. Direct calculation of effective removal cross section ($cm^{-1}$) of the samples was also carried out. The results from each of the methods for each types of the studied clay-materials (Ball clay and Kaolin) shows similar trend. The trend might be the fingerprint of water content retained in each of the samples being baked at different temperature. The compositions of each sample have been obtained by Particle-Induced X-ray Emission (PIXE) technique (Tandem Pelletron Accelerator: 1.7 MV, Model 5SDH). The FNSB of the selected clay-materials have been compared with standard concrete. The cognizance of various factors such as availability, thermo-chemical stability and water retaining ability by the clay-samples can be analyzed for efficacy of the material for their FNSB.

• 한국세라믹학회지
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• 제32권1호
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• pp.71-82
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• 1995

The weathered two-mica granite is widely distributed in Korea and called a kind of ground rock for kaolin. The major minerla compositions are consist of this quartz, feldspar, mica and clay mineral. At present, only a small portion of this granite is used as the material for the low-grade tile industry due to the low S.K. value and the high contents of impurities such as Fe2O3 and FeO. The low S.K. value is caused by feldspars not weathered to clay minerals. The refinement of this thus has been required for the recent shortage of the resources of high-grade one. This paper concerns an optimum hydrothermal treatment condition to refine the low-grade weathered two-mica granite of which impurities are feldspar mineral and Fe2O3. FeO components in using for the main material of ceramic industry. And then, from this result, we tried to fine out the basic formation mechanism of clay mineral from feldspar etc and develope the effectual utilization method of this.