• 한국세라믹학회지
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• 제28권12호
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• pp.1012-1018
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• 1991

SiC whisker-reinforced LAS matrix composites were developed by a mixed colloidal processing route. An optimization of processing conditions was made using the zeta potential data of silica, boehmite, and SiC whisker dispersions. Similarly, the SiC whisker-reinforced composites were also fabricated by the conventional sol-gel process using the hydrolysis-condensation reaction of relevant metal alkoxides. The composites fabricated by the mixed colloidal processing route were characterized by a uniform spatial distribution of SiC whisker throughout the matrix. The fracture toughness increased from 1.3 MPa.m1/2 for the LAS specimen to 5.0 Mpa.m1/2 for the hot-pressed composite (95$0^{\circ}C$ and 20 MPa for 20 min) containing 20 wt% SiC whisker. The increase in fracture toughness appears to result mainly from the crack deflection and the crack bridging by whiskers with some additional toughenings from the whisker pullout and the matrix prestressing mechanisms.

• KIEAE Journal
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• 제7권6호
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• pp.73-81
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• 2007

The improvement of the life standard of the public by the economical growth leads their interests to the leisure activities, so that the demand for resort facilities has been increased. Especially, casino resort facilities in Kangwon-Do has been developed continuously without exact concept of casino resort design. This resort facilities has been planned by indiscreet imitation of foreign examples and non-organized developments and etc. One of the reasons for these problems may be from the lack of the knowledges and researches related to the architectural approaching of these facilities. The purpose of this study is to provide the basic informations for better understanding and improvement of planning and design direction for these facilities through a survey the famous casino resort facilities in Las Vegas. As a result of this research, Las Vegas has been changed tremendously from the casino resort to the resort complex for families with special theme and various facilities.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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• pp.679-684
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• 2002

MODIS LAI has been one of key products for analyzing the quantitative aspects ofterrestrial ecology. This study was designed to validate MODIS LAS product by using the reference LAI map that was derived from both ground measurements and ETM＋ surface reflectance. The study area, the Kwangneung Experiment Forest in Korea, covers mixed species of deciduous and conifers of temperate forest. Throughout the growing season of 2002, we have measured LAS at the 30 sample plots using an optical device. Ground measured LAS data were then correlated to the ETM＋ reflectance to produce a continuous map of LAS over the study area. Preliminary comparison between MODIS LAI and the reference LAI map showed the lower LAI values from the MODIS product.

• Advances in environmental research
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• 제2권3호
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• pp.229-243
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• 2013

Coagulation-flocculation (CF) was tested coupled with an aerobic biofilter to reduce total petroleum hydrocarbon (TPHs) concentration and toxicity from petrochemical wastewater. The efficiency of the process was followed using turbidity and chemical oxygen demand (COD). The biofilter was packed with a basaltic waste (tezontle) and inoculated with a bacterial consortium. Toxicity test were carried out using Lactuca sativa var. capitata seeds. Best results for turbidity removal were obtained using alum. Considerable turbidity removal was obtained when using Opuntia spp. COD removal with alum was 25%, for Opuntia powder it was 36%. The application of the biofilter allowed the removal of 70% of the remaining TPHs after 30 days with a biodegradation rate (BDR) value 47 $mgL^{-1}d^{-1}$. COD removal was slightly higher with BDR value 63 $mgL^{-1}d^{-1}$. TPH kinetics allowed a degradation rate constant equal to $4.05{\times}10^{-2}d^{-1}$. COD removal showed similar trend with $k=4.23{\times}10^{-2}d^{-1}$. Toxicity reduction was also successfully achieved by the combined treatment process.

• 한국식품위생안전성학회지
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• 제8권3호
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• pp.163-169
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• 1993

ICR 마우스를 이용하여 계면 활성제인 LAS-Na 와 MES의 급성 경구독성을 실시하였다. 6주령된 마우스 LAS-Na는 0, 1,000, 1,320, 1,780, 2,280, 3,000 mg/kg의 용량으로 MES는 0, 1,000, 1,560, 2,450, 3,830, 6,000mg/kg의 용량으로 1회 경구 투여한 후 14일간 관찰하였다. 두 물질 모두 관찰 기간동안 대조군에 비하여 유의성 있는 체중변화는 관찰되지 않았다. 시험물질과 관련된 주요 임상증상으로는 설사, 활동성 감소, 입모 등이 관찰되었다. 사체에 대한 부검결과 시험물질에 의한 것으로 판단되는 소장 점막의 충혈이 소수례 관찰되었으며, 생존 동물에서는 특이한 만한 이상소견은 발견되지 않았다. 이상의 결과로부터 $LD_{50}$값은 LAS-Na의 경우 수컷과 암컷에서 각각 1,319 mg/kg, 1,402 mg/kg이었으며, MES의 경우 수컷에서는 2,040 mg/kg, 암컷에서는 2,546 mg/kg으로 산출되었다.

• 한국세라믹학회지
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• 제44권8호
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• pp.451-456
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• 2007

This paper presents results and observations obtained from a study of sintering behavior and crystallization in $Li_2O-Al_2O_3-SiO_2$ (LAS) Glass by screen printing method. The variable experimental conditions were determined carefully by Thermal-Mechanical Analyzer (TMA), Differential Thermal Analyzer (DTA) for setting the optimum transparent sintering conditions in LAS glass system, $10.5Li_2O-14.7Al_2O_3-58.1SiO_2-16.7B_2O_3(wt%)$, such as glass-ceramics which usually have low crystallization temperatures. Crystallization glasses generated during sintering was observed from diffraction patterns by X-Ray Diffraction (XRD), transmittance by UV-Vis spectrometer. Finally, the optimum sintering condition of LAS glass and the relation between factors and results in several sintering conditions were given by using Response Surface Methodology (RSM). From this study, we confirmed that crystallization interrupted densification during glass powder sintering. Furthermore, we observed that main effect of factors in glass powder sintering with concurrent crystallization depended on experimental conditions from main effects plot by MINTAB-14.

• 공업화학
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• 제8권6호
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• pp.881-885
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• 1997

본 연구에서는 유용성 염료인 sudan III를 이용하여 비이온 계면활성제인 GL-12와 범용 음이온 계면활성제인 linear laurylbenzene sulfonate(LAS) 또는 sodium polyoxyethylene(3) glycol lauryl ether sulfate (SLES) 혼합 용액의 가용화력에 대하여 조사하였다. 두 계면활성제 혼합계 (GL-12/LAS, GL-12/SLES)의 가용화력은 각각 계면활성제 혼합비에 크게 영향을 받았으며 GL-12의 함량이 증가할수록 가용화력도 증가 하였다. 용액의 가용화력에 NaCl이 미치는 영향으로부터 GL-12/LAS계에서는 solubilizate인 sudan III가 가용화 후 미셀내 palisade 층 근처에 위치하고 GL-12/SLES 혼합계에서는 solubilizate가 미셀의 core부근에 위치함을 알 수 있었고 이는 LAS와 SLES의 분자구조 차이에 기인한다.

• 농업과학연구
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• 제21권1호
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• pp.60-66
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• 1994

하수 및 토양시료로부터 다수의 LAS분해세균을 분리하고 고농도 (LAS 200ppm)의 액체 배지에서 생육하면서 분해력이 높은 KL-3, SH-2, EN-1등 3개 균주를 선발하였다. 이들의 형태적, 생리적 및 배양적 성질에 따라 KL-3은 Klebsiella속, SH-2는 Shigella속, EN-1은 Enterobacter속 균주로 각각 동정되었다. 실험실용 발효조에서의 LAS의 분해양상은 배양초기에 분해속도가 빠르고 (1 일후의 분해율: KL-3 및 SH-2, 50%; EN-1, 20%), 배양 1-2일사이에서 그 속도가 크게 지연되다가 다시 분해가 빠르게 진행되며 3, 4일후에는 다시 늦어지는 경향을 나타내었다 (7일후의 분해율: KL-3, 85%; SH-2, 82%; EN-1, 75%). 균체의 생육은 배양 2일 후에 $10^8cfu/mL$수준의 정지기에 도달하였으며 pH는 최초 7.0에서 6.2~6.7의 범위로 저하되어 서서히 변화하는 경향이었다. 균체에 의한 LAS의 흡착량은 Shigella sp. SH-2균주의 경우가 가장 많았으며 Freund1ich흡착등식 Y= 0.030X + 0.95를 나타내었다.

• 한국결정성장학회지
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• 제22권1호
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• pp.57-63
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• 2012

$Al_2TiO_5$에 LAS(${\beta}$-spodumene)와 $Fe_2O_3$를 첨가하여 고상법으로 세라믹 소결체를 제조하였다. $Al_2TiO_5$에 첨가된 LAS는 액상을 형성하고, $Fe_2O_3$는 입자 성장을 억제시켜 소결체를 치밀화하였다. 첨가제의 양을 변화시켜 소결특성, 기계적 특성 및 열충격 특성에 대하여 조사하였다. $Fe_2O_3$가 20 wt% 첨가된 LAS를 $Al_2TiO_5$에 20 wt% 첨가하였을 때, 꺽임 강도는 120 MPa 이상이었고, 열충격에 대한 저항성은 $1200^{\circ}C$ 이상으로 우수함을 확인하였다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2007년도 추계학술발표대회 및
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• pp.118.2-118.2
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• 2007