• Polymer(Korea)
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• v.31 no.5
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• pp.374-378
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• 2007

Water-soluble terpolymer of acrylamide, diacetone acrylamide, and acrylic acid was prepared by redox initiators in aqueous medium. One component photoresist was synthesized by reaction of terpolymer with 4-azidoaniline. By blending the aqueous acrylamide/diacetone acrylamide copolymer solution with bisazide, 4,4'-diazidostilbene -2,2'-disulfuric acid sodium salt, two component photoresist was prepared. The photosensitivity per azido group unit mole of one component photoresist was 4 times higher than that of two component photoresist. The dot-type pattern was successfully achieved with one component photoresist at low exposure energy, which is prospective to be used as black matrix negative photoresist.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.25 no.3
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• pp.267-275
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• 2012

In this study, crack growth in a center-cracked plate is predicted under mode I variable amplitude loading, and the result is validated by experiment. Huang's model is employed to describe crack growth with acceleration and retardation due to the variable loading effect. Experiment is conducted with Al6016-T6 plate, in which the load is applied, and crack length is measured periodically. Particle Filter algorithm, which is based on the Bayesian approach, is used to estimate model parameters from the experimental data, and predict the crack growth of the future in the probabilistic way. The prediction is validated by the run-to-failure results, from which it is observed that the method predicts well the unique behavior of crack retardation and the more data are used, the closer prediction we get to the actual run-to-failure data.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.2
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• pp.162-165
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• 2002

To determine changes of heme compounds on lipid oxidation during repeat heating in white muscled fish (yellowfin sole and yellow croaker), myoglobin, metmyoglobin, total iron, nonheme iron and heme iron contents were analysed. Myoglobin content was decreased in the step of repeat heating. Especially, it was decreased the most rapidly roasted at 180$^{\circ}C$ for 20 min in fillet samples. The skinless fillet roasted at the lower temperature resulted in the higher level of metmyoglobin associated with the reduced myoglobin. Regardless of roasted temperature and time, total iron content was not change in contrast of raw meat throughout processing. Nonheme iron content was increased, but heme iron content was decreased during roasted, heated and reheated.

• KSBB Journal
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• v.9 no.2
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• pp.133-139
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• 1994

Oligosaccharide formation and the production of transfructosylase and transglucosylase by Aureobasidium pullulans were studied in sucrose or maltose media, respectively. The initial uptake rates of substrate in sucrose-rich media were faster than that in maltose-rich media, also most parts of oligosaccharides formed and other monosaccharides released were utilized progressively as substrate during the cultivation periods. However, when the initial amount of sucrose was raised to $100g/\ell$, high concentration of monosaccharides were liberated, consequently high-level fructose was accumulated unused during fermentation. The biggest molecule of oligosaccharide synthesized was hexasaccharide in all cultivation media examined, of which the organism could not utilize isomalto-oligosaccharide of DP6 synthesized in a maltose-rich medium. The maximum amount of oligosaccharides produced was $58g/\ell$ when $100g/\ell$ of sucrose and $5g/\ell$ of maltose were used as initial substrate. From the early stage of growth both fructooligosaccharides and isomalto-oligosaccharides were synthesized and progressively utilized as substrates during the fermentation. Based on the experimental results, it was suggested that maltose could induce both transfructosylase and transg1ucosylase, whereas sucrose was unable to slimulate transglucosylase formation.

• Spatial Information Research
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• v.19 no.2
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• pp.37-46
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• 2011

Recently in the field of GIS(Geographic Information System), data integration from various sources has become an important topic in order to use spatial data effectively. In general, the integration of spatial data is accomplished by navigating corresponding space object and combining the information interacting with each object. But it is very difficult to navigate an object which has correspondence with one in another dataset. Many matching methods have been studied for navigating spatial object. The purpose of this paper is development of method for searching correspondent spatial object considering local position error which is remained even after coordinate transform ation when two different building data sets integrated. To achieve this goal, we performed coordinate transformation and overlapped two data sets and generated blocks which have similar position error. We matched building objects within each block using similarity and ICP algorithm. Finally, we tested this method in the aspect of applicability.

• Restorative Dentistry and Endodontics
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• v.25 no.1
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• pp.133-143
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• 2000

목 적: 통상적인 근관성형 과정에서 근관형태의 직선화 경향을 발견할수 있으며 그 결과 만곡이 심한 근관에서 이상적인 근관 형태를 얻기가 어려움으로 인해 이를 극복하기 위한 많은 기구들과 근관 성형법들이 개선되었고 소개되었다. 본 연구에서는 수통형 Stainless Steel K-file, Niti 엔진 구동형 Profile .04와 Quantec LX file를 이용하여 만곡 근관의 성형 후 최종 근관 형태를 비교하고 평가하고자 한다. 방 법: 본 실험은 Bramante등의 방법을 변형하여 술 전의 근관 형태와 술 후의 근관 형태를 비교하였다. Schneider의 방법에 따라 $12^{\circ}$에서 $68^{\circ}$ 이내에 만독도를 가진 45개의 발거된 상하악 대구치의 근심근관들을 선택하여 15개씩 3개의 군으로 나누고 알루미늄으로 제작된 mold에 투명한 교정용 레진으로 매몰하였다. 근첨에서 2.5, 5, 8mm 지점에서 절단하고 각 mold에 재조립한 후 다음과 같이 근관 성형을 시행하였다. 제 1 군은 SS K-file를 이용하여 Step-back 방법; 제 2 군은 NiTi 엔진 구동형인 Profile .04 ; 제 3 군은 NiTi 엔진 구동형인 Quantec LX file로 근관 성형하였다. 술 전과 술 후에, 각 시편들을 입체 현미경으로 사진 촬영하여 근관 중심 위치 이동률, 근관성형 후 면적과 모양, 잔존 상아질의 최 소 두께를 Sigma scan / image software program으로 계산하고 One way ANOVA로 통계적 유의성을 검증하였다. 결 론: 1. Profile .04와 Quantec LX는 SS K-file보다 근관성형시 근관의 본 형태를 유지하는 경향이 있었으나 통계적으로 유의성이 없었다(p>0.05). 2. 근관 성형 후 면적은 Profile .04 엔진 구동형 NiTi file를 이용한 군이 다른 군과 비해 가장 적었으나 통계적으로 유의성이 없었다(p>0.05). 2. 모든 방법들은 같은 부위에서 같은 방향으로 전이되는 양상을 보였다. 즉, 근단부에서는 바깥쪽으로, 중앙부에서는 안쪽으로 전이하려는 경향이 있었다. 그러나, 치관부에는 그러한 법칙이 적용되지 않아 전이되는 양상이 안쪽이나 바깥쪽으로 구별되지 않게 일어났다. 3. 술 후에 근관의 모양은 원형, 타원형, 불균일한 형태들이 다양하게 나타났지만, Profile .04와 Quantec LX를 사용했을 때 주로 원형 형태의 근관을 보여주었으며 Stainless Steel K-file은 타원형이나 불균일한 근관 형태를 보였다.

• Membrane Journal
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• v.15 no.1
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• pp.15-21
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• 2005

The integrally skinned asymmetric PAN ultrafiltration membranes were annealed for reducing the pore size. The effect of the chemical structure of two PAN polymers (homo- and copolymer) on annealing was investigated. The annealing of PAN polymer was strongly affected by the chemical structure of the polymer. In other words, the annealing effect of the copolymer was much larger than that of the homopolymer due to its less rigid structure of the main chain. Before annealing, the membranes were usually preheated in water in terms of the complete removal of remained solvents in the membranes. The annealing effect was bigger when no preheating. However, the preheating of the membrane before annealing at high temperatures leads to an increase in the pore size of membranes. The surface of the membranes was slightly negative and the salt rejection of PAN nanofiltration membrane was in the following order: R(Na₂SO₄) > R(NaCl) > R(MgSO₄) > R(CaCl₂). This salt rejection behavior could be explained by the Donnan equilibrium and the electroneutrality.

• Applied Chemistry for Engineering
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• v.19 no.3
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• pp.332-337
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• 2008

Hydrosilylation reaction of 1,1,1,3,5,5,5-heptamethyl trisiloxane (HMTS) and unsaturated poly(oxyethylene) (UPOE) was carried out in the presence of Speier's catalyst. The effect of molar ratio of two reagents on the reactivity and the structure of the product (HMTS-POE) were investigated by FT-IR and $^1H-NMR$. The pure HMTS-POE without containing unreacted HMTS or UPOE could be obtained by the reaction with excess amount of HMTS and followed by removing unreacted HMTS under vacuum. Under the same reaction conditions, various HMTS-POEs composed of UPOEs with a different molecular weight were synthesized, and the surface tensions of HMTS-POEs were analyzed. HMTS-POE, whose EO contents are in the range of 49~57%, exhibited lower surface tension and a potential application for low molecular weight silicone modified with polyethers.

• Resources Recycling
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• v.21 no.1
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• pp.41-48
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• 2012

A study on the behavior of boron extraction by TMPD(2,2,4-trimethyl-1,3-pentanediol) was carried out to find the optimum conditions for the boron extraction from brine. In case of boron extraction from 0.736 g/L boron-containing brine, typical optimum extractive conditions would be confirmed to be 0.75 mol/L of extractant concentration at 3.0 pH of brine with 1 of phase ratio and 20 min. of shaking time at 298 K respectively. And 1 mol/L sodium hydroxide of stripping agent was shown above 99 % of boron extraction and stripping efficiencies. Also, extraction equilibrium equation were obtained through experiments as follows : log D = 1.7 log $[TMPD]_O$ + constant at pH < 6.

• Journal of the Korean Applied Science and Technology
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• v.38 no.4
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• pp.1010-1019
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• 2021

Petroleum oil in reservoir has been acquired by primary, secondary and tertiary oil recoveries. Microbial enhanced oil recovery (MEOR) classified to tertiary oil recovery has been evaluated in two ways of in-situ and ex-situ options. In-situ MEOR injects microbes into a depleted oil reservoir and stimulates those to generate metabolites. Among metabolites, biosurfactants play an important role to make heavy residues flow. Ex-situ MEOR injects microbial metabolites instead of microbes into a reservoir to recover oil. Even though both in-situ MEOR and ex-situ MEOR are eco-friend processes, in-situ MEOR can be preferred because it is more economic. Even though MEOR have been evaluated for a long time, it is still in the state of evaluating in a pilot-scale. Among microbes, bacteria have been widely evaluated in MEOR purpose. In this paper, bacteria for MEOR were summarized and their metabolites were qualitatively evaluated.