• 한국미생물·생명공학회지
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• 제23권5호
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• pp.580-587
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• 1995

In order to produce the bacteriolytic enzyme, bacterial strains capable of excreting a large amount of the enzyme were screened from the coastal sea water samples in Pusan. The bacterial strain SH-1, which showed the highest activity among 43 bacteriolytic enzyme producing bacteria, was finally selected for further studies. The strain SH-1 was an endospore-forming grampositive rod, and the position of spore was paracentral. These morphological characteristics assigned the isolated strain to the morphological group I classified by Gordon. The fatty acid composition of the bacterial stain was analyzed to be consisted of branched chains of iso-Cn and anteiso-Cn. Based on the percent content of the branched chain (93.85%), the isolates could be identified as a species of Bacillus. According to the experimental results of the API system (API 50CHB & API 20E) the strain was identified as Bacillus subtilis. Numerical texonomy, in which 82 major characters were examined using several species of Bacillus as the standard bacteria, indicated that the strain SH-1 showed 90% similarity to Bacillus subtilis. Thus, the isolated strain SH-1 could be identified as Bacillus subtilis.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.406.3-407
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• 2002

Analysis of interferon alpha (IFN) modified with high molecular weight branched PEG was performed by capillary electrophoresis (CE) and MALDI-TOF mass spectrometry (MALDI-TOF MS). IFN was modified by the reaction of amine residues with an active ester of monomethoxy polyethylene glycol at various molar ratios. As a CE method. capilary electrophoresis sodium dodecyl sulfate nongel sieving (CE-SDS NGS) was performed using an uncoated capilary filled with a hydrophilic replaceable polymer network matrix. (omitted)

• JSTS:Journal of Semiconductor Technology and Science
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• 제2권4호
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• pp.280-287
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• 2002

We present technical issues involved in the development of actuators and sensors for applications to high-precision Micro Electro Mechanical System (MEMS). The technical issues include fabrication uncertainty and noise disturbance, causing major difficulties for MEMS to achieve high-precision actuation and detection functions. For nano-precision actuators, we solve the fabrication instability and electrical noise problems using digital actuators coupled with nonlinear mechanical modulators. For the high-precision capacitive sensors, we present a branched finger electrodes using high-amplitude anti-phase sensing signals. We also demonstrate the potential applications of the nanoactuators and nanodetectors to high-precision positioning MEMS.

• Korea-Australia Rheology Journal
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• 제11권4호
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• pp.293-304
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• 1999

Refinements of classical theories for entangled or crosslinked polymeric systems have led to incommensurable models for rubber networks and polymer melts, contrary to experimental evidence, which suggests a great deal of similarity. Uniaxial elongation and compression data of linear and branched polymer melts as well as of crosslinked rubbers were analyzed with respect to their nonlinear strain measure. This was found to be the result of two contributions: (1) affine orientation of network strands, and (2) isotropic strand extension. Network strand extension is caused by an increasing restriction of lateral movement of polymer chains due to deformation, and is modelled by a molecular stress function which in the tube concept of Doi and Edwards is the inverse of the relative tube diameter. Up to moderate strains, $f^2$ is found to be linear in the average stretch for melts as well as for rubbers, which corresponds to a constant tube volume. At large strains, rubbers show maximum extensibility, while melts show maximum molecular tension. This maximum value of the molecular stress function governs the ultimate magnitude of the strain-hardening effect of linear and long-chain branched polymer melts in extensional flows.

• Food Science and Biotechnology
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• 제14권2호
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• pp.301-303
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• 2005

State diagram of highly concentrated branched oligosaccharides (HBOS) was constructed to better understand phase behavior of mixtures with different size of oligosaccharides. It showed dramatic plasticizing effect on glass transition, which was successfully described based on Couchman-Karasz equation model. $T_g$' estimated from state diagram corresponded well with previous empirical data measured by maximum ice formation through isothermal holding (annealing) process. Estimated $T_g$' and $C_g$' values were $-36.3^{\circ}C$ and 79.99%, respectively. $T_g$' value of HBOS was approximately $10^{\circ}C$ higher than that of sucrose, while $C_g$' value was similar to those of general carbohydrate materials, which could be useful for applications in frozen system.

• 대한음성학회지:말소리
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• 제42호
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• pp.57-69
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• 2001

Syntactic ambiguity can be understood by context usually, especially in reading and writing. Because phonological structure including stress, intonation and phonological phenomena can be pronounced differently according to different syntactic structures, syntactic ambiguity can be solved by phonological structure in listening and speaking. The objectives of this study was to survey how Korean English teachers apply phonological structures in order to solve syntactic ambiguity. The results of this study is as follows: First, Korean English leachers applied Compound Stress Rules well, when the second word was not branched. But they did not apply Compound Stress Rules well, when the second word was branched. Second, several Korean English teachers did not apply Nuclear Stress Rules well. They usually put the strongest stress on the first word. Third Korean English teachers did not differentiate appropriate applying situation of palatalization. They applied palatalization at both the single and the separated Phonological Phrase. Fourth, Korean English teachers did not apply stress shifting when stress crash happened. Because they did not apply stress shifting, they put the strongest stress on inappropriate syllable.

• BMB Reports
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• 제31권1호
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• pp.37-43
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• 1998

The catabolic ${\alpha}$-acetolactate synthase was purified to homogeneity from Serratia marcescens ATCC 25419 using ammonium sulfate fractionation, DEAE-Sepharose, Phenyl-Sepharose, and Hydroxylapatite column chromatography. The native molecular weight of the enzyme was approximately 150 kDa and composed of two identical subunits with molecular weights of 64 kDa each. The N-terminal amino acid sequence of the enzyme was determined to be Ala-Gln-Glu-Lys-Thr-Gly-Asn-Asp-Trp-Gln-His-Gly-Ala-Asp-Leu-Val-Val-Lys-Asn-Leu. It was not inhibited by the branched chain amino acids and sulfometuron methyl herbicide. The optimum pH of the enzyme was around pH 5.5 and the pI value was 6.1. The catabolic ${\alpha}$-acetolactate synthase showed weak immunological relationships with recombinant tobacco ALS, barley ALS, and the valine-sensitive ALS isozyme from Serratia marcescens.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집A
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• pp.182-187
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• 2000

The application of fracture mechanics have traditionally concentrated on cracks leaded by tensile stresses, and growing under an opening or mode I mechanism. However, many cases of failures occur from growth of cracks subjected to mixed mode loading. Several criteria have been proposed regarding the crack growth direction under mixed mode loadings. This paper is aimed at prediction of fatigue crack growth behaviour under mixed mode(I+II) in two dimensional branched type precrack. In this paper, the maximum tangential stress(MTS) criterion was used to predict crack growth direction. Not only experiment but also finite element analysis(FEA) was carried out. The theoretical predictions were compared with experimental results in this paper

• 대한기계학회논문집
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• 제10권2호
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• pp.257-264
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• 1986

무한평판에 묻혀진 크랙에 대한 응력확대계수를 결정하는 전위분포법을 반무한 평판에서의 표면크랙에 확장 적용하였다. 이를 위해 반평면에서의 전위응력의 기본 해가 간단한 복소수 응력함수형태로 얻어졌다. 평형을 이루는 절편적인 분포로부터 응력확대의 계수를 계산하는 새로운 방식을 제안하였으며, 수직표면 크랙과 묻혀진 경사크랙에 대한 기존해와 이 방법의 결과가 상호 비교되었다. 경사진 표면크랙에 대한 계산결과는 유한평판에서의 기존하는 Mapping Collocation 해석과 비교되어 좋은 일치를 보여 주었다. 구부러진 크랙과 대칭으로 가지친 크랙에 대해서는 표면크랙과 묻혀진 크랙사이에 상당한 차이가 있음이 나타났다.

• Bulletin of the Korean Chemical Society
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• 제26권10호
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• pp.1520-1524
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• 2005

This paper describes the racemic and stereoselective synthetic route for a novel 4'$\alpha$-phenyl and 6'$\alpha$-methyl doubly branched carbocyclic nucleosides from an acyclic 2-hydroxy acetophenone. The installation of phenyl group at the 4'-position of carbocyclic nucleoside was successfully accomplished via a sequential [3,3]-sigmatropic rearrangement. The stereoselective introduction of a methyl group in the 6'$\alpha$-position was accomplished by Felkin-Anh controlled alkylation. Bis-vinyl 11 compound was successfully cyclized using a Grubbs’ catalyst II to desired carbocycles. The natural bases (adenine and cytosine) were efficiently coupled using a Pd(0) catalyst. Although all the synthesized compounds were examined for their activity against several viruses such as HIV-1, HSV-1, HSV-2 and HCMV, only cytosine analogues 17 exhibited weak antiviral activity against HCMV.