• Title/Summary/Keyword: $K_s$

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Study on the Solubilization of Phenoxide Anion into Aqueous Micellar Systems of Cationic Surfactants (양이온 계면활성제에 의한 Phenoxide 음이온의 가용화에 대한 연구)

  • Lee, Byung Hwan
    • Journal of the Korean Chemical Society
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    • v.42 no.4
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    • pp.383-390
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    • 1998
  • The interaction of phenoxide anion with several cationic surfactant micelles (DTAB, TTAB, CTAB, CDEAB, and CTAC) was studied by UV/Vis spectrophotometric method. The solubilization constants of phenoxide anion into the cationic micellar phase and the critical micelle concentration of these surfactants in the presence of the phenoxide anion could be determined from the absorbance changes. The measured solubilization constants were changed according to the following order: $K_s(CTAC)>K_s(CDEAB)>K_s(CTAB)>K_s(TTAB)>K_s(DTAB).$ Effects of salts(NaCl and NaBr) and n-alcohols(butanol, pentanol, and hexanol) on the solubilization of phenoxide anion by the TTAB system have been also measured and analyzed. There was a great decrease of solubilization constant and CMC with these additives. The standard Gibbs free energy, enthalpy, and entropy changes for the solubilization of phenoxide anion by the TTAB system were calculated from the temperature dependence of $K_s$ values.

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A CONSTRUCTION OF TWO-WEIGHT CODES AND ITS APPLICATIONS

  • Cheon, Eun Ju;Kageyama, Yuuki;Kim, Seon Jeong;Lee, Namyong;Maruta, Tatsuya
    • Bulletin of the Korean Mathematical Society
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    • v.54 no.3
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    • pp.731-736
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    • 2017
  • It is well-known that there exists a constant-weight $[s{\theta}_{k-1},k,sq^{k-1}]_q$ code for any positive integer s, which is an s-fold simplex code, where ${\theta}_j=(q^{j+1}-1)/(q-1)$. This gives an upper bound $n_q(k,sq^{k-1}+d){\leq}s{\theta}_{k-1}+n_q(k,d)$ for any positive integer d, where $n_q(k,d)$ is the minimum length n for which an $[n,k,d]_q$ code exists. We construct a two-weight $[s{\theta}_{k-1}+1,k,sq^{k-1}]_q$ code for $1{\leq}s{\leq}k-3$, which gives a better upper bound $n_q(k,sq^{k-1}+d){\leq}s{\theta}_{k-1}+1+n_q(k-1,d)$ for $1{\leq}d{\leq}q^s$. As another application, we prove that $n_q(5,d)={\sum_{i=0}^{4}}{\lceil}d/q^i{\rceil}$ for $q^4+1{\leq}d{\leq}q^4+q$ for any prime power q.

Species-Specific Cleavage by RNase E-Like Enzymes in 5S rRNA Maturation

  • RYOU SANG-MI;KIM JONG-MYUNG;YEOM JI-HYUN;KIM HYUN-LI;GO HA-YOUNG;SHIN EUN-KYOUNG;LEE KANGSEOK
    • Journal of Microbiology and Biotechnology
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    • v.15 no.5
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    • pp.1100-1105
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    • 2005
  • Previous work has identified a Streptomyces coelicolor gene, rns, encoding a 140 kDa protein (RNase ES) that exhibits the endoribonucleolytic cleavage specificity characteristic of RNase E and confers viability on and allows the propagation of E. coli cells lacking RNase E. Here, we identify a putative S. coelicolor 9S rRNA sequence and sites cleaved by RNase ES. The cleavage of the S. coelicolor 9S rRNA transcript by RNase ES resulted in a 5S rRNA precursor (p5S) that had four and two additional nucleotides at the 5' end and 3' ends of the mature 5S rRNA, respectively. However, despite the similarities between RNase E and RNase ES, these enzymes could accurately process 9S rRNA from just their own bacteria, indicating that these ancient enzymes and the rRNA segments that they attack appear to have co-evolved.

Hereditary protein S deficiency presenting acute pulmonary embolism

  • Kim, Jiwan;Kim, Sung Hea;Jung, Sang Man;Park, Sooyoun;Yu, HyungMin;An, Sanghee;Kang, Seonghui;Kim, Hyun-Joong
    • Journal of Yeungnam Medical Science
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    • v.31 no.1
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    • pp.52-55
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    • 2014
  • Protein S deficiency is one of the several risk factors for thrombophilia and can cause blood clotting disorders such as deep vein thrombosis and pulmonary embolism. A 54-year-old man was admitted with the complaint of dyspnea and was diagnosed with pulmonary embolism. The patient had very low level of free protein S, total protein S antigen, and protein S activity (type I protein S deficiency). In history taking, we found that his mother, 78 year old, had a history of same disease 10 years ago, and confirmed the pronounced low level of protein S. The patient's son also had very low level of protein S, however there had not been any history of pulmonary embolism yet. This case study suggests that asymptomatic persons with a family history of protein S deficiency and pulmonary embolism should be checked regularly for early detection of the disease, as protein S deficiency can be suspected.

Fabrication and Characteristics of the Combination Surge Generator (조합형 써지전압.전류발생기의 제작과 특성)

  • Chang, S.H.;Lee, B.H.;Kil, K.S.;Lee, Y.K.;Lee, B.K.;Ohk, Y.H.
    • Proceedings of the KIEE Conference
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    • 1996.07c
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    • pp.1876-1878
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    • 1996
  • This paper describes the combination surge generator for applying performance tests of surge protective devices. The $8/20{\mu}s$ waveform applies to low impedance circuits and components and is commonly used to determine the characteristics of surge protective devices. And the $1.2/50{\mu}s$ waveform applies to high impedance circuits and components and is used for testing dielectric behavior. Therefore, the combination surge generator, which generates $1.2/50{\mu}s$ voltage waveform under open-circuit conditions and $8/20{\mu}s$ current waveform under short-circuit condition, was proposed. Also this generator can produce $10/1000{\mu}s$ as well as $0.5{\mu}s/100kHz$ ring waveform.

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