• Title/Summary/Keyword: $P-{\Delta}$ effect

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Purification and Characterization of the N-terminally Truncated DNA Polymerase from Thermus thermophilus HJ6 (Thermus thermophilus HJ6 유래 N-말단 결실 DNA Polymerase의 정제 및 특성)

  • Jeon, Sung-Jong;Seo, Min-Ho
    • Microbiology and Biotechnology Letters
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    • v.38 no.2
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    • pp.158-162
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    • 2010
  • The gene encoding N-terminally truncated Tod polymerase ($\Delta$Tod polymerase) from Thermus thermophilus HJ6 was expressed in Escherichia coli under the control of the lambda pR and pL tandem promoters on the expression vector pJLA503. The N-terminal domain (250 amino acids) of Tod polymerase was removed without significant effect on enzyme activity and stability, while no 5'$\rightarrow$3' exonuclease activity was detected. The $\Delta$Tod polymerase was verified to possess very efficient reverse transcriptase (RT) activity in the presence of $MgCl_2$. The cDNA can also be amplified in the polymerase chain reaction (PCR) with this mutant enzyme. The $\Delta$Tod polymerase was exhibited higher activity than the Taq polymerase in a one-step RT-PCR.

Hall Effect of High $T_{c}$ superconductor $Y_{1}Ba_{2}Cu_{3}O_{7-\delta}$ Thin Film (고온초전도체 $Y_{1}Ba_{2}Cu_{3}O_{7-\delta}$ 박막의 Hall 효과)

  • 허재호;류제천;김형국;김장환
    • Journal of the Korean Magnetics Society
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    • v.4 no.1
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    • pp.44-47
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    • 1994
  • High $T_{c}$ superconducting $Y_{1}Ba_{2}Cu_{3}O_{7-\delta}$ thin film was grown up for c-axis orientation by epitaxial growth method on $LaAlO_{3}$ single crystal substrate. The crystal structures of this thin film were found to be c-axis orientation by X-ray diffraction patterns. Hall effect and resistivity measurements were made by van der Pauw method. Hall resistivity was calculated from the magnetoresistivity by considering thermomagnetic effect. The relation was $pH=p_{s}tan{\alpha}_{n}-QBT\frac{S_s}{K_s}$ The measured Hall resistivity and the calculated one are in good agreement each other.

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Spacing Effect of the Intervening Sequences between Ribosome Binding Site and the Initiation Codon on Expression of Bacillus thuringiensis $\delta$-Endotoxin

  • Roh, Jong-Yul;Li, Ming-Shun;Chang, Jin-Hee;Park, Jae-Young;Shim, Hee-Jin;Woo, Soo-Dong;Boo, Kyung-Saeng;Je, Yeon-Ho
    • International Journal of Industrial Entomology and Biomaterials
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    • v.6 no.1
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    • pp.81-85
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    • 2003
  • To verify importance of the intervening sequence between the ribosome binding site (RBS) and the initiation codon for expression of Bacillus thuringiensis $\delta$-endotoxin, the pProMu, containing SphI and NcoIsites between RBS and the initiation codon of the cry1Ac gene, and the deletion derivatives of pProMu were constructed and transformed into the B. thuringiensis subsp. kurstaki $Cry^{-B}$ strain. The pProMu-ΔSphIhad identical six bases of intervening sequence to pProAc though the arrangement of sequence was different. Other mutants containing pProMu had 1 or 10 or 14 bases between RBS and the initiation codon. Among deletion mutants, only ProMu-ΔSphI/CB only produced 130 kDa typical bipyramidal crystals like those seen for ProAc/CB. However, ProMu/CB, $ProMu-{\Delta}NcoI$, and ProMu-ΔSphI+NcoIdid not produce Cry1Ac crystals. In conclusion, the results suggest that 6-base intervening sequence was important for expression of cry1-type class gene. Furthermore, spacing effect of the intervening sequences may play an important role in expression of individual crystal proteins in B. thuringiensis without doubt.

Ultimate Resisting Capacity of RC Columns Considering P-$\Delta$ Effect (P-$\Delta$ 효과를 고려한 RC 기둥의 극한저항력 산정)

  • 곽효경;김진국;김한수
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.15 no.1
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    • pp.105-116
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    • 2002
  • In this paper, an analytical model to predict the resisting capacity of slender RC columns is introduced. Material and geometric nonlinearities are taken into account, and the layer approach is adopted to simulate the different material properties across the sectional depth. On the basis of the obtained numerical analysis results, an improved design equation as a function of concrete strength, slenderness ratio, steel ratio and eccentricity for slender RC columns, which can be used effectively in the preliminary design stage, is introduced. Finally, P-M interaction diagrams constructed by the introduced equation are compared with the ACI method with the objective of establishing the relative efficiencies of the introduced equation.

Effect of Solvent on the Dispersion Stability of CaCO3 Pigment (CaCO3 안료의 분산 안정성에 대한 용제의 영향)

  • Lee, Gun Dae;Ryu, Young Cheal;Suh, Cha Soo;Hong, Seong Soo;Ahn, Byung Hyun;Moon, Myung Jun
    • Applied Chemistry for Engineering
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    • v.8 no.2
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    • pp.252-261
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    • 1997
  • The effect of solvent on the dispersion stability of $CaCO_3$ pigment in various solvents and resin solutions has been studied using Dynometer. Dispersion stability can be estimated in a relatively short time by means of Dynometer and the solubility parameter, ${\delta}$, of $CaCO_3$ determined from dispersion stability was 11.62(${\delta}_d=8.04$, ${\delta}_p=5.05$, ${\delta}_h=6.70$). The solvent showing weaker interaction with pigment increased the adsorption of resin on to the pigment, resulting in higher dispersion stability in resin solution. It was found that the rheological properties and dispersion stability of pigmented resin solution were depending strongly on the solvent added in small amount in the formulation.

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The effect of fluoridation on discoloring of bleached teeth (불소 도포가 미백 처리된 치아의 색변화에 미치는 영향)

  • Jang, Hyang-Ah;Suh, Kyu-Won;Ryu, Jae-Jun
    • The Journal of Korean Academy of Prosthodontics
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    • v.47 no.3
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    • pp.257-265
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    • 2009
  • Statement of problem & Purpose: To study the effect of different fluoridation methods after in-office bleaching on the color of teeth during severe staining with coffee. Material and methods: 44 specimens were randomly divided into four groups. Group 1 (no bleaching, no fluoride, coffee) was served as control for the influence of coffee on the color of untreated teeth. Group 2, 3 and 4 were undergone bleaching with 35% $H_2O_2$ for 30 minutes a day on 3 consecutive days. Group 2 was remained without fluoridation. Group 3 and 4 were fluoridated for 1 hour with either Cavity shield$^{(R)}$ or pH 7 Gel$^{(R)}$. All of groups were immersed in coffee solution for 7 days. Color determination was accomplished using the spectrophotometer (VITA Easyshade$^{(R)}$). Results: ${\Delta}L$ and ${\Delta}h$ increased, whereas ${\Delta}C$ decreased in the bleached groups. Pairwise comparisons with Tukey's HSD showed that there were statistically significant differences for ${\Delta}L$ and ${\Delta}h$ between the bleached groups and the non-bleached group (P < .05). ${\Delta}L$ and ${\Delta}h$ decreased continuously, while ${\Delta}C$ showed an increase after a decrease in all of groups during immersion in coffee solution. After immersion in coffee solution for 7 days there were no statistically significant differences for ${\Delta}L$, ${\Delta}C$ and ${\Delta}h$ between the groups (P > .05). Also there were no statistically significant differences for ${\Delta}L$, ${\Delta}C$ and ${\Delta}h$ between the group 3 treated with Cavity shield. and the group 4 treated with pH 7 Gel. (P > .05). Conclusion: It was concluded that fluoridation was not beneficial to the prevention of extrinsic stains after bleaching.

An Analytical Study on Semi-Rigid Connections of 20-Story Braced Steel Structures (20층 가새 철골구조물의 반강접 접합부에 관한 해석적 연구)

  • Kang, Suk-Bong;Kim, Jin-Hyoung
    • Journal of Korean Society of Steel Construction
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    • v.12 no.1 s.44
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    • pp.1-8
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    • 2000
  • In this study, the effect of semi-rigid connections on the structural behavior of 20-story braced steel structure has been investigated utilizing the second-order elastic structural analysis program in which nonlinear behavior of beam-column connections and geometric nonlinearity have been considered. Global effects such as P-delta effect and sway at the top have been studied, as well as distribution of member force and combined stress in structural members as local effects. When the structure subjected to horizontal load and vertical load is equipped with lateral-load resisting system such as braces, replacement of shear connection with semi-rigid connection has not caused any problem in P-delta effect and top lateral displacement. Distribution of member forces resulted in reduction in member size for economic structural design.

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A Study on the Similitude of member Behavior for Small-Scale Modeling of Reinforced Concrete Structure (철근콘크리트 축소모델의 부재거동 상사성에 관한 연구)

  • 이한선;장진혁
    • Magazine of the Korea Concrete Institute
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    • v.8 no.3
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    • pp.177-185
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    • 1996
  • Four types of experiments were performed to check the similitude of member behavior between prototype and 1 /10 scale models : (1) Test of slender columns with P-$\Delta$ effect, (2) Test of short columns with and without confinement steel, (3) Test of simple beams without stirrups, and (4) 'T-beam test. Based on the results of experiments, the conclusions were made as follows : (1) The P-$\Delta$ effect of slender columns can be almost exactly represented by 1/10 scale model. (2) The effect of confinement on short columns by the hoop steel can be also roughly simulated by 1/10 scale model. (3) The failure modes of simple beams without stirrups are brittle shear failures in prototype whereas those of 1/10 scale models are the ductile yielding of tension steel followed by large diagonal tension cracking and compressive concrete failure. (4) The behaviors of prototype and 1/10 scale model in T-beams appear very similar.

Low-frequency Noise Characteristics of Si0.8Ge0.2 pMOSFET Depending upon Channel Structures and Bias Conditions (채널구조와 바이어스 조건에 따른 Si0.8Ge0.2 pMOSFET의 저주파잡음 특성)

  • Choi Sang-Sik;Yang Hun-Duk;Kim Sang-Hoon;Song Young-Joo;Lee Nae-Eung;Song Jong-In;Shim Kyu-Hwan
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.19 no.1
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    • pp.1-6
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    • 2006
  • High performance $Si_{0.8}Ge_{0.2}$ heterostructure metal-oxide-semiconductor field effect transistors (MOSFETs) were fabricated using well-controlled delta-doping of boron and $Si_{0.8}Ge_{0.2}$/Si heterostructure epitaxal layers grown by reduced pressure chemical vapor deposition. In this paper, we report 1/f noise characteristics of the SiGe pMOSFETs measured under various bias conditions of the gate and drain voltages changing in linear operation regions. From the noise spectral density, we found that the gate and drain voltage dependence of the noise represented same features, as usually scaled with $f^{-1}$ However, 1/f noise was found to be much lower in the device with boron delta-doped layer, by a factor of $10^{-1}_10^{-2}$ in comparison with the device fabricated without delta-doped layer. 1/f noise property of delta-doped device looks important because the device may replace bipolar transistors most commonly embedded in high-frequency oscillator circuits.