• Title/Summary/Keyword: synthetic temperature

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ORFEUS OBSERVATIONS OF ULTRAVIOLET EXCITED HIGH-J MOLECULAR HYDROGEN

  • Lee, Dae-Hee;Dixon, W. Van Dyke;Min, Kyoung-Wook;Pak, Soo-Jong
    • Journal of The Korean Astronomical Society
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    • v.42 no.6
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    • pp.145-153
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    • 2009
  • We present measurements of diffuse interstellar $H_2$ absorption lines in the continuum spectra of 10 early-type stars. The data were observed with the Berkeley Extreme and Far-Ultraviolet Spectrometer (BEFS) of the ORFEUS telescope on board the ORFEUS-SPAS I and II space-shuttle missions in 1993 and 1996, respectively. The spectra extend from the interstellar cutoff at 912 $\AA$ to about 1200 $\AA$ with a resolution of ~ 3000 and statistical signal-to-noise ratios between 10 and 65. Adopting Doppler broadening velocities from high-resolution optical observations, we obtain the $H_2$ column densities of rotational levels J" = 0 through 5 for each line of sight. The kinetic temperatures derived from J" = 0 and 1 states show a small variation around the mean value of 80 K, except for the component toward HD 219188, which has a temperature of 211 K. Based on a synthetic interstellar cloud model described in our previous work, we derive the incident UV intensity IUV and the hydrogen density $n_H$ of the observed components to be -0.4 $\leq$ log $I_{UV}\leq2.2$ and $6.3{\leq}n_H2500cm^{-3}$, respectively.

Replacement of the antifreeze-like domain of human N-acetylneuraminic acid phosphate synthase with the mouse antifreeze-like domain impacts both N-acetylneuraminic acid 9-phosphate synthase and 2-keto-3-deoxy-D-glycero-Dgalacto- nonulosonic acid 9-phosphate synthase activities

  • Reaves, Marshall Louis;Lopez, Linda Carolyn;Daskalova, Sasha Milcheva
    • BMB Reports
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    • v.41 no.1
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    • pp.72-78
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    • 2008
  • Human NeuNAc-9-P synthase is a two-domain protein with ability to synthesize both NeuNAc-9-P and KDN-9-P. Its mouse counterpart differs by only 20 out of 359 amino acids but does not produce KDN-9-P. By replacing the AFL domain of the human NeuNAc-9-P synthase which accommodates 12 of these differences, with the mouse AFL domain we examined its importance for the secondary KDN-9-P synthetic activity. The chimeric protein retained almost half of the ability of the human enzyme for KDN-9-P synthesis while the NeuNAc-9-P production was reduced to less than 10%. Data from the homology modeling and the effect of divalent ions and temperature on the enzyme activities suggest conformational differences between the human and mouse AFL domains that alter the shape of the cavity accommodating the substrates. Therefore, although the AFL domain itself does not define the ability of the human enzyme for KDN-9-P synthesis, it is important for both activities by aiding optimal positioning of the substrates.

Dyeing Properties of Microbial Violacein on Mutifiber Fabrics (미생물 violacein 색소의 다섬교직포에서의 염색성)

  • Choi, Jong-Myoung;Kim, Yong-Sook
    • Fashion & Textile Research Journal
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    • v.11 no.5
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    • pp.818-826
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    • 2009
  • Dyeability of microbial violacein produced from Chromobacterum violaceum CV107 on to multifiber fabrics has been studied. The bluish-purple colourants were produced by cultivation of Chromobacterum violaceum using LB liquid medium for 2 days. The colourant was extracted with 80% acetone and identified as violacein by LC/MS analysis. The violacein could be dyed on not only natural fibers such as Cotton, Silk and Wool but also synthetic fibers such as Diacetate, Triacetate, Creslan 61 and Nylon 66. Maximum K/S values were shown at 540-580 nm according to different fiber with color appearance of purple or blue. An optimum pH and temperature under dyeing condition were 10 and $70^{\circ}C$, respectively. Any mordants were not improved colour density and quality on various fabrics. From this studies, pigments produced microbe have a high potentials for natural dyeing on fabrics. Finally, development of new colourants from microbe has made a possible change for new dyeing field in respects of eco-friend and repeatability of natural dyeing for apparels.

Synthesis of Cobalt Phosphates and their Catalytic Properties of the Hydrogen Generation from the Hydrolysis of NaBH4 (비결정질 코발트 인산염 합성 및 NaBH4 가수분해를 통한 수소발생 촉매 활성 연구)

  • Kim, Youngyong;Park, Joon Bum;Kwon, Ki-Young
    • Applied Chemistry for Engineering
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    • v.26 no.6
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    • pp.743-745
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    • 2015
  • Amorphous cobalt phosphates were synthesized with their distinct morphology by controlling the amount of base in the synthetic condition. The crystallinity and morphology of cobalt phosphates were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The prepared cobalt phosphates were applied as a heterogeneous catalyst for generating hydrogen gas from the hydrolysis reaction of sodium borohydride. We found that the catalyst prepared using the least amount of base condition at room temperature showed a plate shape with less than 10 nm thickness, which resulted in the best catalytic activity among all catalysts due to the large surface area.

Natural dyeing of cow leather with cochineal (코치닐을 활용한 우피의 천연염색)

  • Kim, Sangyool
    • The Research Journal of the Costume Culture
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    • v.24 no.6
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    • pp.817-824
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    • 2016
  • The introduction of natural dyes into modern dye houses is very promising green chemistry concept that should be popularized more to reduce the dependency of leather dyeing on some toxic and non-biodegradable synthetic dyes. In this study, the properties of dyeing of cochineal on cow leather were evaluated. The proper dyeing conditions were identified with dye uptake (K/S values) depending on the colorant concentration, dyeing duration, dyeing temperature, and dye bath pH. For the proper mordanting conditions, color changes for different mordants were observed as $La^{*}b^{*}$ and H V/C values. Color fastness (light, rubbing, and dry cleaning) was also examined. Additionally, antibacterial properties and UV protection were examined. The results were as follows: The optimized dyeing conditions were 300% o.w.f., $40^{\circ}C$, 40 min., and pH 5. The cow leather color was red in the absence of mordanting, while it was red purple after being mordanted with Al and Cu, and purple mordanted with Fe. The K/S value of cow leathers increased in the order of the dyeing using $AlK(SO_4)_2$ > $CuSO_4$ > $FeSO_4$. The colorfastness to light and rubbing were reduced compared to original (untreated) cow leather. However dry cleaning fastness was very satisfactory, with a 4~5 rating. The dyed and pre-mordanting dyed cow leather showed excellent antibacterial properties.

A Study on Mechanical Properties Changes to Improve the Confidence of Remaining Life Evaluation for the Weldment of Power Plant Boiler Tube(SA213-T12) (발전설비 보일러 튜브 용접부의 잔여수명평가 신뢰성 향상을 위한 기계적 물성 변화 연구(SA213-T12))

  • Oh, Byungjin;Jang, Joong Soon
    • Journal of Welding and Joining
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    • v.32 no.3
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    • pp.102-107
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    • 2014
  • Boiler equipment in power plant is always being operated in harsh conditions and severely exposed to the extreme environment of high temperature. Therefore periodically the state of devices should be checked, diagnosed, and analyzed to ensure the reliability of the equipment. Traditionally, such a diagnosis is based one or two physical properties of the sample taken from the equipment like hardness, microstructure, etc.. However, to enhance the confidence of the diagnosis, it is necessary to synthesize those properties together. This paper is to propose such a synthetic procedure for SA213-T12(1Cr-0.5Mo) which was developed to be used in $565^{\circ}C$ below condition. Creep test and accelerated degradation test were performed simultaneously, and the physical properties such as microstructure, tensile strength, yield strength, hardness, and indentation properties were measured. This paper proposes a method of determining the remaining life by quantitative comparison. It will provide the basis of evaluating life assessment more objective and reliable.

Performance Evaluation of a $SF_6$ Gas Circuit Breaker with Experimental Investigation (초고압 $SF_6$ 가스 차단기의 실험적 차단성능 평가)

  • Jeong, Y.W.;Park, H.T.;Oh, I.S.
    • Proceedings of the KIEE Conference
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    • 2005.11a
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    • pp.96-99
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    • 2005
  • In this study, we build system and techniques of evaluating the interruption performance of the GCB with experimental method. We constructed a simplified synthetic test circuit of which ability is up to 245kV, 50kA BTF test. And We composed a model test circuit breaker with puffer assisted self blasting type GCB. With this circuit breaker, we carried out the experiment of no load and SLF90. During the tests, we measured the several factors such as stroke, pressure, arc temperature, the voltage and current near the current zero and dI/dt, dV/dt. Arc conductivity before 200ns before current zero which is one of the indexes of the thermal recovery of a GCB was measured. With these kinds of measurement, we could estimate the performance of a GCB fundamentally. Futhermore these results were used to adjust the arc modeling with CFD(computational fluid dynamics) and we could increase the plausibility of the analytical method.

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Fabrication of Microstructures with Nanocomposites by Capillary Effect (모세관법을 이용한 나노 복합재료 마이크로 구조 제작)

  • Han, Soo-Ho;Hwang, Hui-Yun
    • Composites Research
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    • v.31 no.4
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    • pp.171-176
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    • 2018
  • We proposed new and easy fabrication method of micro-nano hierarchical structures for synthetic dry adhesives and conducted feasibility tests of alignment characteristics of nano-materials in the microstructures by capillary effect. Candidates of fabrication conditions were selected based on the degree of cure and viscosity of mixtures of multiwall carbon nanotubes (MWCNTs) and polydimethylsiloxane (PDMS), which were measured with respect to the fabrication conditions. Scanning electron microscopy images of cross sections of MWCNT-PDMS microstructures were analyzed. MWCNT alignment in microstructures was better when fabrication temperature and degree of cure at fabricating start were lower, but areal density of MWCNTs was little affected by fabrication conditions.

Antiproliferative Effects of Crocin in HepG2 Cells by Telomerase Inhibition and hTERT Down-Regulation

  • Noureini, Sakineh Kazemi;Wink, Michael
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.5
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    • pp.2305-2309
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    • 2012
  • Crocin, the main pigment of Crocus sativus L., has been shown to have antiproliferative effects on cancer cells, but the involved mechanisms are only poor understood. This study focused on probable effect of crocin on the immortality of hepatic cancer cells. Cytotoxicity of crocin ($IC_{50}$ 3 mg/ml) in hepatocarcinoma HepG2 cells was determined after 48 h by neutral red uptake assay and MTT test. Immortality was investigated through quantification of relative telomerase activity with a quantitative real-time PCR-based telomerase repeat amplification protocol (qTRAP). Telomerase activity in 0.5 ${\mu}g$ protein extract of HepG2 cells treated with 3 mg/ml crocin was reduced to about 51% as compared to untreated control cells. Two mechanisms of inhibition, i.e. interaction of crocin with telomeric quadruplex sequences and down regulation of hTERT expression, were examined using FRET analysis to measure melting temperature of a synthetic telomeric oligonucleotide in the presence of crocin and quantitative real-time RT-PCR, respectively. No significant changes were observed in the $T_m$ telomeric oligonucleotides, while the relative expression level of the catalytic subunit of telomerase (hTERT) gene showed a 60% decrease as compared to untreated control cells. In conclusion, telomerase activity of HepG2 cells decreases after treatment with crocin, which is probably caused by down-regulation of the expression of the catalytic subunit of the enzyme.

Combinatorial Synthesis and Screening of the Tb-activated Phosphors in the System CaO-Y2O3-Al2O3 (조합화학을 이용한 CaO-Y2O3-Al2O3계의 Tb활성 형광체의 합성 및 검색)

  • Yoon, Ho-Shin;Kim, Chang-Hae;Kang, Yun-Chan;Ryu, Seung-Kon;Park, Hee-Dong
    • Korean Journal of Materials Research
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    • v.13 no.12
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    • pp.785-790
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    • 2003
  • We have synthesized some phosphors in the system $CaO-Y_2$$O_3$-$Al_2$$O_3$by combinatorial polymerized-complex method. Composition and synthetic temperature of phosphors in the library was screened from the emission intensities of individual samples under VUV excitation. In $Tb^{ 3+}$-activated $CaO-Y_2$$O_3$-$Al_2$$O_3$, green phosphors showing good intensity were found to be X$O_3$$O_{7}$, CaYA1O$_4$, YA1O$_3$, $Y_3$$Al_{5}$$O_{12}$, $Y_4$$A1_2$$O_{9}$ .