• Title/Summary/Keyword: $^7Be$

Search Result 72,895, Processing Time 0.082 seconds

A SPECTRAL LINE SURVEY FROM 159.7 TO 164.7 GHZ TOWARD ORION-KL: THE DATA

  • LEE CHANG WON;CHO SE-HYUNG
    • Journal of The Korean Astronomical Society
    • /
    • v.35 no.4
    • /
    • pp.187-196
    • /
    • 2002
  • A spectral line survey is performed from 159.7 to 164.7 GHz toward Orion-KL, as an extension of our previous line survey from 138.3 to 150.7 GHz with the same 14 m radio telescope of Taeduk Radio Astronomy Observatory. Typical system temperatures were 260 - 1000 K to achieve a sensitivity of about 0.02 - 0.04 K in TA unit. A total of 63 line spectra are detected in this survey. Among them, 54 lines lines are found to be the first detections towards an astronomical source and only 9 spectral lines have been previously identified from other observations. Forty-eight of 54 lines are believed to be from the known transitions of the known molecules, while 6 lines are 'unidentified'. All detected lines are found to be from a total of 10 molecular species and their isotopic variants. The molecular species with most numerous detected transitions are $HCOOCH_3$ (22), followed by $CH_3OCH_3$ (7), $C_2H_5CN$ (7), and $SO_2$ (6). The LTE rotation diagram analysis using all homogeneous data with those from previous survey gives more reliable determination of physical quantities. The derived values of the rotation temperatures and column densities for $HCOOCH_3$, $CH_3OCH_3$, and $SO_2$ are are 75 $\~$ 197 K and $1.5 {\~}18 {\times} 10^{15}\;cm^{-2}$, respectively.

Production of Laccase and Bioremediation of Pentachlorophenol by Wood-Degrading Fungus Trichophyton sp. LKY-7 immobilized in Ca-Alginate Beads

  • Hyunchae Jung;Kyuhwan Hyun;Park, Chongyawl
    • Journal of Korea Technical Association of The Pulp and Paper Industry
    • /
    • v.35 no.5
    • /
    • pp.80-86
    • /
    • 2003
  • The wood-degrading fungus Trichophyton sp. LKY-7 (T. LKY-7) was immobilized in ca-alginate beads for laccase production and PCP bioremediation. The immobilized T. LKY-7 enabled the repeated use of this fungus for laccase production and produced high amount of laccase throughout 5 cycles incubation. As a laccase inducer. oak wood meal (Quercus variabilis) seemed to be effective laccase inducer for T. LKY-7, and the optimum addition amount was 1% (W/W) in glucose-peptone medium. Bioremediation of pentachlorophenol by the immobilized T. LKY-7 reached an efficency of up to 90% without toxic inhibition. The immobilized T. LKY-7 might thus be applicable for semicontinuous laccase production and bioremediation to serve inoculum for reactor system.

pH Effect on the Aerobic Biodegradation of Nitrophenolic Compound in SBR (니트로페놀화합물의 호기성생물분해시 pH 영향에 관한 연구)

  • Jo, Kwan-Hyung
    • Journal of Environmental Science International
    • /
    • v.16 no.7
    • /
    • pp.779-784
    • /
    • 2007
  • Dinitrophenol is preventing cells from making energy for growth and it has been suggested that pH may be important in mitigating effects of uncouplers. The effect of pH on toxicity of dinitrophenol at high concentration was investigated, over a pH range of 5.7 to 8.7. DNP inhibition was found to be strongly dependent on mixed liquor pH. The DNP degradation rate was highest in the pH range of 7.0 to 7.8; at pH 6.0 degradation of 0.41 mM dinitrophenol was significantly inhibited; at pH <5.7, dinitrophenol degradation was completely inhibited after approximately 25% of the dinitrophenol was degraded. However no significant effect of pH variation was seen on glucose uptake by the activated sludge mixed culture.

Recombinant human BMP-2/-7 heterodimer protein expression for bone tissue engineering using recombinant baculovirus expression system

  • Park, Seung-Won;Goo, Tae-Won;Kim, Seong Ryul;Choi, Kwang-Ho
    • International Journal of Industrial Entomology and Biomaterials
    • /
    • v.32 no.2
    • /
    • pp.49-53
    • /
    • 2016
  • Bone morphogenetic proteins (BMPs) are essential growth factors for bone formation, skeletal development and bone regeneration. The BMP-2/7 heterodimer is known to have remarkable effects on osteogenic induction that are even stronger than the BMP-2 or BMP-7 homodimers. We designed a recombinant human BMP-2/7 (rhBMP-2/7) heterodimer protein with four glycine residues between BMP-2 and BMP-7 protein to facilitate free bond rotation of domains. The Baculovirus Expression Vector System (BEVS) is routinely used to produce recombinant proteins in the milligram scale. In this study, the BEVS was used to express the rhBMP-2/7 protein whrer the recombinant baculovirus was recovered in the host Sf9 cells. To confirm the biological activity of rhBMP-2/7 protein secreted from the BEVS as an osteogenic differentiation and induction factor, we measured the BMP-induced ALP activity. rhBMP-2/7 could be used as an alternative to BMPs to overcome limitations like short half-life and requirement for high concentrations. Furthermore, rhBMP-2/7 may be an efficient tool for various application studies such as bone regeneration and skeletal development.

CONTROL OF DIATOM BY PREOXIDATION AND COAGULATION IN WATER TREATMENT

  • Seo, Jeong-Mi;Kong, Dong-Soo;Ahn, Seoung-Koo;Kim, Hyun-Ook
    • Environmental Engineering Research
    • /
    • v.11 no.1
    • /
    • pp.45-53
    • /
    • 2006
  • Conventional coagulation is still the main treatment process for algae removal in water treatment. The coagulation efficiency can be significantly improved by the preoxidation of algae-containing water. Jar test was conducted to determine the optimal condition for the removal of diatoms, especially Cyclotella sp. by preoxidation and the subsequent coagulation. The effects of various concentration of PAC (Polyaluminum chloride) on coagulation with and without preoxidation using chlorine or potassium permanganate at different pHs (7.7 and 9.0) were evaluated. At pH 7.7, preoxidation with 2ppm $Cl_2$ followed by coagulation with 7.5 ppm PAC coagulant could reduce Cyclotella sp. concentration by 86%. At pH 9.0, preoxidation with 1 mg $KMnO_4/L$ followed by coagulation with 12.5 ppm PAC coagulant reduced Cyclotella sp. concentration by 85%. Non-linear regression was applied to determine the optimal condition. At pH 7.7 and 9.0, R was over 0.9, respectively. The pH of algal blooming water is over 9.0. Algae (diatom; Cyelotella sp.) can be controlled in the following ways: preoxidation with 1 mg $KMnO_4/L$ followed by coagulation with 12.5 ppm PAC coagulant can remove 80% algae from water. If water pH is adjusted to 7.7, it was expected that less amount of coagulant (7.5 or 10 mg PAC /L) after preoxidation ($Cl_2$ 2 ppm or $KMnO_4$ 0.33, 1 ppm) would be needed to achieve similar level of algae removal. The oxidation with 0.33ppm $KMnO_4$ followed by coagulation with 7.5 ppm PAC coagulant was preferable due to cost-effectiveness of treatment condition and color problem after treatment.

A Study on the Utilization and Teachers Senses of Integrated Schools by Districts (지역별(地域別) 통합운영학교(統合運營學校) 이용실태(利用實態) 및 의식조사연구(意識調査硏究))

  • Jung, Jin-ju;Kim, Seung-geun;Choi, Hyo-seung
    • Journal of the Korean Institute of Rural Architecture
    • /
    • v.3 no.3
    • /
    • pp.69-83
    • /
    • 2001
  • Based on year 2000 the 7th Educational curriculum is applied to students in elementary school 1~2 grade and it will be applied to middle school students in year 2001 and will be fully operated to the whole grade in 2003. In year 2004 it will be enforced to the whole grade in elementary middle high school. As like these changes of the educating surroundings it must emergence the uniform educations and system. It should be prepared for the age of worldwide, informational and diversity to educate in a new way. After all these changes of the educational courses will be effected to school institution and courses of elementary school and middle school to change. You can tell about the course of study in elementary school and middle school has already been in touch, by the 7th educational curriculum. The educating courses are all organized with elementary school to high school by time dividing. Like this diversified background, it is true that the study of the efficient operation of Integrated elementary school and middle school operations and a small group of schools that are just to be assimilated or also to be abolish, was not enough. So, in this course of study by looking through the policy the Integrated schools will be increasing and the 7th educational curriculum to contact by this result the educational facilities are required and for that the purpose is to design a architecture for the Integrated elementary school and middle school operation.

  • PDF

Analysis of the Content Relevance of the 7th National Science Curriculum in Secondary Schools (제7차 중등학교 과학과 교육과정 내용의 적정성 분석)

  • Lee, Yang-Rak;Park, Jae-Keun;Lee, Bong-Woo
    • Journal of The Korean Association For Science Education
    • /
    • v.26 no.7
    • /
    • pp.775-789
    • /
    • 2006
  • The purpose of this study was to analyze the relevance of the school science contents that have been implemented for the 7-10th grade students in Korea since 2001. To fulfill the purpose of the study, we 1) analyzed the 7th national science curriculum of Korea, California science standards, the national science curriculum of England, Japanese national science curriculum, and current Korean and Japanese science textbooks, 2) conducted a nationwide survey in order to gather opinions from students, teachers, and science specialists. The main findings of this research were as follows: First, the number of topics presented at each grade level should be reduced and similar topics and themes should be integrated for students' deeper understanding. Second, science contents were excessive compared to the allotted teaching time and to foreign countries. Thus, the excessive overlapping and repetition of science contents should be avoided among the primary, middle and high school level, and the number of science concepts and activities should be reduced to an appropriate level considering time allotment for science classes, teachers' workload, laboratory conditions, etc. Third, to cope with the decreasing students' understanding and interests in science as school level and school year goes up, the science curriculum and textbooks should be developed to allow for student to learn science concepts by solving problems confronted in their daily lives. Fourth, a differentiated curriculum such as in-depth and supplementary course should be described not in science contents, but in teaching and learning strategy.

MOLECULAR CORES OF THE HIGH-LATITUDE CLOUD MBM7

  • MINH Y. C.;KIM H. G.;KIM S. J.;BERGMAN P.;JOHANSSON L. E. B.
    • Journal of The Korean Astronomical Society
    • /
    • v.33 no.1
    • /
    • pp.37-45
    • /
    • 2000
  • We have investigated the properties of the high-latitude cloud MBM 7 using the 3 mm transitions of CO, CS, HCN, $HCO^+,\;C_3H_2,\;N_2H^+$, and SiO. The molecular component of MBM 7 shows a very clumpy structure with a size of $\le$0.5 pc, elongated along the northwest-southeast direction, perpendicularly to an extended HI component, which could be resulted from shock formation. We have derived physical properties for two molecular cores in the central region. Their sizes are 0.1-0.3 pc and masses 1-2 M$\bigodot$ having an average volume density $\~2{\times}10^3 cm^{-3}$ at the peak of molecular emission. We have tested the stability of the cores using the full version of the virial theorem and found that the cores are stabilized with ambient medium, and they are expected not to be dissipated easily without external perturbations. Therefore MBM 7 does not seem to be a site for new star formation. The molecular abundances in the densest core appear to be much less (by about one order of magnitude) than the 'general' dark cloud values. If the depletions of heavy elements are not significant in the HLCs compared with those in typical dark clouds, our results may suggest different chemical evolutionary stages or different chemical environments of the HLCs compared with dense dark clouds in the Galactic plane.

  • PDF

The vacancy diffusion and the formation of dislocation in graphene : Tight-binding molecular dynamics simulation

  • Lee, Gun-Do;Yoon, Eui-Joon;Hwang, Nong-Moon
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2010.08a
    • /
    • pp.54-55
    • /
    • 2010
  • Vacancy defects in graphene can be created by electron or ion irradiation and those induce ripples which can change the electronic properties of graphene. Recently, the formation of defect structures such as vacancy defects and non-hexagonal rings has been reported in the high resolution transmission electron microscope (HR-TEM) of reduced graphene oxide [1]. In those HR-TEM images, it is noticed that the dislocations with pentagon-heptagon (5-7) pairs are formed and diffuses. Interestingly, it is also observed that two 5-7 pairs are separated and diffuse far away from each other. The separation of 5-7 pairs has been known to be due to their self-diffusion. However, from our tight-binding molecular dynamics simulation, it is found that the separation of 5-7 pairs is due to the diffusion of single vacancy defects and coalescence with 5-7 pairs. The diffusion and coalescence of single vacancy defects is too fast to be observed even in HR-TEM. We also implemented Van der Waals interaction in our tight-binding carbon model to describe correctly bi-layer and multi-layer graphene. The compressibility of graphite along c-axis in our tight-binding calculation is found to be in excellent agreement with experiment. We also discuss the difference between single layer and bi-layer graphene about vacancy diffusion and reconstruction.

  • PDF

Preventive Effect of Lysis in the Cadmium-Tolerant Hansenula anomala B-7 Cells by Metal Ions (금속 이온에 의한 카드늄 내성균주 Hansenula anomala B-7 세포의 용균 방지 효과)

  • Song, Hyung-Ik;Yu, Tae-Shick
    • The Korean Journal of Mycology
    • /
    • v.19 no.4
    • /
    • pp.282-284
    • /
    • 1991
  • The yeast, Hansenula anomala B-7, isolated from the $Cd^{2+}$ rich soils and determined to be tolerant in the high concentration of $Cd^{2+}$ were employed in this work. Its intact cells grown in high concentration of $Cd^{2+}$ were observed to be Iysed at the early stage when transferred to a cadmium deficient broth. Its intact cells found to be not Iysed and grow well under the high concentration of $Cd^{2+}$. The Iysis of the intact cells grown at the high concentration of $Cd^{2+}$ ion was not found when the metal ions were replaced with $Cd^{2+}$ ion in the same concentration. This result indicated that Iysis of yeast cells, at least in this isolate, would be related to cell osmosis with the mineral ions added.

  • PDF