• Title/Summary/Keyword: Research Synthesis

Search Result 5,464, Processing Time 0.038 seconds

Solution-Phase Synthesis of Shape-Controlled Metal Nanocrystals

  • Im, Byeong-Gwon
    • Proceedings of the Materials Research Society of Korea Conference
    • /
    • 2011.05a
    • /
    • pp.21.1-21.1
    • /
    • 2011
  • Controlling the morphology of a metal nanocrystal is critical to modern materials chemistry because its physical and chemical properties can be easily and widely tuned by tailoring the size and shape. Combined with ease of synthesis and processing, metal nanocrystals with desired morphologies and thus properties are promising candidates for a wide variety of applications in catalysis, sensing, imaging, electronics, and photonics, and medicine. In this talk, I would like to introduce my recent research results on the shape-controlled synthesis of metal nanocrystals using a simple aqueous method. This water-based system provides a number of merits such as simplicity, convenience, and the potential for large-scale production and enables us to synthesize metal nanocrystals with a rich variety of shapes such as truncated octahedron, cubes, bars, octahedrons, and thin plates. The ability to control the shape of metal nanocrystals provides a great opportunity to systematically investigate their catalytic and optical properties.

  • PDF

Effects of Ginseng Saponin on DNA Strand Breaks and Replication Inhibition by Benzo(a)Pyrene in CHO-Kl Cells (Benzo(a)Pyrene 유발 DNA 상해 및 복제 억제에 미치는 인삼사포닌의 영향)

  • Park, Jin-Kyu;Park, Ki-Hyun
    • Journal of Ginseng Research
    • /
    • v.16 no.3
    • /
    • pp.210-216
    • /
    • 1992
  • The effect of saponin extracted from Panax grneng CA Meyer on DNA repair and replicative DNA synthesis were examined in CHO-Kl cells cotreated with benzo(a)pyrene and rat liver S-15 fraction. The DNA strand breaks inititated by benzo(a)pyrene metabolites were measured by alkaline election technique. The addition of ginseng saponin to the culture media resulted in decrease of benzo(a)pyrene-induced DNA strand breaks, and restored the suppressed-semiconservative-DNA-synthesis by the carcinogen. DNA repair synthesis in the damaged cells was also elevated by the ginseng treatment when the repairing activites were measured for the (3H)-thymidine incorporation into the carcinogen damaged cellular DNk Comparative analysis of DNA-adduces of benzo(a)pyrene metabortes in microsomes suggested that ginseng saponin treatment in rats reduced the formation of electrophilic metabolites of benzo (a)-pyrene in the rat liver microsomes.

  • PDF

Simultaneous Synthesis and Densification of Ti5Si3 and Ti5Si3-20 vol%Nb Composite by Field-Activated and Pressure-Assisted Combustion

  • Shon, In Jin;Kim, Hwan Chal;Rho, Dae Ho
    • The Korean Journal of Ceramics
    • /
    • v.5 no.2
    • /
    • pp.148-154
    • /
    • 1999
  • A method to simultaneously synthesize and consolidate $Ti_5Si_4 \;and\; Ti_5Si_3$-20 vol%Nb composite from powders of Ti, Si and Nb was investigated. Combustion synthesis was carried out under the combined effect of an electric field and mechanical pressure. Highly dense $Ti_5Si_4 \;and\; Ti_5Si_3$-20 vol% Nb with relative densities up to 98% was produced from powders of Ti, Si and Nb under the application of 60 MPa pressure and 3000A current on the reactant.

  • PDF

Exploring Theory Synthesis through an Analysis of Situation-specific Theories in Korea (상황특이적 이론 합성을 통한 한국적 간호이론 개념 개발)

  • Suh, Eun-Young
    • Perspectives in Nursing Science
    • /
    • v.8 no.1
    • /
    • pp.10-19
    • /
    • 2011
  • Purpose: This article was proposed to describe and summarize the following 1) the structural hierarchy of nursing knowledge and 2) the four different methods of concept analysis and concept development, which are used most frequently in nursing literature, and 3) to demonstrate a qualitative data synthesis of situation-specific theories in Korea in order to provide an venue for developing Korean-contextualized nursing theory. Methods: A literature review and a meta-synthesis were used. An interpretive integration method for the meta-synthesis was used to incorporate incorporating the results of ten qualitative studies in Korea. Results: The normative and extended concept of the self was one of the three foremost concepts. The experiences of being detached from a group and of being unlike others were perceived with distress to Korean participants. Lastly, as a coping method, complying with a higher flow or power was used. Conclusion: Based on the three concepts elicited in this article, a substantive theory which withholds Korean nursing concepts and essences is hoped to be developed in future.

  • PDF

Reference Functions for Synthesis and Analysis of Multiview and Integral Images

  • Saveljev, Vladimir;Kim, Sung-Kyu
    • Journal of the Optical Society of Korea
    • /
    • v.17 no.2
    • /
    • pp.148-161
    • /
    • 2013
  • We propose one- and two-dimensional reference functions for processing of integral/multiview imaging. The functions provide the synthesis/analysis of the integral image by distance, as an alternative to the composition/decomposition by view images (directions). The synthesized image was observed experimentally. In analysis confirmed by simulation in a qualitative sense, the distance was obtained by convolution of the integral image with the reference functions.

Synthesis of Sulfide-based Phosphors by Multiply Combined Methods Based Upon Inorganic Chemistry

  • Kakihana, Masato;Petrykin, Valery
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2009.10a
    • /
    • pp.121-124
    • /
    • 2009
  • We developed a panel of innovative solution-based approaches for synthesis of multicomponent sulfide phosphor materials. The application of these synthesis strategies allowed for preparation of high-purity and high-brightness $BaAl_2S_4:Eu$ and $Ba_2SiS_4:Eu$ phosphors and led to the discovery of new phosphors suitable for application in the LED-based lighting including $Sr_2ZnS_3:Eu$, $CaBaSiS_4:Eu$ and $(Ba,Sr)_2ZnS_3:Eu$.

  • PDF

Small-Angle X-ray Scattering Station 4C2 BL of Pohang Accelerator Laboratory for Advance in Korean Polymer Science

  • Yoon, Jin-Hwan;Kim, Kwang-Woo;Kim, Je-Han;Heo, Kyu-Young;Jin, Kyeong-Sik;Jin, Sang-Woo;Shin, Tae-Joo;Lee, Byeong-Du;Rho, Ye-Cheol;Ahn, Byung-Cheol;Ree, Moon-Hor
    • Macromolecular Research
    • /
    • v.16 no.7
    • /
    • pp.575-585
    • /
    • 2008
  • There are two beamlines (BLs), 4C1 and 4C2, at the Pohang Accelerator Laboratory that are dedicated to small angle X-ray scattering (SAXS). The 4C1 BL was constructed in early 2000 and is open to public users, including both domestic and foreign researchers. In 2003, construction of the second SAXS BL, 4C2, was complete and commissioning and user support were started. The 4C2 BL uses the same bending magnet as its light source as the 4C1 BL. The 4C1 BL uses a synthetic double multilayer monochromator, whereas the 4C2 BL uses a Si(111) double crystal monochromator for both small angle and wide angle X-ray scattering. In the 4C2 BL, the collimating mirror is positioned behind the monochromator in order to enhance the beam flux and energy resolution. A toroidal focusing mirror is positioned in front of the monochromator to increase the beam flux and eliminate higher harmonics. The 4C2 BL also contains a digital cooled charge coupled detector, which has a wide dynamic range and good sensitivity to weak scattering, thereby making it suitable for a range of SAXS and wide angle X-ray scattering experiments. The general performance of the 4C2 BL was initially tested using standard samples and further confirmed by the experience of users during three years of operation. In addition, several grazing incidence X-ray scattering measurements were carried out at the 4C2 BL.

The Impact of Cancer Diagnosis and Its Treatment on Korean Women's Lives: A Meta-synthesis Study

  • Suh, Eunyoung E.
    • Korean Journal of Adult Nursing
    • /
    • v.27 no.1
    • /
    • pp.117-126
    • /
    • 2015
  • Purpose: Korean women, who have come to the forefront at a risk of cancer, have been notable objects for qualitative nursing research in last a couple of decades. Given the imparity and varieties of those findings, this study was aimed to synthesize the impact of cancer diagnosis and its treatment on Korean women's lives using a qualitative meta-synthesis method. Methods: By searching five English-based databases and four Korean databases, 21 qualitative studies on Korean women's particular experiences of cancer diagnosis and treatment since 2000 were included. Using a meta-synthesis process by Sandelowski & Barroso (2007), the selected studies were synthesized for interpretive integration of the findings. Results: The meta-synthesis elicited three themes: detachment from the usualness, awareness of profound desires, and redefinition of every relation. With destructive experiences of a diagnosis and its treatments, Korean women felt apart from their everyday life, daily roles, and even from their own body. They then grasped a strong desire for life and for beauty, and reconfirmed the sense of mission for being a mother. Those changes made them to reconstruct all relations surrounded them. Conclusion: The findings yield a substantive portrait of the given issue, which could be helpful for health care professionals.