• Title/Summary/Keyword: chemical communication

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Pharmacognostical Evaluation of the Roots of Pseudarthria viscida (Linn.)

  • Rajendran, K.;Srinivasan, K.K.;Shirwaikar, Annie
    • Natural Product Sciences
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    • v.13 no.3
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    • pp.214-219
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    • 2007
  • The roots of Pseudarthria viscida (L.) Wight and Arnott. (Leguminosae) are used against various disorders in Indian systems of medicine, namely as anthelmintic, anti-inflammatory, cardiotonic, aphrodisiac, rejuvenating, tonic and as a remedy for cough, asthma, tuberculosis, diarrhoea and alternate fever. The present communication deals with the detailed pharmacognostical evaluation of the root sample using light and confocal microscopy, WHO recommended physico-chemical determinations and authentic phytochemical procedures. he physico-chemical, morphological and histological parameters presented in this paper may be proposed as parameters to establish the authenticity of P. viscida root and may possibly help to differentiate the drug from its other species.

Theoretical Approach for the Structures, Energetics and Spectroscopic Properties of (H2O3)n (n = 1-5) Clusters

  • Seo, Hyun-Il;Bahng, Jin-Ah;Kim, Yeon-Cheol;Kim, Seung-Joon
    • Bulletin of the Korean Chemical Society
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    • v.33 no.9
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    • pp.3017-3024
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    • 2012
  • The geometrical parameters, vibrational frequencies, and binding energies for $(H_2O_3)_n$ (n = 1-5) have been investigated using various quantum mechanical techniques. The possible structures of the clusters (n = 2-5) are fully optimized and the binding energies are predicted using energy differences at each optimized geometry. The harmonic vibrational frequencies are also determined and zero-point vibrational energies (ZPVEs) are considered for the better prediction of the binding energy. The best estimation of the binding energy for the dimer is 8.65 kcal/mol. For n = 2 and 3, linear structures with all trans forms of the HOOOH monomers are predicted to be the lowest conformations in energy, while the cyclic structures with all cis-HOOOH monomers are preferable structures for n = 4 and 5.

Recent Development of Linear Scaling Quantum Theories in GAMESS

  • Choi, Cheol-Ho
    • Bulletin of the Korean Chemical Society
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    • v.24 no.6
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    • pp.733-738
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    • 2003
  • Linear scaling quantum theories are reviewed especially focusing on the method adopted in GAMESS. The three key translation equations of the fast multipole method (FMM) are deduced from the general polypolar expansions given earlier by Steinborn and Ruedenberg. Simplifications are introduced for the rotation-based FMM that lead to a very compact FMM formalism. The OPS (optimum parameter searching) procedure, a stable and efficient way of obtaining the optimum set of FMM parameters, is established with complete control over the tolerable error ε. In addition, a new parallel FMM algorithm, requiring virtually no inter-node communication, is suggested which is suitable for the parallel construction of Fock matrices in electronic structure calculations.

Prediction of Lytic Segments from Bacillus thuringiensis var israelensis 130 kDa and 72 kDa Proteins

  • Suvarchala Devi, V.;Jamil, Kaiser
    • BMB Reports
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    • v.34 no.2
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    • pp.130-133
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    • 2001
  • The amino acid sequences of 130 kDa and 72 kDa proteins responsible for the larvicidal activity of Bacillus thuringiensis var israelensis (Bti) were analyzed by hydrophobic moment plots. A search for highly amphiphilic $\alpha$-helices was made in these proteins using the helical hydrophobic moment as a criterion of amphiphilicity The protein segments of the largest hydrophobic moments were analyzed. In the present communication we report the surface seeking helices in 130 kDa and 72 kDa proteins of Bacillus thuringiensis var israelensis. It is assumed that the surface seeking segments may participate in one of the membrane-related functions of Bacillus thuringiensis.

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A Study on the Characteristics of Conductive Paste for Roll-to-Roll Printing (Roll to Roll Printing용 전도성 Paste 물성 연구)

  • Cho, Mi-Jeong;Nam, Su-Yong
    • Proceedings of the Korean Printing Society Conference
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    • 2007.11a
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    • pp.59-64
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    • 2007
  • We have manufactured low-curable silver pastes for gravure printing out of roll to roll printing process. When printing, the pastes be used different silver powder shape because of the printing characteristics. The pastes were prepared with silver powder by silver powder shape, polyester resin, solvent and homogenized on a standard three-roller mill. And the pastes exhibited a shear-thinning flow at viscosity profile. Moreover the adhesive strength and resistivity of silver film had good characteristics. With the manufactured paste in this study, RFID antenna circuit had flexible is manufactured and it had $10^{-4}{\sim}10^{-5}{\Omega}{\cdot}cm$.

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A Study on the Characteristics of Low Temperature Firing Phosphor Paste for Flat Light Source (면광원용 저온 소성형 형광체 Paste 특성 연구)

  • Lee, Dong-Wook;Nam, Su-Yong
    • Proceedings of the Korean Printing Society Conference
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    • 2007.11a
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    • pp.75-81
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    • 2007
  • As manufacturing the low temperature firing paste applicable flat light source for LCD BLU, this study examined the specific quality. For the phosphor pastes, the low temperature firing acryl resin is used as the binder resin. As the result of thermal decomposition characteristics, residual hydroxylcarbon rested under 0.1wt% on 400$^{\circ}C$. With the manufactured paste in this study, the flat light source device is manufactured through the screen printing and it brought the almost 100% of special quality radiation about the phosphor brightness.

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Study on the Formation of SiOC Films and the Appropriate Annealing Temperature

  • Oh, Teresa
    • Journal of information and communication convergence engineering
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    • v.9 no.2
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    • pp.217-219
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    • 2011
  • As silicon devices shrink and their density increases, the low dielectric constant materials instead of $SiO_2$ film is required. SiOC film as low-k films was deposited by the capacitively coupled plasma chemical vapor deposition and then annealed at $300{\sim}500^{\circ}C$ to find out the properties of the dependence on the temperature and polarity. This study researched the dielectric constant using by the structure of the metal/SiOC film/p-Si, chemical shift, thickness, refractive index and hardness. The trend of reflective index was inverse proportioned the thickness, but the dielectric constant was proportioned it. The dielectric constant decreased with decreasing the thickness and the increment of the refractive index.

Chemical Synthesis of a Human Lysozyme Gene and Expression in Saccharomyces cerervisiae (Human Lysozyme 유전자의 화학적 합성과 Saccharomyces cerevisiae 에서의 발현)

  • 김기운;이승철;황용일
    • Microbiology and Biotechnology Letters
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    • v.23 no.2
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    • pp.138-144
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    • 1995
  • The cDNA, encoding human lysozyme (HLY) which was isolated from a human placenta cDNA library, has been well characterized (Yoshimura et al., 1988). Based on the communication, we have prepared an artificial HLY gene from chemically synthesized 38-oligomer with high codon usage in Saccharomyces cerevisiae. For directing the synthesis and secretion of HLY in S. cerevisiae, an expression vector, pHKl was constructed by inserting the HLY gene, containing a synthetic HLY secretion signal sequence, between the yeast GAP promoter and PH05 terminator. From a lysoplate assay, we have confirmed an yeast transformant harboring a pHK1 which makes a clearing zone on the overlayed Micrococcus luteus. This result means a chemically synthesized HLY gene which was normally expressed and secreted in yeast.

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The Properties of Polymer Concrete Recycling Plastic Waste (폐플라스틱을 재활용한 폴리머 콘크리트 특성)

  • 조병완;문린곤;박승국;임상헌
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.11a
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    • pp.441-444
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    • 2003
  • Polymer concrete has more useful than cement concrete in the strength and durability. So, it is widely utilizing as panel for wall, manhole for communication, foundation and underground connection box, etc. But polymer concrete is a defect that is disadvantageous in economical aspect because cost of resin is expensive. Polymer concrete (PC) using unsaturated polyester resins based on recycled polyethylene terephthalate(PET) plastic waste were used in our study for grasping its mechanical properties such as compressive strength, tensile strength, flexural strength and chemical resistance was tested by dealing with 20% HCl, 30% NaOH. As a result of it, compressive, tensile and flexural strength of PC indicated 752kgf/$\textrm{cm}^2$, 80kgf/$\textrm{cm}^2$ and 243kgf/$\textrm{cm}^2$ kind of satisfaction successively. Also, properties of chemical resistance are superior to those of cement concrete.

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Molecular Dynamics Simulations Study on Abrasive's Speed Change Under Pad Compression (연마패드 압력에 따른 연마입자 이동속도 변화의 분자동역학적 시뮬레이션 연구)

  • Lee, Gyoo-Yeong;Lee, Jun-Ha;Kim, Tae-Eun
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.25 no.7
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    • pp.569-573
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    • 2012
  • We investigated the speed change of the diamond spherical abrasive during the substrate surface polishing under the pad compression by using classical molecular dynamics modeling. We performed three-dimensional molecular dynamics simulations using the Morse potential functions for the copper substrate and the Tersoff potential function for the diamond abrasive. As the compressive pressure increased, the indented depth of the diamond abrasive increased and then, the speed of the diamond abrasive along the direction of the pad moving was decreased. Molecular simulation result such as the abrasive speed decreasing due to the pad pressure increasing gave important information for the chemical mechanical polishing including the mechanical removal rate with both the pad speed and the pad compressive pressure.