• Title/Summary/Keyword: wave nature

Search Result 207, Processing Time 0.026 seconds

The Inhibition of Epileptogenesis During Status Epilepticus by Ginsenosides of Korean Red Ginseng and Ginseng Cell Culture (Dan25)

  • N.E., Chepurnova;Park, Jin-Kyu;O.M., Redkozubova;A.A., Pravdukhina;K.R., Abbasova;E.V., Buzinova;A.A., Mirina;D.A., Chepurnova;A.A., Dubina;U.A., Pirogov;M., De Curtis;L., Uva;S.A., Chepurnov
    • Journal of Ginseng Research
    • /
    • v.31 no.3
    • /
    • pp.159-174
    • /
    • 2007
  • Pharmacology of Korean Red ginseng gives us unique possibility to develop new class of antiepileptic drugs today and to improve one's biological activity. The chemical structures of ginsenosides (GS) have some principal differences from well-known antiepileptic new generation drugs. The antiepileptic effect of GS was also demonstrated in all models of epilepsy in rats (young and adult), which have studied, in all models of epilepsy including status epilepticus (SE), induced by lithium - pilocarpine. In our experiments in rats new evidences on protective effects were exerted as a result of premedication by GS. Pre-treatment of several GS could induce decrease of the seizures severity and brain structural damage (by MRI), neuronal degeneration in hippocampus. Wave nature of severity of motor seizures during convulsive SE was observed during lithium-pilocarpine model of SE in rats (the first increase of seizures was 30 min after the beginning of SE and the second - 90 min after. The efficacy of treatment on SE by ginsenoside as expected was observed after no less 3 weeks by daily GS i.p. administration. It is blocked SE or significantly decrease the severity of seizures during SE. The implication of presented data is that combination of ginsenosides from Korean Red ginseng and ginseng cell culture Dan25 that could be applied for prevention of epileptical status development. However, a development of optimal ratio of different ginsenosides $(Rb_1$ Rc, Rg, Rf,) should consummate in the new antiepileptic drug development.

The Artistic Expression of European Paintings of the $19^{th}$ Century and Kosode Design in Edo Era, Focusing on the Influence of Ukiyo-e (우끼요에를 중심으로 본 19세기 유럽회화와 에도시대 고소데 디자인의 예술적 표현)

  • Lee, Keum-Hee;Lee, So-Ryoung;Byun, Jee-Yeon
    • Journal of the Korean Society of Costume
    • /
    • v.60 no.4
    • /
    • pp.76-97
    • /
    • 2010
  • The purpose of this study is to review the influence of Ukiyo-e on the design of European Paintings of the $19^{th}$ century and the expression of the design of Kosode design in Edo-era. We collected data from the actual study of visiting Museums and other theories and visual materials through literature review. Then, we analyzed the data. The result came out that Ukiyo-e, which is the genre painting of Edo-era, provided the new vision and the new way of expression to the European Paintings of the $19^{th}$ century. In the same way, the result also indicated that Ukiyo-e similarly influenced on the design of Kosode. For example, the study showed that the patterns of Kosode, such as flower, bridge, fun, wave, Lotus flower, stripe, oval, plaid, were used in the works of European artists in the $19^{th}$ century. The Ukiyo-e styles include Kan Bun style, Dan-Gawari style, Back facing style, Two-Section Segmentation style, and Folding screen style, with the identity of Japan and Japanese unique nature and landscapes. Thus, this study proved the design of Kosode to be the frontier of both European and Japanese arts, by examining Ukioyo-e's plastic characteristics, its composition & arrangements, and its subjects & objects which were samely revealed in Kosode design and European Art in nineteenth century.

A First-principles Study on the Electronic Structures and Magnetism of Antiperovskite Ti0.96Co0.02Fe0.02O2 (페로브스카이트 구조를 가지는 Ti0.96Co0.02Fe0.02O2의 전자구조와 자성)

  • Song, Ki-Myung;Bialek, B.;Lee, Jae-Il
    • Journal of the Korean Magnetics Society
    • /
    • v.18 no.3
    • /
    • pp.85-88
    • /
    • 2008
  • We calculated the electronic structures of substituted cobalt nitrides, that is $FeCo_3N$ and $NiCo_3Ni$, by using the all electron fullpotential linearized augmented plane-wave (FLAPW) energy band method, and investigated the influence on the magnetic properties of $Co_4N$ due to the substitution of Co atom located at corner sites by iron and nickel atoms. We found that the magnetic moments of CoII atoms located at the face-center positions in these compounds are almost same to that of $Co_4N$. The magnetic moments of Fe and Ni atoms in $FeCo_3N$ and $NiCo_3Ni$ are 3.086 and $0.795\;{\mu}_B$, and they have the localized nature of magnetism.

Determination of a Weak Exchange Interaction in Magnetically Coupled Cluster System by EPR Singlet-Triplet Transition Lines

  • Cho, Young-Hwan;Hyunsoo So
    • Proceedings of the Korean Magnetic Resonance Society Conference
    • /
    • 2002.08a
    • /
    • pp.70-71
    • /
    • 2002
  • Exchange-coupled cluster of transition-metal ions are relevant to many different scientific areas, ranging from chemistry to solid-state physics, biology, material science and has been the subject of much research in recent years(1,2). Single crystal EPR spectroscopy works as a very effective tool for the measurement of J values for small exchange interactions. This makes EPR technique very suitable for detection of weak exchange coupling transmitted over long distances via extended atomic and melecular bridges. Large polyoxometallates (3) may provide ideal structural environments for the study of interactions between paramagnetic ions. The detailed nature of magnetic interaction (positive sign and magnitude of J~0.006 $cm^{-1}$ /) was clearly determined for di-copper(II) system by single crystal EPR spectroscopy (4). The single-triplet (S-T) transitions are forbidden by different symmetries of the wave functions. However, when the singlet ground state is mixed into triplet states, the S-T transitions can be allowed and observed as weak lines. These weak S-T lines are positioned symmetrically with respect to the main transitions in the distance equals to 2J from the center of the spectrum. This lines allow one to determine the J-value with very high accuracy when │J│ < hv 0.32 $cm^{-1}$ /. Unfortunately, the S-T transitions in the single crystal were detected by EPR method only in a few complexes until now. We have measured single-triplet transition lines for several magnetically coupled cluster systems and determined their J values accurately. The temperature dependency of J was studied by monitoring the changes in S-T.

  • PDF

Study of the Correlation of Plasma Resonance and the Refractive Index to Dielectric Dispersion in the Complex Plane

  • Zhou, Xiao-Yong;Shen, Yan;Hu, Er-Tao;Chen, Jian-Bo;Zhao, Yuan;Sheng, Ming-Yu;Li, Jing;Zheng, Yu-Xiang;Zhao, Hai-Bin;Chen, Liang-Yao;Li, Wei;Jiang, Xun-Ya;Lee, Young-Pak;Lynch, David W.
    • Journal of the Optical Society of Korea
    • /
    • v.17 no.1
    • /
    • pp.27-32
    • /
    • 2013
  • Based on the dispersive feature of the dielectric function of noble metals and the wave vector conservation in physics, both the plasma effect and the complex refractive index, which are profoundly correlated to the complex dielectric function and permeability, have been studied and analyzed. The condition to induce a bulk or a surface plasma in the visible region will not be satisfied, and there will be one solution for the real and the imaginary parts of the refractive index, restricting it only to region I of the complex plane. The results given in this work will aid in understanding the properties of light transmission at the metal/dielectric interface as characterized by the law of refraction in nature.

Mechanical and thermodynamic stability, structural, electronics and magnetic properties of new ternary thorium-phosphide silicides ThSixP1-x: First-principles investigation and prospects for clean nuclear energy applications

  • Siddique, Muhammad;Iqbal, Azmat;Rahman, Amin Ur;Azam, Sikander;Zada, Zeshan;Talat, Nazia
    • Nuclear Engineering and Technology
    • /
    • v.53 no.2
    • /
    • pp.592-602
    • /
    • 2021
  • Thorium compounds have attracted immense scientific and technological attention with regard to both fundamental and practical implications, owing to unique chemical and physical properties like high melting point, high density and thermal conductivity. Hereby, we investigate the mechanical and thermodynamic stability and report on the structural, electronic and magnetic properties of new silicon-doped cubic ternary thorium phosphides ThSixP1-x (x = 0, 0.25, 0.5, 0.75 and 1). The first-principles density functional theory procedure was adopted within full-potential linearized augmented plane wave (FP-LAPW) method. The exchange and correlation potential terms were treated within Generalized-Gradient-Approximation functional modified by Perdew-Burke-Ernzerrhof parameterizations. The proposed compounds showed mechanical and thermodynamic stable structure and hence can be synthesized experimentally. The calculated lattice parameters, bulk modulus, total energy, density of states, electronic band structure and spin magnetic moments of the compounds revealed considerable correlation to the Si substitution for P and the relative Si/P doping concentration. The electronic and magnetic properties of the doped compounds rendered them non-magnetic but metallic in nature. The main orbital contribution to the Fermi level arises from the hybridization of Th(6d+5f) and (Si+P)3p states. Reported results may have potential implications with regard to both fundamental point of view and technological prospects such as fuel materials for clean nuclear energy.

A Study on portable voice recording prevention device (휴대용 음성 녹음 방지 장치 연구)

  • Kim, Hee-Chul
    • Journal of Digital Convergence
    • /
    • v.19 no.7
    • /
    • pp.209-215
    • /
    • 2021
  • This study is a system development for voice information protection equipment in major meetings and places requiring security. Security performance and stability were secured with information leakage prevention technology through generation of false noise and ultrasonic waves. The cutoff frequency band for blocking the leakage of voice information, which has strong straightness due to the nature of the radio wave to the recording prevention module, blocks the wideband frequency of 20~20,000Hz, and the deception jamming technology is applied to block the leakage of voice information, greatly improving the security. To solve this problem, we developed a system that blocks the recording of a portable smartphone using a battery, and made the installation of a separate device smaller and lighter so that customers do not recognize it. In addition, it is necessary to continuously study measures and countermeasures for efficiently using the output of the anti-recording speaker for long-distance recording prevention.

Analysis of Domestic Heatwave Research Trends (국내 폭염 연구 동향 분석)

  • Baek, Jun-Beom;Kwon, Yongseok
    • Journal of the Society of Disaster Information
    • /
    • v.17 no.4
    • /
    • pp.755-768
    • /
    • 2021
  • Purpose: Due to the nature of heatwave research, where research is conducted for a variety of subjects and purposes, it is important to anticipate research trends and development directions in order to improve the quality of the research. Therefore, in order to provide basic data that can suggest the current status of heatwave research and the direction of future research, we tried to examine the trends of heatwave-related research. Method: Heatwave studies published in academic journals registered with the National Research Foundation of Korea from 2011 to 2020 were analyzed by classifying them according to the research period, the purpose of the study, the research subjects and the research method. Result: The main research results are as follows. First, as interest in heatwaves increases, the number of heatwave studies also increases. Second, the purpose of heatwave research is biased and needs to be studied from various perspectives. Third, although various research subjects were used, an even study was not conducted. Fourth, under the influence of the research purpose, the bias of the research method appeared together. Conclusion: The damage caused by the heat wave is persistent and has a widespread impact. In order to manage, prevent, and respond to such heat waves as disasters, equal research should be conducted in various fields.

A Study on the Improvement Plan for Reducing the Risk of Crowed Event (다중운집행사 리스크 저감을 위한 개선방안 연구)

  • Nam-Kwun Park
    • Journal of the Society of Disaster Information
    • /
    • v.20 no.2
    • /
    • pp.379-389
    • /
    • 2024
  • Purpose and Method: Crowed Events can lead to sudden accidents caused by unpredictable variables. Therefore, focusing on the '10.29 Itaewon accident' among the representative cases, we examined the accident as the process of occurrence. In addition, improvement measures were suggested through analysis of related legal systems. Result: In the Itaewon accident, a "colony wave phenomenon" occurred due to "ultra-high-density cluster stay". In addition, cluster destruction occurred from a weak location in the cluster due to clusters and pressures in different directions to avoid this. Looking at the laws related to the safety management of Crowed Events, the laws and regulations differ depending on the location and type. Due to the complementary nature of the approach to the legal blind spot, the legal system that uses similar terms of the same concept and is not systematic is causing uncertainty in the application and interpretation of the law. Conclusion: Crowd control and on-site management should be carried out for events when the cluster density is expected to reach 8 people/m2 or reached. Consistency should be maintained through the unified application of legislation to related legislation.

On the Errors of the Phased Beam Tracing Method for the Room Acoustic Analysis (실내음향 해석을 위한 위상 빔 추적법의 사용시 오차에 관하여)

  • Jeong, Cheol-Ho;Ih, Jeong-Guon
    • The Journal of the Acoustical Society of Korea
    • /
    • v.27 no.1
    • /
    • pp.1-11
    • /
    • 2008
  • To overcome the mid frequency limitation of geometrical acoustic techniques, the phased geometrical method was suggested by introducing the phase information into the sound propagation from the source. By virtue of phase information, the phased tracing method has a definite benefit in taking the interference phenomenon at mid frequencies into account. Still, this analysis technique has suffered from difficulties in dealing with low frequency phenomena, so called, wave nature of sound. At low frequencies, diffraction at corners, edges, and obstacles can cause errors in simulating the transfer function and the impulse response. Due to the use of real valued absorption coefficient, simulated results have shown a discrepancy with measured data. Thus, incorrect phase of the reflection characteristic of a wall should be corrected. In this work, the uniform theory of diffraction was integrated into the phased beam tracing method (PBTM) and the result was compared to the ordinary PBTM. By changing the phase of the reflection coefficient, effects of phase information were investigated. Incorporating such error compensation methods, the acoustic prediction by PBTM can be further extended to low frequency range with improved accuracy in the room acoustic field.