• 제목/요약/키워드: compound system

검색결과 1,494건 처리시간 0.03초

Aspalatone의 일반약리작용 (General Pharmacology of Aspalatone)

  • 이은방;조성익;천선아;장혜옥
    • Biomolecules & Therapeutics
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    • 제8권1호
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    • pp.99-106
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    • 2000
  • Aspalatone [3-(2-methyl-4proponyl)]-2-acetyloxybenzoate, CAS 147249-33-0) is a compound having an antithrombotic action. General pharmacological properties of aspalatone were studied. Aspalatone had no effect on central nervous system and no anticonvulsant effect up to 1200 mg/kg p.o. However, the compound has hypothermic and analgesic effect. When administered intravenously in rabbits, aspalatone did not affect blood pressure, heat rate and respiration rate and depth, and it did not inhibit transient hypotensive effect of acetylcholine. The compound did not affect isolated guinea-pig ileum and tracheal strip at a concentration of 1${\times}$$10^{-4}$, and did not inhibit histamine-induced contraction of guinea-pig ileum. It also did not affect isolated rat stomach fundus and estrogenated rat uterus at 1${\times}$$10^{-4}$, and did not inhibit contraction produced by acetylcholine or oxytocin. The pupil size and intestinal propulsion were not influenced at a large dose of was shown. The compound showed a slight increase in urine volume and led to decreased excretion of potassium in urine of rats. The results suggest that aspalatone may have no considerable adverse effects in general pharmacological aspect.

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금은화에서 분리한 Caffeic Acid의 신경세포보호 활성 (Neuroprotective Activity of Caffeic Acid Isolated from Lonicera japonica)

  • 손예림;마충제
    • 생약학회지
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    • 제51권1호
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    • pp.30-35
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    • 2020
  • We previously reported that caffeic acid isolated from Lonicera japonica showed potent neuroprotective activities against glutamate injured neuronal cell death in primary cortical cells. In this study, we tried to confirm the neuroprotective activity in glutamate injured HT22 cells and elucidate mechanisms of neuroprotective action of caffeic acid. We used glutamate induced HT22 cell death as a bioassay system. The compound decreased reactive oxygen species increased by high concentration of glutamate treatment in HT22 cells. Also, Ca2+ concentration was decreased by this compound. This compound made mitochondrial membrane potential maintain to normal condition. This also affected anti-oxidative enzymes and glutathione contents. Treatment of this compound increased not only glutathione reductase and peroxidase to the control level and also amount of glutathione, an endogeneous antioxidant. These experimental results showed that caffeic acid isolated from L. japonica exerted potent neuroprotective activity through the anti-oxidative pathway.

Angle-sensitive Pixels Based on Subwavelength Compound Gratings

  • Meng, Yunlong;Hu, Xuemei;Yang, Cheng;Shen, Xinyu;Cao, Xueyun;Lin, Lankun;Yan, Feng;Yue, Tao
    • Current Optics and Photonics
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    • 제6권4호
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    • pp.359-366
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    • 2022
  • In this paper, we present a new design for angle-sensitive pixels (ASPs). The proposed ASPs take advantage of subwavelength compound gratings to capture the light angle, which enables pixel size to reach the wavelength scale of 0.7 ㎛ × 0.7 ㎛. The subwavelength compound gratings are implemented by the wires of the readout circuit inherent to the standard complementary metal-oxide-semiconductor manufacturing process, thus avoiding additional off-chip optics or post-processing. This technique allows the use of two pixels for horizontal or vertical angle detection, and can determine the light's angle in the range from -45° to +45°. The proposed sensor enables surface-profile reconstruction of microscale samples using a lensless imaging system.

조선 세종대 삼물회(三物灰) 도입에 따른 석실릉 구조개선과 의의 (A study on the significance and structural improvement of the stone chamber tomb by the application of a compound lime - Mortar during the reign of king Sejong in the Joseon Dynasty)

  • 신지혜
    • 헤리티지:역사와 과학
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    • 제55권1호
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    • pp.223-242
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    • 2022
  • 본 연구는 세종대에 삼물회를 조선왕릉에 도입하게 되는 과정을 살펴보고, 1446년(세종 28년) 영릉의 구조적 변화가 갖는 의미를 살펴보는 데 중점을 두었다. 조선초 왕릉은 고려의 석실릉을 답습하여 조성하였다. 조선왕릉으로 처음 지어진 신덕왕후의 정릉은 고려의 공민왕과 노국공주의 정릉·현릉을 건립한 경험을 갖고 있는 김사행이 주도적으로 건립하였다. 이후 박자청이 이어받아 조선 초 석실릉을 건립하였으므로, 고려의 석실구조를 기반으로 조선왕릉이 조성되었다고 보는 것이 적절할 것이다. 그러나 성종대의 『국조오례의』에 기록된 석실의 구조를 살펴보면 고려의 것과는 매우 다르다. 뿐만 아니라 『세종실록』에 기록된 태종과 원경왕후의 석실제도와도 다르다. 가장 큰 차이는 석실에 삼물회를 도입하여 구조적인 보강을 시도하였다는 점이다. 이러한 변화는 1446년(세종 28년) 소헌왕후의 국상으로 영릉(英陵)을 건립할 때, 석실 내에 물이 스며들거나 고이지 않는 밀실한 구조를 만들고자 했던 세종의 의지를 반영한 것이다. 1446년 세종과 소헌왕후의 합장릉으로 조성된 영릉(英陵)과 1452년에 조성된 문종의 현릉(顯陵)은 석실구조 바깥에 삼물회격을 추가로 시공한 석실과 회격의 복합구조체이다. 이것은 1468년(예종 즉위년) 세조의 유교에 따라 석실을 폐지하고 회격만으로 현궁을 만드는데 구조적 기반이 되었다. 즉, 영릉과 현릉의 구조에서 내부의 석실구조를 제거하고, 바깥의 회격만을 시공함으로써 회격 현궁이 조성된 것이다. 이로써 조선왕릉은 『국조오례의』에 기록된 석실과 회격의 복합 구조체인 회격석실릉에서, 석실을 제거하고 회격만을 조성하는 회격릉으로 정착하게 된다. 이러한 전개과정을 살펴볼 때, 1446년(세종 28)에 삼물회로 만든 회격구조를 석실에 결합한 회격석실릉은 조선만의 특별한 석실구조이며, 조선왕릉의 지하구조가 회격릉으로 변천하게 되는 기반이 되었음을 논증한다.

복합 유성 기어로 구성된 하이브리드 시스템 효율 분석 (Analysis of the Efficiency of the Compound-split Hybrid Systems)

  • 김남욱;양호림;조성태;박영일;차석원
    • 한국자동차공학회논문집
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    • 제15권5호
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    • pp.118-124
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    • 2007
  • The efficiency of the hybrid systems which are composed of compound planetary gear sets depend on the amount of the recirculating energy among the motors and battery. This paper studies the analysis of the system efficiency with the parameters, ${\alpha},\;{\beta},\;{\gamma_a},\;{\gamma_b}$ and $\gamma_s$. The efficiency of the systems and the relative torque, speed and power of the power resources are represented by these parameters. The recuperating parameter $\kappa$ which makes the systems generalized is introduced, so the efficiencies of the modes such as the hybrid mode, the engine mode, the motoring mode and the recuperating mode are analyzed with simple equations. The tendency of the system efficiency according to the variations of the $\gamma_s$ and $\kappa$ are studied, by which it can be possible to reduce the loss of the power because the strategies for avoiding the singular speed ratio $\gamma_s$ are helpful for the system efficiency and specific value of $\kappa$ can increase the efficiency of the systems.

대형 Community 건물의 연료전지 구동 복합열원 하이브리드 히트펌프 시스템 성능에 관한 해석적 연구 (Study on the Performance of Fuel Cell Driven Compound Source Heat Pump System to a Large Community Building)

  • 정동화;변재기;최영돈;조성환
    • 신재생에너지
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    • 제4권3호
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    • pp.23-35
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    • 2008
  • In the present study, performances of fuel cell driven compound source hybrid heat pump system applied to a large community building are simulated. Among several renewable energy sources, ground, river, sea, and waste water sources are chosen as available alternative energies. The performance and energy cost are varied with the hybrid heat pump sources. The system design and operation process appropriate for the surrounding circumstance guarantee the high benefit of the heat pump system applied to a large community building. Th system is driven by fuel cell system instead of the late-night electricity due to the advantages of the low energy cost and waste heat with high temperature.

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복합포아송 수요를 가지는 CONWIP 시스템에서 고객집단의 성능평가 (Order Based Performance Evaluation of a CONWIP System with Compound Poisson Demands)

  • 박찬우;이효성
    • 한국경영과학회:학술대회논문집
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    • 한국경영과학회 2004년도 추계학술대회 및 정기총회
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    • pp.8-12
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    • 2004
  • In this study we consider a CONWIP system in which the processing times at each station follow a Coxian distribution and the demands for the finished products arrive according to a compound Poisson process. The demands that are not satisfied are backordered according to the number of demands that exist at their arrival instants. For this system we develop an approximation method to calculate order based performance measures such as the mean time of fulfilling a customer order and the mean number o: customer orders. For the analysis of the proposed CONWIP system, we model the CONWIP system as a closed queueing network with a synchronization station and analyze the closed queueing network using a product form approximation method. Numerical tests show that the approximation method provides fairly good estimation of the performance measures of interest.

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Ab Initio and Experimental Studies on Dibenzothiazyl-Disulfide

  • Jian, Fang-Fang;Zhang, Ke-Jie;Zhao, Pu-Su;Zheng, Jian
    • Bulletin of the Korean Chemical Society
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    • 제27권7호
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    • pp.1048-1052
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    • 2006
  • Ab initio calculations of the structure, atomic charges and natural bond orbital (NBO) have been performed at HF/6-311G** and B3LYP/6-311G** levels for the title compound of dibenzothiazyl-disulfide. The calculated results show that the two nitrogen atoms have the biggest negative charges and they are the potential sites to react with the metallic ions, which make the title compound become a di-dentate ligand. Vibrational frequencies of the title compound have been obtained and compared with the experimental value and the comparison indicates that B3LYP/6-311G** level is better than HF/6-311G** level to predict the vibrational frequencies for the system studied here. For the title compound, electronic absorption spectra calculated by time?ependent density functional theory (TD-DFT) are more accurate than Hartree-Focksingle-excitation CI (CI-Singles) method. NBO analyses show that the electronic transitions are mainly derived from the contribution of bands $\pi\rightarrow\pi^{*}$. Thermodynamic calculated results show that the formation of the title compound from 2-mercaptobenzothiazole is a spontaneous process at room temperature with the change of free Gibbs being negative value.

Investigation of Al-hydroxide Precipitate Fouling on the Nanofiltration Membrane System with Coagulation Pretreatment: Effect of Inorganic Compound, Organic Compound, and Their Combination

  • Choi, Yang-Hun;Kweon, Ji-Hyang
    • Environmental Engineering Research
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    • 제16권3호
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    • pp.149-157
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    • 2011
  • Nanofiltration (NF) experiments were conducted to investigate fouling of Al-hydroxide precipitate and the influence of organic compound, inorganic compound, and their combination, i.e., multiple foulants. $CaCl_2$ and $MgSO_4$ were employed as surrogates of inorganic compounds while humic acid was used as surrogate of organic compound. The flux attained from NF experiments was fitted with the mathematical fouling model to evaluate the potential fouling mechanisms. Al-hydroxide fouling with a cake formation mechanism had little effect on the NF membrane fouling regardless of the Al concentration. The NF fouling by Al-hydroxide precipitate was deteriorated in presence of inorganic matter. The effect of Mg was more critical in increasing the fouling than Ca. This is because the Mg ions enhanced the resistances of the cake layer accumulated by the Al-hydroxide precipitate on the membrane surfaces. However, the fouling with Mg was dramatically mitigated by adding humic acid. It is interesting to observe that the removal of the conductivity was enhanced to 61.2% in presence of Mg and humic acid from 30.9% with Al-hydroxide alone. The influence of dissolved matter (i.e., colloids) was more negative than particulate matter on the NF fouling for Al-hydroxide precipitate in presence of inorganic and organic matter.

혼합형 디지털 자동 전압 조정 장치를 이용한 선박용 동기발전기의 출력전압제어 (Voltage Control of a Synchronous Generator for Ship using a Compound Type Digital AVR)

  • 박상훈;이상석;유재성;이수원;원충연
    • 전기학회논문지P
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    • 제58권4호
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    • pp.397-403
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    • 2009
  • In this paper, an exciter current control of a synchronous generator for ships using a compound type digital automatic voltage regulator (DVAR) in order to provide a constant output voltage of the generator is presented. The compound type DAVR is composed of a controller part to adjust output voltage and an power source unit to supply power to the exciter. The controller part, which generates the PWM switching pattern via the PI controller, drives a power MOSFET for bypass to limit the SG's exciter current. The power source unit part is parallel connected to an output terminal of the generator through a reactor and a power CT. The residual magnetic flux of SG provides exciter current to the exciter through the reactor during the initial running or no load state and load current supplies field current to the exciter through the power CT during loading state. This paper confirmed an experiment to verify the validity of compound type DAVR system for controlling output voltage of synchronous generator.