• 제목/요약/키워드: Calculated AC/A

검색결과 267건 처리시간 0.025초

Metabolism and Pharmacokinetics of S-(N,N-Diethyldithiocar-bamoyul)-N-acetyl-L-cysteine in Rats

  • Lee, Byung-Hoon;Song, Yun-Seon;Park, Jongsei;Ryu, Jae-Chun
    • Archives of Pharmacal Research
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    • 제17권6호
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    • pp.428-433
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    • 1994
  • The methabolism and phamacokinetics of a mixed disulfide S-(N, N-diethyldithiocarbamoyl)-N-acetyl-L-cysteine (AC-DDTC) were studied in rats. Two metabolites of AC-DDTC following iv and po administration were indentified in plasma and liver by HPLC and GC, namely N, N-diethyldithiocarbamate (DDTC) and the methyl ester of DDTC (Me-DDTC). AC-DDTC was very unstable in vivo and could not be detected neither in plasma nor in urine. Pharmacokinetic parameters of DDTC following intravenous administration of AC-DDTC (20 mg/kg) were calculated. DDTC has a low affinity to rat tissue and the body clearance was $9.0{\pm}3.4mkl/mim/kg$. The mean residence time (MRT) was $11.5{\pm}16.3 min$. After oral administration of 20 mg/kg AC-DDTC, maximal plasma concenttion ($C_{max}$) was $3.8{\pm}0.2 nmol/ml$ and the bioavailability was 7.04%. $C_{max}$ for DDTC at a dose of 120 mg/kg. AC-DDTC was $40.1{\pm}2.2 nmol/ml$. ART was $47.1{\pm}2.8min$.at a dose of 20 mg/kg and $110.5{\pm}6.0 min$ at 120 mg/kg.

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Current Carrying Iron Whiskers: A New Magnetic Configuration

  • Lee, J.G.;Arrott, A.S.
    • 한국자기학회지
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    • 제5권5호
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    • pp.372-375
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    • 1995
  • The magnetization pattern of the central cross section deduced from the ac susceptibility measurement is described with an analytical function. The function is based on a charge-free configuration. The thickness of the $^{\circ}$ wall lying in a (100) plane and the wall energy are calculated analytically. Total energy of the domain structure has been minimized with Ritz's method. As the result of the minimization, the energy density of the $^{\circ}$ wall lying in a (100) plane is $0.58\;erg/cm^{2}$ and the one for a (110) plane is $1.18\;erg/cm^{2}$. Thicknesses of these walls are calculated numerically. Also, the calculation indicates there is a small central domain at the cross section without applied current. With the ac susceptibility measurement the existence of the domain without current can be identified.

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태양광 인버터의 노치 필터 최적 설계 (Optimal Design of Notch Filter in Photovoltaic Inverter)

  • 김용래;허철영;이영권;최익;최주엽
    • 한국태양에너지학회 논문집
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    • 제39권2호
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    • pp.81-92
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    • 2019
  • When Photovoltaic inverter is connected to grid and used as PVPCS (Photovoltaic Power Conditioning System), 120 Hz AC ripple occurs at the dc-link capacitor voltage. This AC ripple reduces the efficiency of PVPCS and shortens the lifetime of the capacitor. In this paper, we design a notch filter to remove AC ripple. As a result, the AC voltage ripple was removed from the dc link and the THD of the PVPCS output current with the notch filter was lowered. This notch filter is determined by the damping coefficient, the bandwidth coefficient, and the switching frequency. Among these, the switching frequency determines the switching loss and the size of the LC filter, and the PVPCS with the high switching frequency has a greater efficiency loss due to the switching loss than the efficiency improvement by the notch filter. Therefore, it is important to set the optimum switching frequency in the PVPCS with the notch filter applied. In this paper, THD and switching loss of PVPCS output current with notch filter are calculated through simulation, and cost function to calculate optimum switching frequency through data is proposed.

Evaluation of the Acromioclavicular Joint Morphology for Minimizing Subacromial Erosion after Surgical Fixation of the Joint Using a Clavicular Hook Plate

  • Kim, Sung-Jae;Kee, Young-Moon;Park, Dong-Hyuck;Ko, Young-Il;Lee, Bong-Gun
    • Clinics in Shoulder and Elbow
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    • 제21권3호
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    • pp.138-144
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    • 2018
  • Background: Subacromial erosion remains a major concern after surgical fixation of acromioclavicular (AC) joint using a clavicular hook plate. To minimize postoperative subacromial erosion, we investigated the structural relationship between distal clavicle and acromion around the AC joint by considering the surgical fixation of the joint using the hook plate technique. Methods: Computed tomography scans of 101 AC joints without any inherent pathology were analyzed. The angle between the distal clavicle and acromion around the AC joint (AC angle), depth of the acromion, differences in height between distal clavicle and acromion (AC height difference), and thickness of distal clavicle and acromion at the AC joint were measured. Descriptive statistics were calculated for each anatomical parameter, and all results were compared between gender groups. Results: The mean AC angle was $17.1^{\circ}$(range, $-8.0^{\circ}$ to $39.0^{\circ}$), and the mean AC height difference was 3.5 mm (range, -0.7 to 8.7 mm). Both factors showed very high variability (coefficients of variation=62.6% and 46.6%, respectively). The mean AC angle was significantly higher in the female gender than in the male gender ($19.8^{\circ}$ vs. $13.8^{\circ}$, p=0.048). The mean acromion thickness and distal clavicular thickness were both significantly thinner in the female group than in the male group (p<0.001). Conclusions: Taken together, we believe our results might be helpful in minimizing postoperative subacromial erosion when performing surgical fixation of the AC joint using the hook plate, and be valuable in improving future design of the hook plate.

다층 고온 초전도 케이블의 전류 분포 및 교류손실 해석 (Current Distribution and Numerical Analysis of AC Losses on Multi-Layer HTS Cable)

  • 김영석;이병성;장현만;곽민환;김상현
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 추계학술대회 논문집
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    • pp.452-455
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    • 2000
  • Superconducting power cable is one of the most promising energy application of high-T$_{c}$ superconductors (HTS). A prototype HTS cable have been constructed multi-layer cable using Bi-2223 tape and tested. The AC transport losses under self field were investigated at 77K on the 19 filamentary tape and multi-layer HTS cables. And we carried out numerical analysis using bean model. The result shows that the total transport current of HTS cable in L$N_2$ was 475[A], and transport current passed through almost the outer layer (2-layer). Also, AC transport losses in outer layer of HTS cable was proportion to I$^2$ and higher than losses of inner layer. In case of Ip=Ic, calculated numerical loss density was concentrated on the edge of tape and most of loss density in cable was distributed outer layer more than inner layer. As magnetic distribution was concentrated on outer layer.r.

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Detent Force Reduction of a Tubular Linear Generator Using an Axial Stepped Permanent Magnet Structure

  • Eid Ahmad M.;Lee Hyun-Woo;Nakaoka Mutsuo
    • Journal of Power Electronics
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    • 제6권4호
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    • pp.290-297
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    • 2006
  • Various methods have been discussed to reduce detent force in a tubular permanent magnet type linear single phase AC generator. In particular, the proposed methods depend on variations of the permanent magnet construction. These methods include two approaches in the form of sloped magnets, and conical magnets in addition to the conventional method of optimizing the magnet length. The undesired detent force ripples were calculated by a two dimensional Finite Element Method (FEM). Moreover, the generated electromotive force in the stator coils was calculated for each configuration of the permanent magnet. The experimental results agreed well with those obtained from the FEM-based simulations. Sufficient reduction in the detent force was achieved over the range of 40% while the root mean square of the output voltage was maintained. It was found that sloping the permanent magnet decreased the detent force and at the same time increased the generated rms voltage of the AC generator. The performance of the designed linear AC generator was evaluated in terms of its efficiency, total weight, losses, and power to weight ratio.

요소와 암모니움 카바메이트 수용액의 FTIR 분석 (FTIR Analysis of the Aqueous Solutions of Urea and Ammonium Carbamate(AC))

  • 변홍식
    • 공업화학
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    • 제5권4호
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    • pp.657-661
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    • 1994
  • FTIR을 이용하여 암모니움 카바메이트와 요소의 혼합액은 물론, 각각의 농도를 분석하는 방법을 연구하였다. 본 연구에서는 15% w/v암모니아 용액을 용매로 이용하여 암모니움 카바메이트 수용액에서 발생하는 ammonium bicarbonate의 생성을 억제하였으며, 평형위치에 대한 오차를 1% 미만으로 유지하였다. $1600cm^{-1}$에서의 N-H bending에 의한 요소 흡수 피크와 $1405cm^{-1}$에서의 symmetric carboxylate ion stretch에 의한 암모니움 카바메이트 흡수 피크를 이용하여 보정 그래프를 그린 후 농도 계산식을 만들었다. 농도 측정간에 대한 오차는 암모니움 카바메이트에 대하여 ${\pm}0.1%$ w/v이었으며, 요소에 대하여 ${\pm}0.3%$ w/v이었다.

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Shading Coil이 장치된 전자개폐기의 흡인력에 관한 연구 (A Study on the Attracting Force of an Electromagnetic Contactor with Shading Coil)

  • 김시화;노창주
    • 한국항해학회지
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    • 제6권2호
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    • pp.35-55
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    • 1982
  • The attempt of this paper is to examine the basic theory on the analysis of the effect of a shading coil fitted to an electromagnetic contactor, and to compare experimentally the attracting force of an AC electromagnetic contactor with that of a DC electromagnetic contactor, with varying the airgap length. Equations are also proposed for calculating the AC and DC attracting force per unit consumption wattage by using the circuit constants measured from the experiment, and these calculated attracting forces are compared with those actulally measured, and then, the experimental contactor is examined in the view of its design. The calculated attracting forces are appeared to coincide well with the measured ones and the experimental contactor fitted with shading coil is revealed not so well designed for reducing the fluctuation of the attracting force.

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Determination of the Size Distribution of Magnetite Nanoparticles from Magnetic Measurements

  • Yoon, Sung-Hyun
    • Journal of Magnetics
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    • 제16권4호
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    • pp.368-373
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    • 2011
  • Particle size distributions in 10 nm magnetite ferrofluids are analyzed based on both dc and ac magnetic measurements. Modified log-normal distributions are used for fitting the experimental results, which allows for a proper account of the narrow distributions. The calculated average particle sizes are in good agreement with the TEM results. However the ac method gives a much narrower distribution width than that of the dc magnetization curve fit. The proposed measurements combined with the analysis methods are useful for the characterization of ferrofluids being considered for biomedical applications.

765 kV 교류 2회선 송전선 하의 인체 및 자동차에 유도되는 전압, 전류 계산 (Calculation of the induced voltage and current for a human and a car close to 765 kV AC double circuit transmission line)

  • 민석원;김응식;명성호;이병윤;박종근
    • 대한전기학회논문지
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    • 제45권2호
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    • pp.301-309
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    • 1996
  • This paper estimates the electric field effect near 765[kV] AC double transmission line with numerical data. The induced voltage and current of a human and car under who kinds of phase arrangement are calculated when each of two objects is insulated or grounded. When the calculated results of the low-reactance and superposition phase arrangement are compared, it is proved that the induced voltage and current of the former are about 30 [%] smaller than that of the latter. The induced current of a human and car are less than 0.5[mA] which is about 10[%] less than that of the American National Standard Code. Also the induced voltage and current of dead lines by other live lines are calculated. Finally the effective number and position of shield wires to reduce the field in ground level are considered. charge simulation method and surface charge method are used to simulate the 2 or 3 dimensional transmission line model respectively.

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