• 제목/요약/키워드: Rpf

검색결과 112건 처리시간 0.024초

${\alpha}_2-Adrenergic$ Receptor 차단제인 Idazoxan의 신장작용 (Renal Action of Idazoxan, ${\alpha}_2-Adrenergic$ Antagonist, in Dog)

  • 고석태;강경원
    • Biomolecules & Therapeutics
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    • 제8권2호
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    • pp.132-139
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    • 2000
  • This study was performed far investigation of influence on renal function of idazoxan, $\alpha_{2}$-adrenergic antagonist, using the dog. Idazoxan, when giver. into vein, produced the decrease of urine volume(vol) accompanied with the reduction of free water clearance($C_{H2O}$), amounts of sodium excreted in urine($E_{Na}$), with the increase of potassium excreted in urine($E_{K}$), and so ratios of potassium against sodium($K^{+}/Na^{+}$) were elevated, at this time, greatened reabsorption rate of sodium and diministered that of potassium in renal tubules were appeared. Idazoxan administered into a renal artery elicited the augmentation of vol, glomerular filtration rate(GFR), renal plasma flow(RPF) and no change of filtration fraction(FF) in only ipsilateral kidney, whereas $E_{Na},\;E_{K}\;and\;K^{+}/Na^{+}$ were increased and $C_{H2O}$ was decreased in both control and experimental kidney. Idazoxan given into carotid artery showed partial increased vol, remarkable expanded RPF and unchanged GFR, and so filtration fraction(FF) was markedly reduced. Above results suggest that anti- diuretic action of idazoxan given into vein is mediated by reduction of $C_{H2O}\;and\;E_{Na}$, diuretic action only in the ipsilateral kidney by idazoxan given into a renal artery is caused by hemodynamic improvement through expansion of vas afferens in glomeruli.

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니트릭옥사이드의 합성 억제제인 $N^G$-니트로-L-아르기닌의 신장작용 (Renal Action of $N^G$-Nitro-L-arginine, Nitric Oxide Synthase Inhibitor, in Dog and Rabbit)

  • 고석태;유강준;황명성
    • 약학회지
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    • 제42권5호
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    • pp.519-526
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    • 1998
  • This study was performed in order to investigate the effect of renal function of NG-nitro-L-arginine (L-NOARG), inhibitor of nitric oxide (NO) synthase, in dog and ra bbit. L-NOARG, when given intravenously in dogs, exhibited the decrease in urine flow (vol), renal plasma flow (RPF), osmolar clearance ($C_{osm}$) and amounts of sodium and potassium excreted in urine($E_{Na},\;E_K$). These renal functions of L-NOARG showed the same aspect in rabbit, too. L-NOARG, when administered into a renal artery, showed the same pattern as was obtained when given intravenously in both experimental and control kidney in dog. L-NOARG administered into the carotid artery showed the decrease in Vol, RPF, $E_{Na}$, in a low doses that did not show any effect when given intravenously. Above results suggest that L-NOARG produces antidiuretic action in dog and rabbit, and these antidiuretic actions may be mediated by central action.

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페로니켈 공정의 석탄대체 물질에 대한 열정산 (Heat Balance for the coal substitute materials in the Ferronickel manufacturing process)

  • 김희열
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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    • pp.161.2-161.2
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    • 2010
  • 페로니켈 제조 공정에 있어서 석탄의 비중은 총 에너지원 중 70%에 상당하며, 온실가스 배출 또한 65%에 달한다. 이에 석탄을 대체할 물질로서 RPF, RDF, Biomass, TDF 등을 고려하였으며, 자체 개발한 열정산 프로그램을 활용하였다. 해석결과 석탄 대체물질의 사용할 경우 페로니켈 제조공정의 에너지 비용을 상당량 저감할 수 있을 것으로 기대된다.

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HCCI 조건에 일어나는 희박 PRF/공기 혼합물의 점화특성에 관한 직접수치모사 연구 (A DNS Study of Ignition Characteristics of Lean PRF/Air Mixtures under HCCI Conditions)

  • ;유춘상
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2012년도 제45회 KOSCO SYMPOSIUM 초록집
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    • pp.153-156
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    • 2012
  • Direct numerical simulations (DNSs) of ignition of lean primary reference fuel (PRF)/air mixtures under homogeneous charge compression ignition (HCCI) conditions are performed using 116-species reduced chemistry. The influence of variations in the initial temperature field, imposed by changing the variance of temperature, and the fuel composition on ignition of lean PRF/air mixtures is studied using the displacement speed analysis.

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상정사고를 고려한 ATC 계산에 관한 연구 (A Study on the Available Transfer Capability(ATC) calculation with Contingency)

  • 정성원;황건호;김양일;김재현
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2008년도 제39회 하계학술대회
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    • pp.296-297
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    • 2008
  • This paper proposed a methods to ATC calculation using energy function. In this paper, ATC was calculated as PTDF, LODF, RPF and Energy Function method and calculation results of each methods was compared. Contingency ranking method decided the overloading branches by PI-index. As a result, a study proved the fast and accurate ATC calculation method considering contingency suggested in this paper.

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고비중(高比重) 종말품(終末品) 폐(廢)플라스틱 대량처리(大量處理)를 위한 마찰하전(摩擦荷電) 정전선별(靜電選別) 기술개발(技術開發) (Development of Tribo-electrostatic Separation Technique for Scale-up Process of Heavy Group Plastic Tailings)

  • 박철현;전호석;백상호;김병곤
    • 자원리싸이클링
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    • 제18권2호
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    • pp.30-38
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    • 2009
  • 습식 비중선별에서 sink products로 회수된 종말품 고비중 폐플라스틱 산물의 재활용을 위한 마찰하전정전선별 실증화 연구를 수행하였다. 종말품 고비중 폐플라스틱의 재질분리에 있어 적합한 하전물질 선정을 위한 하전특성 연구결과, high density polyethylene (HDPE)재질이 가장 효과적인 하전물질로 규명되어, 이 재질을 이용하여 하전장치를 제작하였다. 실험결과 최적조건인 전극의 전기장 250 kV/m, 분리대의 위치 (-) 8 cm, 그리고 상대습도 40%이하에서 PET, PS and others 산물의 품위와 회수율이 각각 99.1%와 86.0%인 결과를 얻었다. 또한 300 kg/h 규모의 대량처리 기술을 개발하여 종말품 폐플라스틱을 2등급 이상의 RPF나 RDF로 재활용할 수 있는 즉, PVC를 1% 미만을 줄일 수 있는 선별기술을 개발하였다.

폐비닐을 이용(利用)한 재생원료화(再生原料化) 기술(技術) (Feedstock Recycling Technologies using Waste Vinyls)

  • 정수현;나정걸;김상국;우희명;김영태
    • 자원리싸이클링
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    • 제22권4호
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    • pp.46-54
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    • 2013
  • 국내에서 발생하는 폐플라스틱의 양은 폐비닐류를 포함하여 연간 500만톤에 이르며 이 가운데 재활용 선별장을 통하여 배출되는 폐비닐류의 양은 연간 100만톤 정도에 이르는 것으로 추정되고 있다. 재활용 선별장의 폐비닐류는 RPF(Refuse Plastic Fuel) 또는 재생원료로 전환되어 재활용이 이루어지고 있다. 본 연구에서는 재활용 선별장에서 발생하는 폐비닐을 열매체 가열공정에 의하여 용융처리하여 재생 폐비닐 원료로서 이용가능성을 인장강도를 통하여 분석하고 기존의 재생품과 비교함으로서 용융재생원료의 이용 가능성을 판단하였다. 상업용으로 사용하기 위해서는 폐비닐류를 이용한 재생원료의 인장강도는 100 $kgf/cm^2$ 정도가 적합함을 알 수 있었다.

An improved regularized particle filter for remaining useful life prediction in nuclear plant electric gate valves

  • Xu, Ren-yi;Wang, Hang;Peng, Min-jun;Liu, Yong-kuo
    • Nuclear Engineering and Technology
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    • 제54권6호
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    • pp.2107-2119
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    • 2022
  • Accurate remaining useful life (RUL) prediction for critical components of nuclear power equipment is an important way to realize aging management of nuclear power equipment. The electric gate valve is one of the most safety-critical and widely distributed mechanical equipment in nuclear power installations. However, the electric gate valve's extended service in nuclear installations causes aging and degradation induced by crack propagation and leakages. Hence, it is necessary to develop a robust RUL prediction method to evaluate its operating state. Although the particle filter(PF) algorithm and its variants can deal with this nonlinear problem effectively, they suffer from severe particle degeneracy and depletion, which leads to its sub-optimal performance. In this study, we combined the whale algorithm with regularized particle filtering(RPF) to rationalize the particle distribution before resampling, so as to solve the problem of particle degradation, and for valve RUL prediction. The valve's crack propagation is studied using the RPF approach, which takes the Paris Law as a condition function. The crack growth is observed and updated using the root-mean-square (RMS) signal collected from the acoustic emission sensor. At the same time, the proposed method is compared with other optimization algorithms, such as particle swarm optimization algorithm, and verified by the realistic valve aging experimental data. The conclusion shows that the proposed method can effectively predict and analyze the typical valve degradation patterns.

Effect of Finger Profile on Static Bending Strength Performance of Finger-Jointed Wood

  • Park, Han-Min;Lee, Gyun-Pil;Kong, Tae-Suk;Ryu, Hyun-Soo;Byeon, Hee-Seop
    • Journal of the Korean Wood Science and Technology
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    • 제32권6호
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    • pp.57-66
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    • 2004
  • To study the efficient usage of small diameter logs and woods containing defects such as knots, slope of the grain and decay, six types of finger-jointed woods with various finger profiles were made of poplar, pine and oak with different density. We investigated the effect of finger profile on static bending strength performances of finger-jointed woods. The efficiency of bending MOE, MOR and deflection showed the highest value in poplar finger-jointed wood with the lowest density of three species, and the lowest value in oak finger-jointed wood with the highest density of three species. The values markedly decreased with increasing finger pitch for finger-jointed wood glued with polyvinyl acetate (PVAc) resin for all tested species, whereas for the finger-jointed wood glued with resorcinol-phenol formaldehyde (RPF) resin, the influence of finger pitch on the efficiency of MOE was not found in all tested species, and those on the efficiency of MOR and deflection indicated the same trend as finger-jointed wood glued with PVAc resin in the case of pine and oak finger-jointed wood with higher densities. It was found that the values tended to decrease with increasing density of species on the whole and the desirable finger pitches were L (6.8 mm) for poplar, M (4.4 mm) for pine and S (3.5 mm) for oak in a view of economy. For finger-jointed wood glued with PVAc resin, the fitness between a tip and a root width of a pair of fingers δ of 0.5 mm indicated the highest efficiency of MOE for all species. And, the influence of δ on MOR was only found in oak finger-jointed wood glued with RPF resin and the desirable δ value for oak was 0.1 mm. However, it was found that the influence of δ on the strength performance was very small.

Performance Comparison of GA, DE, PSO and SA Approaches in Enhancement of Total Transfer Capability using FACTS Devices

  • Chandrasekar, K.;Ramana, N.V.
    • Journal of Electrical Engineering and Technology
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    • 제7권4호
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    • pp.493-500
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    • 2012
  • In this paper the performance of meta-heuristics algorithms such as GA (Genetic Algorithm), DE (Differential Evolution), PSO (Particle Swarm Optimization) and SA (Simulated Annealing) for the problem of TTC enhancement using FACTS devices are compared. In addition to that in the assessment procedure of TTC two novel techniques are proposed. First the optimization algorithm which is used for TTC enhancement is simultaneously used for assessment of TTC. Second the power flow is done using Broyden - Shamanski method with Sherman - Morrison formula (BSS). The proposed approach is tested on WSCC 9 bus, IEEE 118 bus test systems and the results are compared with the conventional Repeated Power Flow (RPF) using Newton Raphson (NR) method which indicates that the proposed method provides better TTC enhancement and computational efficacy than the conventional procedure.