• 제목/요약/키워드: Transfer Points

검색결과 444건 처리시간 0.023초

SEPARATE AND INTEGRAL EFFECT TESTS FOR VALIDATION OF COOLING AND OPERATIONAL PERFORMANCE OF THE APR+ PASSIVE AUXILIARY FEEDWATER SYSTEM

  • Kang, Kyoung-Ho;Kim, Seok;Bae, Byoung-Uhn;Cho, Yun-Je;Park, Yu-Sun;Yun, Byoung-Jo
    • Nuclear Engineering and Technology
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    • 제44권6호
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    • pp.597-610
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    • 2012
  • The passive auxiliary feedwater system (PAFS) is one of the advanced safety features adopted in the APR+, which is intended to completely replace the conventional active auxiliary feedwater system. With an aim of validating the cooling and operational performance of PAFS, an experimental program is in progress at KAERI, which is composed of two kinds of tests; the separate effect test and the integral effect test. The separate effect test, PASCAL ($\underline{P}$AF$\underline{S}$ $\underline{C}$ondensing Heat Removal $\underline{A}$ssessment $\underline{L}$oop), is being performed to experimentally investigate the condensation heat transfer and natural convection phenomena in PAFS. A single, nearly-horizontal U-tube, whose dimensions are the same as the prototypic U-tube of the APR+ PAFS, is simulated in the PASCAL test. The PASCAL experimental result showed that the present design of PAFS satisfied the heat removal requirement for cooling down the reactor core during the anticipated accident transients. The integral effect test is in progress to confirm the operational performance of PAFS, coupled with the reactor coolant systems using the ATLAS facility. As the first integral effect test, an FLB (feedwater line break) accident was simulated for the APR+. From the integral effect test result, it could be concluded that the APR+ has the capability of coping with the hypothetical FLB accident by adopting PAFS and proper set-points of its operation.

Modelling of starch industry wastewater microfiltration parameters by neural network

  • Jokic, Aleksandar I.;Seres, Laslo L.;Milovic, Nemanja R.;Seres, Zita I.;Maravic, Nikola R.;Saranovic, Zana;Dokic, Ljubica P.
    • Membrane and Water Treatment
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    • 제9권2호
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    • pp.115-121
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    • 2018
  • Artificial neural network (ANN) simulation is used to predict the dynamic change of permeate flux during wheat starch industry wastewater microfiltration with and without static turbulence promoter. The experimental program spans range of a sedimentation times from 2 to 4 h, for feed flow rates 50 to 150 L/h, at transmembrane pressures covering the range of $1{\times}10^5$ to $3{\times}10^5Pa$. ANN predictions of the wastewater microfiltration are compared with experimental results obtained using two different set of microfiltration experiments, with and without static turbulence promoter. The effects of the training algorithm, neural network architectures on the ANN performance are discussed. For the most of the cases considered, the ANN proved to be an adequate interpolation tool, where an excellent prediction was obtained using automated Bayesian regularization as training algorithm. The optimal ANN architecture was determined as 4-10-1 with hyperbolic tangent sigmoid transfer function transfer function for hidden and output layers. The error distributions of data revealed that experimental results are in very good agreement with computed ones with only 2% data points had absolute relative error greater than 20% for the microfiltration without static turbulence promoter whereas for the microfiltration with static turbulence promoter it was 1%. The contribution of filtration time variable to flux values provided by ANNs was determined in an important level at the range of 52-66% due to increased membrane fouling by the time. In the case of microfiltration with static turbulence promoter, relative importance of transmembrane pressure and feed flow rate increased for about 30%.

MNDO Studies on Intramolecular Proton Transfer Equilibria of Acetamide and Methyl Carbamate$^1$

  • Lee, Ik-Choon;Kim, Chang-Kon;Seo, Heon-Su
    • Bulletin of the Korean Chemical Society
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    • 제7권5호
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    • pp.395-399
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    • 1986
  • Intramolecular proton transfer equilibria of acetamide and methyl carbamate have been studied theoretically by MNDO MO method. For both substrates, carbonyl-O protonated tautomer was found to be the most stable form, the next most stable one being N-protonated form. Gas phase proton transfers take place by the 1,3-proton rearrangement process and in all cases have prohibitively high activation barriers. When however one solvate water molecule participates in the process, the barriers are lowered substantially and the process proceeds in an intermolecular manner through the intermediacy of the water molecule via a triple-well type potential energy surface; three wells correspond to reactant(RC), intermediate(IC) and product complex(PC) of proton donor-acceptor pairs whereas two transition states(TS) have proton-bridge structure. General scheme of the process can be represented for a substrate with two basic centers(heteroatoms) of A and B as, $$ABH\limits^+\;+\;H_2O\;{\to}\;ABH\limits^+{\cdots}{\limits_{RC}}OH_2\;{\to}\;AB{\cdots}H\limits_{TS}^+{\cdots}{\limits_{1}}OH_2\;{\to}\;AB{\cdots}{\limits_{IC}}H\limits^+OH_2\;{\to}\;BA{\cdots}H\limits_{TS}^+{\cdots}{\limits_{2}}OH_2\;{\to}\;BA H\limits^+{\cdots}{\limits_{PC}}OH_2\;{\to}\;BAH\limits^+\;+\;H_2O$$ Involvement of a second solvate water had negligible effect on the relative stabilities of the tautomers but lowered barrier heights by 5∼6 Kcal/mol. It was calculated that the abundance of the methoxy-O protonated tautomer of the methyl carbamate will be negligible, since the tautomer is unfavorable thermodynamically as well as kinetically. Fully optimized stationary points are reported.

해양환경의 변동성을 고려한 해상풍력터빈 지지구조물의 기대수명 평가 (Expected Life Evaluation of Offshore Wind Turbine Support Structure under Variable Ocean Environment)

  • 이기남;김동현;김영진
    • 한국해양공학회지
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    • 제33권5호
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    • pp.435-446
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    • 2019
  • Because offshore structures are affected by various environmental loads, the risk of damage is high. As a result of ever-changing ocean environmental loads, damage to offshore structures is expected to differ from year to year. However, in previous studies, it was assumed that a relatively short period of load acts repeatedly during the design life of a structure. In this study, the residual life of an offshore wind turbine support structure was evaluated in consideration of the timing uncertainty of the ocean environmental load. Sampling points for the wind velocity, wave height, and wave period were generated using a central composites design, and a transfer function was constructed from the numerical analysis results. A simulation was performed using the joint probability model of ocean environmental loads. The stress time history was calculated by entering the load samples generated by the simulation into the transfer function. The damage to the structure was calculated using the rain-flow counting method, Goodman equation, Miner's rule, and S-N curve. The results confirmed that the wind speed generated at a specific time could not represent the wind speed that could occur during the design life of the structure.

격납용기 피동냉각계통내 자연순환 공기유량 및 열전달 실험연구 (An Experiment of Natural Circulated Air Flow and Heat Transfer in the Passive Containment Cooling System)

  • 류석희;오승민;박군철
    • Nuclear Engineering and Technology
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    • 제26권4호
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    • pp.516-525
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    • 1994
  • TMI 및 Chernobyl 사고이후 향후 원전에 대한 안전성 향상을 강화하기위해 개량형 원전에 대해 여러가지 피동형 안전설비가 제안되고 있다. 피동냉각계통의 타당성을 검증하고 상세 설계자료를 제공하기 위해, 본 연구는 웨스팅하우스사의 AP-600 피동격납용기와 같은 한쪽 가열면을 갖는 폐쇄유로에 대한 공기 유입구 위치 및 외부영향이 자연순환 공기유량에 미치는 영향과 자연 및 강제대류하에서 대류열전달계수를 조사하였다. 본 실험은 AP-600 격납용기를 1/26로 축소한 segment 유형의 실험장치를 토대로 수행되었다. 자연 및 강제대류 조건하의 공기유로내 특정 위치에서 공기의 속도 및 온도를 측정하였다. 실험결과는 일차원 단순 모델과 비교하였으며, 좋은 일치점을 보였다.

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중증도 분류체계를 이용한 중증도분류(Triage) (Severity of Emergency Patient classified by Triage System)

  • 배정희;손수경
    • 한국간호교육학회지
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    • 제7권2호
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    • pp.264-274
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    • 2001
  • About the patients who visited the emergency department of a hospital, investigative study was performed to assess and to classify them with triage tool, and to estimate the characteristics of them. 210 patients older than 15 years were investigated. Among them 11 patients who had responded inappropriately were excluded and remaining 210 patients were chosen as study subjects. Investigation had been performed for 30 days from Jan. 10, 2001 to Feb. 9, 2001. The triage tool was designed through the modification of triage tools developed by Kim and Choi. The data were analyzed with the SPSS program using mean, standard deviation, frequency, percentage, ANOVA and Scheffe's test. The results were as follows: 1. Of the characteristics of the study subjects, mean age of patients were 55.76 years and 70-79 years group which included 41 patients(20.6%) were most numerous. 101 (51.8%) patients visited emergency room by 119 emergency service and 91(45.7%) patients walked with assistance. 127 patients were cared in internal medicine department. 2. The distribution of triage scores were from minimum 6 points to maximum 18 points with mean $13.76{\pm}2.58$ points. 3. Triage scores had significant relationship with age(F=13.349,P=0.000), visiting method (F=8.832, P=0.000), walking status(F=28.185, p=0.000), care department(F=2.596, P=0.019), and preexisting disease(F=12.012, P=0.000). 4. After trage there were no urgent patient, 35 emergent patients(17.6%),109 subemergent patients(54.8%), and 55 nonemergent patients (27.6%). The result of emergency care were 80 admission(40.2%), 59 discharge (29.6%), 34 ICU admission(17.1%), 14 transfer to other hospital(7%), 10 operation (5%), and 2 death (2%). 5. About the time required for triage, mean duration to triage were $7.54{\pm}2.28$ mins in emergent patients, mean $7.23{\pm}2.50$ mins in subemergent patients and mean $6.49{\pm}2.19$ mins in nonemergent patients. There were no differences in duration to triage according to the severity of triage. 6. Time required in emergency treatment were mean $116.23{\pm}88.10$ in emergent patients mean $101.61{\pm}73.27$ in subemergent patients and mean $81.56{\pm}61.01$ in nonemergent patients. There were no significant difference among groups. This study depicted that triage scores were below the middle level and there were many geriatric patients in this hospital. Among the characteristics of patients, age, visiting method, walking status, care department, and accompanying disease could be data for triage of emergency patients. With triage score of a patient, the outcome of emergency care of a patient could be anticipated and this could be basal data in determining the priority of emergency nursing.

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견봉 쇄골 탈구의 봉합 나사못과 오구 견봉 인대 이전술을 이용한 오구 쇄골 인대 재건술 (Coracoclavicular Ligaments Reconstruction for Acromioclavicular Dislocation using Two Suture Anchors and Coracoacromial Ligament Transfer)

  • 신상진;노권재;정병진
    • Clinics in Shoulder and Elbow
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    • 제11권1호
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    • pp.46-52
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    • 2008
  • 목적: 본 논문은 견봉 쇄골 탈구에서 2개의 봉합 나사못과 오구 견봉 인대 이전술을 이용한 오구쇄골 인대 재건술의 소개와 임상적 결과를 알아보고자 하였다. 대상 및 방법: 40명의 환자를 대상으로 하였으며, 수술 전 방사선학적 사진에서 견봉 쇄골 탈구 환자 5명은 제3형, 4명은 제4형, 그리고 31명은 제5형이었다. 2개의 봉합 나사못을 각각 원추인대와 삼각인대의 오구 돌기 기시부에 해당하는 오구 돌기 기저부의 전외측과 후내측에 위치시켜 원위 쇄골을 오구돌기에 고정시켰으며, 오구 견봉 인대를 원위 쇄골 하면으로 이전하여 보강하였다. 결과: 평균 28개월의 추시 결과, Constant 점수는 97점으로 향상되었으며, 40명 모두 술 후 평균 3.2개월에 일상 생활로의 복귀가 가능하였다. 마지막 방사선학적 결과는 34명에서 해부학적인 정복을 보였으며, 3명은 완전 재탈구를 나타내었지만 임상적 결과는 만족할만하여 재수술을 시행하지 않았다. 또한 수상 3주 경과 후 수술한 견봉 쇄골 탈구 환자의 임상적 결과는 수상 3주 이내에 수술한 환자들과 의미 있는 차이를 보이지 않았다. 결론: 견봉 쇄골 탈구에서 2개의 봉합 나사못과 오구 견봉 인대 이전술을 이용한 오구 쇄골 인대재건술은 견봉 쇄골 관절의 물리적 안정성 얻을 수 있는 안전하고 유용한 수술 방법으로 사료된다.

농업기술정보 전달체계의 발전 방향 (Development Directions for the Agricultural Technical Information Systems)

  • 김성일;최민호
    • 농촌지도와개발
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    • 제2권2호
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    • pp.191-203
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    • 1995
  • One of the major functions of rural extension services is to transfer agricultural technologies and information, and advanced new agricultural techniques developed by research institutes, which are meaningful when they are transferred to farmers for practicl application. Information materials can be transferred in the form of newspapers, radio and television broadcasting, printed materials, audio-visual aids, and public communication networks. Agricultural information systems in the era of localization should be oriented toward county extension services, and the following points should be emphasized for more effective dissemination of agricultural technologies : 1) Central organization of the Rural Development Administration should put more emphasis on the production and dissemination of agricultural information to support activities of extension agents at the county level. 2) An Agricultural information center should be established for more effective collection, analysis, processing, production and dissemination of various agri-related information. 3) An advanced and unified network system should be adopted for more accuate and rapid information flow throughout the country, and reinforcement of manpower and facility at the county level should be emphasized for more effective dissemination of agricultural information.

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모델 가스터빈 연소기내의 자발 불안정성에 관한 실험적 연구 (An Experimental Study on the Self-excited Instabilities in Model Gas Turbine Combustor)

  • 이민철;홍정구;신현동
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2004년도 제29회 KOSCI SYMPOSIUM 논문집
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    • pp.197-205
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    • 2004
  • Most of gas turbines is operated by the type of dry premixed combustion to reduce NOx emission and economize fuel consumption. However this type operation, combustion induced instability brought failure problems cause by high pressure and heat release fluctuations. Though there has been lots of studies since Lord Rayleigh to understand this instability mechanism and control the instabilities, none of them made matters clear. In order to understand the instability phenomena, a simple experimental study with dump combustor was conducted at the moderate pressure and ambient temperature conditions. From this model gas turbine combustor self-excited instabilities at the resonance mode(200Hz) and bulk mode(10Hz) were occurred and observed at the three points of view; pressure, heat release and equivalence ratio which are acquired by peizo-electric transducer, HICCD camera and acetone LIF respectively. From this results we could see the instability mechanism clear with the account of time scale analysis which explained by the propagation of pressure wave to the upward of mixture stream and convectional transfer of the equivalence ratio fluctuation by this pressure fluctuation.

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음원을 둘러싼 인클로저 개구부를 통해 전파되는 소음의 능동 제어 (Active Control of Propagated Noise through Opening of Enclosures Surrounding a Noise Source)

  • 이한울;홍진숙;정의봉
    • 한국소음진동공학회논문집
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    • 제25권4호
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    • pp.223-231
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    • 2015
  • Enclosures are widely used to alleviate the contribution of machinery noise. It has been long concerned with the noise transmission through the access openings of the enclosures. In this study, we investigate active noise control technology for reduction of the transmission. A numerical model based on the acoustic boundary element method is first established. Using the numerical model, the acoustic transfer functions of the field points over the opening to the primary source at arbitrary locations are estimated. The feedforward control to minimize the acoustic power through the opening is then numerically implemented. The controller drives the secondary source to destructively interfere the noise transmission through the opening. Finally, a parametric study is conducted to evaluate the effects of the location and the number of the microphones on the control performance. Furthermore, the effects of the location of the secondary source on the performance of active noise control are investigated. It is followed that the control system implemented in this study leads to a significant reduction of about 31.5 dB in the sound power through the opening using only one secondary source located at the optimized position.