• Title/Summary/Keyword: Recovery period

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Dynamic Simulation of Heat Recovery Steam Generator (폐열회수 보일러의 동특성 시뮬레이션)

  • Lee, Ki-Hyun;Lee, Dong-Su;Cho, Chang-Ho
    • Proceedings of the KSME Conference
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    • 2001.11b
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    • pp.847-852
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    • 2001
  • A thorough understanding of the transient behavior during load following and start-up is essential in the design and operation of an heat recovery steam generator(HRSG). During this period of time, material that is exposed to high temperature and experiences a large temperature variation is subject to high thermal stress. APESS(Advanced Plant Engineering & Simulation System) is a dynamic simulation software for power plant which is under being developed by Doosan Heavy Industries & Construction Co., Ltd. This paper present the introduction of APESS and the result of simulation for an heat recovery steam generator.

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Alkaline Protease of a Genetically-Engineered Aspergillus oryzae for the Use as a Silver Recovery Agent from Used X-Ray Film

  • Samarntarn, Warin;Morakot Tanticharoen
    • Journal of Microbiology and Biotechnology
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    • v.9 no.5
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    • pp.568-571
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    • 1999
  • Aspergillus oryzae U1521, which was a genetically engineered strain, produced 1,000,600 U per g . glucose of extracellular alkaline protease within 72 h in a submerged fermentation. However, the alkaline protease was not detected during the first 24 h. Northern blot analysis indicated that the enzyme synthesis was repressed at the transcriptional level during the lag period. Both catabolite repression and pH of the growth medium significantly affected the enzyme production. Use of this enzyme as a silver recovery agent from used X-ray film was confirmed by experiments in the shake-flask scale.

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Consideration on the Preparation of Current Meters for Deep-sea Mooring and Cause of Mooring Recovery Failures (유속계 심해계류 준비 및 유속계 회수 실패원인에 관한 고찰)

  • Hwang, Sang-Chul
    • Ocean and Polar Research
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    • v.30 no.2
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    • pp.207-213
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    • 2008
  • An interest in deep-sea measurements has been gradually increased in association with global warming and the need for deep-sea resources development. Long-term mooring of current meters has been recently conducted primarily for these purposes. In general, current meters equipped on a mooring line are deployed and recovered for a planned period in the sea. This paper describes all the preparations for deep-sea mooring. It also reviews the possible causes of the failures of recovery, which occasionally happens in the sea.

Influence of polymer coating on SFCL recovery under load

  • Gorbunova, D.A.;Kumarov, D.R.;Scherbakov, V.I.;Sim, Kideok;Hwang, Soon
    • Progress in Superconductivity and Cryogenics
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    • v.21 no.4
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    • pp.44-47
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    • 2019
  • This paper is a study of recovery under load process of superconducting fault current limiter (SFCL). SFCL consists of five parallel-connected high-temperature superconductor (HTS) tapes additionally stabilized by stainless tape. Previously, HTS was heated by current pulse to simulate a short circuit in a power grid. During the cooling period, the current amplitude decreased to 23% or less of HTS critical current value, which is the simulation of network re-switching. When HTS with a polymer coating is cooled, temperature gradient on thermal insulation layer occurs, that prevents a boiling crisis and improves the heat sink into liquid nitrogen. Two samples are coated with a 30 ㎛ and 50 ㎛ polylactide (PLA) layers, reference sample has no polymer coating on it. Samples with a polymer coating show 3-5 times faster cooling than the reference one.

Radioprotective Effects of Ginseng Proteins (인삼단백질의 방사선 방어작용)

  • 김춘미;한규선
    • YAKHAK HOEJI
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    • v.29 no.5
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    • pp.246-252
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    • 1985
  • Ginseng proteins were isolated and partially purified to obtain two fractions, namely GI and GII. Radioprotective effects of these fractions were examined on $\gamma$-ray irradiated ICR mice by observing 30-day survival rates after irradiation. Also investigated were the effects of GI fraction on the recovery of radiation damage. As the results, the GI fraction showed strong protection against radiation indicated by the increment of 30-day survival rates, while the GII fraction did not. The GI fraction enhanced the recovery of body and splenic weights and increased the amount of DNA in liver significantly. It also helped to recover the damage done on erythrocytes by increasing the number to normal in short period, however, it had no effect on the recovery of leukocyte counts.

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Stability characteristics of DyBCO coated conductor stabilized with stainless steel

  • Dixit, Manglesh;Kim, Tae-Hyung;Oh, Sang-Soo;Song, Kyu-Jeong;Kim, Ho-Min;Park, Kwon-Bae
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.07a
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    • pp.288-289
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    • 2005
  • As high temperature superconductor applications became a reality due to increase in coated conductor performance, it is important to understand their stability behavior to design safe electrical power systems. We have experimentally studied the dependence of quench and recovery characteristics of coated conductors on the amplitude of current and duration time. The sample used in the present study is stabilized with stainless steel. Stability tests of 3 cm long sample were performed in a liquid nitrogen bath cooling condition by applying a short period over current pulses for 50 and 100 ms, with amplitude up to ~ 6 times of the critical current. The transport current that follows before and after the current pulse was fixed about ~85% the critical current. We analyzed the quench recovery using the current voltage characteristic.

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Effects of Prostacyclin [PGI2] on Myocardial Protection in the Isolating Working Heart Model (적출활동심장에서 Prostacyclin [PGI2]의 심근보호효과)

  • Lee, Gil-No;Kim, Gyu-Tae
    • Journal of Chest Surgery
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    • v.20 no.4
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    • pp.643-654
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    • 1987
  • The effect of prostacyclin[PGI, ] on myocardial preservation during global ischemia was studied in the isolating working rabbit heart model. Forty hearts underwent a 15 minute period of retrograde nonworking perfusion with Krebs-Henseleit buffer solution [37*C] and were switched over to the working mode for 15 minutes. After baseline measurement of heart rate, peak aortic pressure, aortic flow, and coronary flow, all hearts were subjected to 60 minutes of ischemic arrest at 10*C induced with St. Thomas Hospital cardioplegic solution: Group I had single dose cardioplegia, Croup II double dose, Croup III oxygenated double dose, and Group IV single dose with PCI, infusion [10ng/min./gm heart weight]. Hearts were then revived with 15 minute period of nonworking reperfusion at normothermia, followed by 30 minutes of working perfusion. Repeat measurements of cardiac function were obtained and expressed as a percent of the preischemic baseline values. Oxygen content of arterial perfusate and coronary effluent was measured by designed time interval. Leakage of creatine kinase was determined during post-ischemic reperfusion period. Finally wet hearts were weighed and placed in 120*C oven for 36 hours for measurement of dry weight. In the PGI, treated group [IV], heart rate increased consistently throughout the period of reperfusion from 100*5.0% [p<0.001] to 107*6.2% [p<0.001]. The percent recovery of aortic flow showed 95*5.7% [p<0.001] at the first 3 minute and full recovery through the subsequent time. Coronary flow was augmented significantly in the 3 minute [96*6.2%, p<0.001] and then sustained above baseline values. Among the Croup I, II, and III, all hemodynamic values were significantly below preischemic levels. PGI2 relatively increased oxygen delivery [1.22*0.19ml/min, p<0.001] and myocardial oxygen consumption [0.90*0.13ml/min, p<0.001] during reperfusion period. Leakage of creatine kinase in the PGI2 group was 9.3*1.58IU/15min [p<0.001]. This was significantly lower than Group I [33.0*2.68 IU/15min]. The water content of PCI2 treated hearts [81*0.9%, p<0.001] was also lower than the other groups.

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Effect of Regular Exercise during Recovery Period Following Steroid Treatment on the Atrophied Type II Muscles Induced by Steroid in Young Rats (스테로이드 치료 후 회복기의 규칙적인 운동이 어린 쥐의 스테로이드 유발성 위축 Type II 근육에 미치는 영향)

  • 최명애;신기수;안경주;최정안;이윤경
    • Journal of Korean Academy of Nursing
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    • v.32 no.4
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    • pp.550-559
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    • 2002
  • This study was conducted to determine whether low intensity regular exercise following dexamethasone treatment could attenuate steroid-induced muscle atrophy. Method: 36 Wistar-rats(90-110g) were divided into six groups: control group(C), dexamethasone treatment group(D), sedentary group after normal sedentary period(C+S), sedentary group after dexamethasone treatment period(D+S), exercise group after normal sedentary period(C+E), and excercise group after dexamethasone treatment period(D+E). D, D+S, and D+E groups received dexamethasone injection(5mg/Kg) for seven days whereas C, C+S, and C+E groups received normal saline injection. Both C+E and D+E groups ran on a treadmill for 60 minutes/day(20minutes/4hours) at 15m/min and a 10$^{\circ}$grade for seven recovery days. Result: Post-weight(body weight before muscle dissection) of D group significantly decreased by 16.03%, and that of D+E group significantly increased by 15.51% compared with pre-weight(body weight before steroid treatment). TypeII muscle(plantaris and gastrocnemius) weights of D group were significantly lower than those of C group. Myofibrillar protein contents of typeII muscles of D group tended to decrease comparing with C group. In D+E groups, body weights and relative weights of typeII muscles(muscle weight(mg)/post-weight(g)) tended to increase comparing with D+S group. Conclusion: It is suggested that steroid- induced muscle atrophy can be ameliorated through low intensity regular exercise after dexamethasone treatment.

Dynamics of Facial Subcutaneous Blood Flow Recovery in Post-stress Period

  • Sohn, Jin-Hun;Estate M. Sokhadze;Lee, Kyung-Hwa;Lee, Jong-Mi;Park, Mi-Kyung;Park, Ji-Yeon
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 2000.11a
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    • pp.62-68
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    • 2000
  • The aim of the study was to compare effects of music and white noise on the recovery of facial blood flow parameters after stressful visual stimulation. Twenty-nine subjects participated in the experiment. Three visual stimulation sessions with aversive slides (the IAPS, disgust category) were followed by subjectively "pleasant" (in the first session), "sad" music (in the second ), and white noise (in the third ). Order of sessions was counterbalanced. Blood flow parameters (peak blood flow, blood flow velocity, blood volume) were recorded by Laser Doppler single-crystal system (LASERFLO BPM 403A) interfaced through BIOPAC 100WS with AcqKnowledge software (v.3.5) and analyzed in off-line mode. Aversive visual stimulation itself decreased blood flow and velocity in all 3 sessions. Both "pleasant" and "sad" music led to the restoration of baseline levels in all blood flow parameters, while noise did not enhance recovery process. Music on post-stress recovery had significant change in peak blood flow and blood flow velocity, but not in blood volume measures. Pleasant music had bigger effects on post-stress recovery in peak blood flow and flow velocity than white noise. It reveals that music exerted positive modulatory effects on facial vascular activity measures during recovery from negative emotional state elicited by stressful slides. Results partially support the undoing hypothesis of Levenson (1994), which states that positive emotions may facilitate process of recovery from negative emotions.

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A Study on the Upset Prevention & Recovery Training Method for Navy Fixed Wing Pilots Using P-3 Simulator (P-3C 시뮬레이터를 활용한 해군 고정익조종사 UPRT 훈련 방안에 대한 연구)

  • Jung-bong Lee
    • Journal of Advanced Navigation Technology
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    • v.27 no.3
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    • pp.293-299
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    • 2023
  • UPRT(Upset Prevention And Recovery Training) is an accident prevention training program developed over a three-year period after the main cause of aircraft accidents in commercial aviation between 2001 and 2011 was analyzed as LOC-I(Loss Of Control Flight). In 2014, ICAO presented UPRT for fixed-wing aircraft through Doc.10011(Manual On Aeroplane Upset Prevention And Recovery Training) and recommended mandatory implementation to Contracting States from March 2019. Since naval P-3C is a major mission of maritime patrol and anti-submarine warfare, it takes a lot of time to fly at low altitude (70-600 m), and the majority of P-3C pilots have experienced spatial disorientation, so Upset prevention and recovery training is essential for naval P-3C pilots. To this end, this study intends to present measures for UPRT from limited conditions using the P-3C simulator owned by the Navy.