• 청정기술
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• 제5권2호
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• pp.53-61
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• 1999

대형 산업용 환경폐기물 처리 및 열병합 플랜트의 연소 및 소각 공정 후 발생하는 배기가스의 폐열회수장치 설계 방법을 제시하였다. 본 연구는 폐열회수장치의 기본 설계 개념을 폐열회수를 위한 보일러와 폐열을 이용한 증기 동력 사이클로 구성되는 것으로 가정하였고, 폐열회수장치에 필요한 각 구성요소들에 대한 모델링 기법과 그에 따른 설계 기준 및 설계 개념을 기술하였다. 또한 본 설계방법을 이용하여, 동일한 배기가스 조건에 대해, 폐열회수 보일러의 작동 압력 및 폐열회수 열교환기 설계에 따라 폐열회수장치의 열성능이 어떻게 변화되는지를 검토하였다.

• 수산해양기술연구
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• 제53권3호
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• pp.302-307
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• 2017

An electric steam boiler equipped with a condensate recovery system, which stores the condensate generated after using steam in steam washers, steam cookers, steam irons, and steam cleaners in a condensate tank and supplies compressed air to the condensate tank so that the condensate is recovered to the boiler by the pressure of the compressed air, was studied. In the results of this study, the heat energy balance between the quantity of the heat generated by the non-metallic surface heating element and the quantity of the heat absorbed by the water was good in a range of ${\pm}5%$. In addition, the heat transfer rate increased in proportion to the electric power of the surface heating element heater, the waste heat energy was normally recovered by the recovery of the condensate of the steam boiler equipped with the high compression waste heat recovery system, and the recovery rate of the waste heat exhibited 23%.

• 한국막학회:학술대회논문집
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• 한국막학회 1996년도 추계 총회 및 학술발표회
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• pp.22-33
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• 1996

With the experience of the 1994 drought, and the shortage of water resources in Japan, it has been re-informed upon us ensure and maintain the stability of water resources. Accordingly, with each plant, a serious appraisal has begun looking at the re-use of waste water. Membrane technology is an important process for waste water recovery. Effluent kom waste water facilities changes the quality of water significantly. The conventional pre-treatment of RO is hard to supply good quality feed water to RO in the waste water recovery system. The microfiltration system as a pre-treatment of RO in the paper overcomes the fouling with the air backwash and is operated in direct flow mode at a low pressure producing a high flux. The paper will focus the waste water recovery using membrane technology and many examples will be given.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 B
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• pp.806-808
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• 1993

New soft recovery drive which can alleviate the loss due to reverse recovery of diode is proposed. By using this drive, the reverse current of the diode is minimized and stabilized because there is inner local feedback loop between the turn-on current of the power MOSFET and the reverse recovery current of the diode. The loss and EMI noise can be considerably reduced in this way. Brief operational principle and experimental results are included to verify the usefulness.

• Environmental Engineering Research
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• 제25권2호
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• pp.222-229
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• 2020

Membrane assisted condenser is an innovative membrane operation that exploits the hydrophobic nature of microporous membranes to promote water vapor condensation and recovery. It can be used for water and chemicals recovery from waste gaseous streams. In this work, the testing of membrane condenser for water and ammonia recovery from synthetic streams (i.e., a saturated air stream with ammonia) simulating the plume of cooling tower is illustrated. The modeling of the process was carried out for predicting the membrane-based process performance and for identifying the minimum operating conditions for effectively recovering liquid water. The experimental data were compared with the results achieved through the simulations showing good agreement and confirming the validity of the model. It was found that the recovery of water can be increased growing the temperature difference between the plume and the membrane module (DT), the relative humidity of the plume (RH^plume) and the feed flow rate on membrane area ratio. Moreover, the concentration of NH₃ in the recovered liquid water increased with the growing DT, at increasing NH₃ concentration in the fed gaseous stream and at growing relative humidity of the feed.

• 한국응용과학기술학회지
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• 제24권4호
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• pp.347-353
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• 2007

Fleshing scrap is a kind of wastes produced during leather making process and used in the test of manufacturing biodiesel. The early step of manufacturing biodiesel is fat recovery from fleshing scrap. Hence, we investigated the influence of the way of fat recovery on the fatty acid composition. We used three different recovery ways, that is chemical method by protein decomposition with acid/fat recovering, physical method by protein denaturalization with heat and vacuum/fat pressing, and biodiesel method by protein decomposition/fat recovering. The biological method yielded the best results in terms of appearance transparency. It was most effective to lower acid value. Also the recovered fat by biological method would be favorable methyl-ester reaction raw material for biodiesel because it contains more than 5% of oleic acid among unsaturated fatty acid.

• Journal of Electrical Engineering and Technology
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• 제13권4호
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• pp.1752-1758
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• 2018

In a low-voltage distribution system, the molded case circuit breaker (MCCB) is a widely used device to protect loads by interrupting over-current; however the hot gas generated from the arc discharge in the interrupting process depletes the dielectric recovery strength between electrodes and leads to re-ignition after current-zero. Even though the circuit breaker is ordinarily tripped and successfully interrupts the over-current, the re-ignition causes the over-current to flow to the load again, which carries over the failure interruption. Therefore, it is necessary to understand the dielectric recovery process and the dielectric recovery voltage of the MCCB. To determine these characteristics, a measuring system comprised of the experimental circuit and source is implemented to apply controllable recovery voltage and over-current. By changing the controllable recovery voltage, in this work, re-ignition is driven repeatedly to obtain the dielectric recovery voltage V-t curve, which is used to analyze the dielectric recovery strength of the MCCB. A measuring system and an evaluation technique for the dielectric recovery strength of the MCCB are described. By using this system and method, the measurement to find out the dielectric recovery characteristics after current-zero for ready-made products is done and it is confirmed that which internal structure of the MCCB affects the dielectric recovery characteristics.

• 대한조선학회 특별논문집
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• 대한조선학회 2005년도 특별논문집
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• pp.198-205
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• 2005

Reduction of labor hour for cleaning up of the used abrasives after blasting. is attempted by improving the efficiency of abrasive recovery process in the protective coating of ship's block, For this purpose, the theoretical background for pneumatic transport technology in the abrasive recovery system as well as experimental evaluation on the effect of design parameters such as flow pattern, saltation velocity and pressure drop on the efficiency of the abrasive recovery system are employed . By optimizing the operating parameters such as the length and diameter of the suction hose, specification of recovery device and recovery mouth, a new method which can dramatically increase the efficiency of abrasive recovery system, is proposed.

• Reproductive and Developmental Biology
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• 제35권1호
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• pp.61-65
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• 2011

The objective of this study was to examine the effect of various discontinuous Percoll washing conditions on motile sperm recovery rate and motion kinematics. Frozen semen samples from 3 bulls (0.5 ml plastic straws, 6% glycerol in egg yolk-Tris-glycerol extender) were thawed in $37^{\circ}C$ water bath for 1 min. After thawing, the mixed semen samples were randomly allocated to 12 treatment groups. Briefly, the spermatozoa were centrifuged for three different time lengths (10, 20, and 30 min) at two gravities ($300{\times}g$ and $700{\times}g$) through two concentrations of discontinuous Percoll density gradient of 1 ml 90%: 1 ml 45% Percoll and 2 ml 90%: 2 ml 45% Percoll to remove extender, debris, and dead spermatozoa. Motile sperm recovery rate and motion kinematics were evaluated by computer assisted sperm analyzer using Makler counting chamber. Sperm motility (%) and motile sperm recovery rate showed similar pattern in all treatment groups. However, sperm motility (%) and motile sperm recovery rate were highest at $700{\times}g$ for 30 min through a discontionous Percoll density gradient of 1 ml 90%: 1 ml 45% Percoll. There were no significant differences in motion kinematics after various Percoll washings. These results suggest that force of centrifugation, centrifugation time, and Percoll volume significantly affect motile sperm recovery rate.

• 한국응용과학기술학회지
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• 제37권6호
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• pp.1646-1658
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• 2020

이 연구의 목적은 운동 후 수중회복방법의 차이가 성장호르몬, 테스토스테론, 혈중젖산농도, 심부담도, 통증의 변화를 알아보는 것이다. 저항운동 경력 6개월 이상인 남자 7명을 대상으로 집중 웨이트 트레이닝과 서킷 웨이트트레이닝을 1RM의 60%강도로 실시한 다음 회복방법으로 수중걷기회복과 수중앉기 회복을 진행하였다. 성장호르몬은 모든 운동형태와 회복방법에서 운동 후, 회복 후, 안정 시 순으로 높게 나타났으며, 테스토스테론은 운동 후, 회복 후, 안정 시 순으로 높았다. 혈중젖산농도는 모든 운동형태와 회복방법에서 운동 후, 회복 후, 안정 시 순으로 높았으며 집중저항운동 후 동적회복이 정적회복보다 낮았다. 심부담도는 모든 운동형태와 회복방법에서 운동 후, 회복 후, 안정 시 순으로 높았다. 근통증은 모든 운동형태와 회복방법에서 운동직후, 회복 후, 24시간, 48시간, 72시간 순으로 감소하였다. 물속 환경에서도 동적회복이 정적회복보다 근피로 개선에 효과가 있는 것으로 사료된다.