• 한국가금학회지
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• 제46권4호
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• pp.223-234
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• 2019

This study investigated the effects of thawing methods and storage time on the quality of frozen duck meat. Meat was obtained from eight-week-old Korean native ducks (average weight=2.8 kg). Seventy-two samples were divided into eight treatments (three replicates/treatment, three samples/replicate) with 2 × 4 factorial arrangement based on two thawing methods (under running water at 12℃ for 3 h and in a refrigerator at 5℃ for 24 h) and four storage times (1, 3, 6, and 12 months). CIE b^* was significantly different among different storage time treatments, reaching its lowest after 6 months (P<0.05). Cooking loss did not differ between storage times; however, it was significantly lower following application of the fast thawing treatment (P<0.05). Water-holding capacity of meat stored for one month was highest compared to that of meat stored for a longer period (P<0.05). Additionally, there were significant differences based on storage time in γ-linoleic acid (C18:3n6) and eicosenoic acid (C20:1n9) contents (P<0.01), as well as in protein contents (P<0.05). Palmitoleic acid (C16:1n7) typically decreased after three months of storage; however, this decline was not significant compared to other storage times. Essential amino acids contents, except methionine, were significantly difference at six and 12 months of storage (P<0.05). Similarly, non-essential amino acid contents, except tyrosine, were significantly different among storage periods (P<0.05, P<0.01). Alternatively, there were no significant differences in the chemical composition, fatty acid content, or amino acid content based on the thawing method.

• 태양에너지
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• 제11권2호
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• pp.41-50
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• 1991

본 연구는 상변화물질로써 용융점온도가 $62^{\circ}C$인 파라핀($C_{28}H_{58}$)과 용융점온도가 $79^{\circ}C$인 피로인산나트륨($Na_4P_2O_7{\cdot}10H_2O$)을 사용하여 축열 및 방열과정 시 잠열축열조내에서 각 상변화물질의 시간경과에 따른 온도특성 및 열전달현상을 실험적으로 규명한 것으로 각 상변화물질의 온도분포와 축열량 및 방열량을 계산하고 이를 비교, 검토한 것이다. 파라핀의 경우 축열과정초기에 자연대류 열전달현상으로 인하여 온도가 서서히 증가하는 반면 피로인산나트륨의 경우는 전도 열전달 현상의 지배적인 영향으로 인하여 축열과정 초기에 온도가 급격히 증가하는 형태로 나타났다. 또한 축열 및 방열과정 시 파라핀의 경우 tube의 상하부벽면에서의 온도변화와 중심부의 온도변화가 큰 차이를 보였으나 피로인산나트륨의 경우 tube의 상하부 벽면에서의 온도와 중심부에서의 온도는 큰 차이를 나타내지 않았다. 그리고 축열과정 시 동일질량에 대한 각 상변화물질의 축열량은 파라핀보다 피로인산나트륨이 약 16%정도 많은 것으로 나타났다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집D
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• pp.260-265
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• 2001

This paper describes total flow control of an ice slurry system for pump energy saving. Similar turbo machinery has a characteristic that input power ratio is proportional to the three time of revolution speed ratio. To reduce the energy cost of brine pump in ice slurry storage systems, inverter is adapted instead of 3-way valve to control the speed of brine pump motor. One type of cooling load profile was used as driving load of the system, generated by a boiler and warm water storage tank. As results of the laboratory test, energy consumption and cost of the pump were reduced by 11.4%.

• 에너지공학
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• 제9권4호
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• pp.366-371
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• 2000

본 연구는 동적형 빙축열시스템에 있어서 증발판이 축열조 상부에 설치되어 생성된 얼음을 주기적으로 분리, 이탈시켜 하부에 설치된 축열조에 저장하는 기존의 하베스트형 빙축열시스템과는 반대로 축열조 내에 증발판을 설치하여 수중에서 얼음을 생성시키고 분리시켜 부럭에 의해 얼음을 띄워 저장하는 새로운 방식의 수중 하베스트형 빙축열시스템 개발에 관한 연구이다. 본 방식은 축열조 내에 증발판이 설치되어 제빙과 탈빙이 이루어짐으로서 기존 시스템에 설치되는 순환펌프나 순환수 분배기 및 배관 등의 설비가 불필요하고, 또한 조내 물과 증발판이 직접접촉에 의해 열교환이 이루어지므로 기존 공기 중에서의 열교환 방식보다 전열효율이 우수한 장점을 가지고 있다. 따라서 본 연구에서는 상기의 수중 빙제조 방식에있어 빙 제조시와 방냉시 축열조의 열특성을 실험적으로 밝혀 시스템 최적화 및 성능 향상에 대한 기초 자료를 제공하고자 하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(2)
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• pp.592-596
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• 2004

This paper deals with the operation of a flywheel energy storage UPS. The ups has good features such as long life-time, improved efficiency, no environment problems, reduced size and space, and low maintenance cost compared with the conventional UPS using battery. The operating principle of the UPS is analysed in each mode including charging, voltage compensation, discharging, and voltage unbalance compensation. Especially, the tracking characteristic of the disturbed phase of the source voltage after outage is analysed. The usefulness of the operation is proved through simulations.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.149-151
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• 2005

A new approach considering CO2 air pollution constraints in the long-term generation mix is proposed under uncertain circumstances. A characteristic feature of the presented approach in this paper is what effects give the air pollution constraints in long term best generation mix. Best generation mix problem is formulated by linear programming with fuel and construction cost minimization with load growth, reliability (reserve margin rate) and air pollutionconstraints. The proposed method accommodates the operation of pumped-storage generator. It was assumed in this study that the construction planning of the hydro power plants is given separately from the other generation plans. The effectiveness of the proposed approach is demonstrated by applying to the best generation mix problem of KEPCO-system, which contains nuclear, coal, LNG, oil and pumped-storage hydro plant multi-years.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2012년도 추계학술대회 논문집
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• pp.61-62
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• 2012

본 논문에서는 10kW급 리튬계열 에너지 저장장치 (ESS;Energy storage system)의 전기화학적 온도특성을 분석하였다. 70개 $LiFePO_4$ 단위 셀의 직렬결합(70S1P)으로 이루어진 ESS의 온도특성 분석을 위해 여름(7월)과 겨울(1월)일때의 ESS Tray/Rack/Cell 전압(표준편차) 및 온도데이터(최대값/최소값)의 통계처리를 실시하였다. 실험결과를 통해, 주변 외기온도에 영향을 최소화한 안정적인 ESS의 최적구축을 위한 가이드 라인을 제시할 수 있다.

• 전력전자학회논문지
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• 제17권6호
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• pp.539-545
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• 2012

Due to merits cost and efficiency, the transformer-less type photovoltaic (PV) inverters have been popularized in the solar market. However, the leakage current flowing through a parasitic capacitor between PV array and ground can cause adverse effect in the transformer-less PV system. In this paper, a bi-directional PV inverter with high efficiency and low noise is proposed for the PV system with an energy storage device. The proposed inverter is a transformer-less type and performs the bi-directional power control between dc sources and grid with high efficiency. In addition, the proposed inverter can suppress the leakage current and obtain low noise characteristic. Finally, 3-kW prototype was implemented to confirm validity of the proposed inverter.

• 한국조리학회지
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• 제14권4호
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• pp.55-66
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• 2008

This study investigated the rheological and sensory characteristics of pickle with frozen pine mushroom. P3(Developed pickle seasoning) was the best by preference among three kinds of pine mushroom pickle seasoning. For flavor and functionality, pine mushroom pickle was processed by using three kinds of method(P3-1: P3+cinnamon 10 g, P3-2: P3+licorice 10 g and P3-3: P3+licorice 5 g+cinnamon 5 g). As a result, the product from P3-3(P3+licorice 5 g+cinnamon 5 g) was the best preferred pine mushroom pickle. The pH value of P3-3 was 2.15, 42.9 degrees Brix, and its color value was L(54.65), a(-1.61), b(17.87). Its texture level was higher than that of other products, but it would be lowered on storage. Until the 28th day of storage, microorganisms in pine mushroom pickle seasoning were detected less than 30 CFU/mL.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.66.1-66
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• 2002

Today it becomes a serious problem to exhaustion of a fossil fuel and air pollution by exhaust gases from road vehicles for environment preservation. To solve this problem, the developments of a hybrid vehicle have been processed for the purpose of reducing pollution and energy-savings. By the way, flywheel hybrid vehicle using variable pump/motor was proposed as one feasible hybrid system in place of hybrid vehicle system by the conventional storage battery. The proposed flywheel hybrid vehicle is composed of an accumulator or a flywheel as the energy generation and storage source and three variable hydraulic pump/motor as the energy transfer device. Flywheel has the characteristic of high...