• 제목/요약/키워드: DHC

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OEMGD 알고리즘을 이용한 건물 냉난방용 최적 에너지 믹스 모델에 관한 연구 - 지열히트펌프와 지역냉난방 시스템을 중심으로 (A Study on the Optimal Energy Mix Model in Buildings with OEMGD Algorithm Focusing on Ground Source Heat Pump and District Heating & Cooling System)

  • 이기창;홍준희;이규건
    • 한국지역사회생활과학회지
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    • 제27권2호
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    • pp.281-294
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    • 2016
  • This study was conducted to promote consumer interest in Geothermal Heat Pump (Ground Source Heat Pump, GSHP) and district heating and cooling (District Heating & Cooling, DHC) systems, which are competing with each other in the heating and cooling field. Considering not only the required cost data of energy itself, but also external influence factors, the optimal mix ratio of these two energy systems was studied as follows. The quantitative data of the two energy systems was entered into a database and the non-quantitative factors of external influence were applied in the form of coefficients. Considering both of these factors, the optimal mix ratio of GSHP and DHC systems and minimum Life Cycle Cost (LCC) were obtained using an algorithm model design. The Optimal Energy Mix of GSHP & DHC (OEMGD) algorithm was developed using a software program (Octave 4.0). The numerical result was able to reflect the variety of external influence factors through the OEMGD algorithm. The OEMGD model found that the DHC system is more economical than the GSHP system and was able to represent the optimal energy mix ratio and LCC of mixed energy systems according to changes in the external influences. The OEMGD algorithm could be of help to improve the consumers' experience and rationalize their energy usage.

자외선에 의한 비타민 $D_3$합성과 직물(제1보) -실험관내 실험 - (UVB Photosynthesis of Vit. D3 and Fabrics (Part I) -in vitro-)

  • 안령미;송명견
    • 한국의류학회지
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    • 제21권5호
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    • pp.903-910
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    • 1997
  • Vit. D3 was measured which was produced by UVB irradiation to provit. D3, 7-d ehyd rock o 1 cst or of (7-DH Cl Measuring the amount of vie. D3 when it was irradiated to the fabrics which had different UV8 transmittance, production of vile. Ds by UVB(Ultraviolet B) and inhibition from formation of vile. D3 by fabrics were absorbed and followings are the results. As the amount of irradiated compared UVB increased, the amount of the production of vile. D3 produced by UVB irradiation from 7-DHC was increased. After treatment of 7-DHC by UVB irradiation and incubated respectively for 24hr, 48hr and 72hr at 36.5$^{\circ}C$ The amount of lit. D3 was increased as incubating time passed. When irradiated UVB on 7-DHC, intermediate of vile. D3, lumisterol, tachysterol and previt. D were showed and those materials were seemed to be changed to vile. D3 as incubation time passed. The amount of vile. D3 which was produced by irradiation 7-DHC showed close relation with UVB transmittance rate of summer fabrics (r= 0.987). Clothes, hats, and sun screen cream reduce the amount of vile. D3 Produced naturally in human skin and it result the decrease of calcium in blood which is absorbed through vit. D. Those all can cause or worsen osteomalacia especially to women and the aged people. Therefore, it is necessary to research and to develop function oriented clothing which can transmit UV which produce vile. D3 at the same time which can protect toxical UVB.

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치과에 내원한 젊은 성인의 교정치료의 필요성과 자기 인식간의 관계 (Associations between normative and self-perceived orthodontic treatment needs in young-adult dental patients)

  • Oshagh, Morteza;Salehi, Parisa;Pakshir, Hamidreza;Bazyar, Leyla;Rakhshan, Vahid
    • 대한치과교정학회지
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    • 제41권6호
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    • pp.440-446
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    • 2011
  • Objective: Our aim was to determine the correlation between dental treatment need as assessed by the components of the index of orthodontic treatment need (IOTN) and a self-evaluation questionnaire in a population selected from the dental clinics of Shiraz, Iran. Methods: The dental treatment needs of 240 participants (120 men and 120 women) were measured on the basis of the IOTN dental health component (IOTN-DHC), IOTN aesthetic component (IOTN-AC), IOTN AC determined by the examiner (IOTN-ACE), and a self-evaluation questionnaire (SEQ). The correlations between the treatment needs assessed by all the methods as well as the correlations of the treatment needs with age and gender were assessed using a Spearman's correlation coefficient (${\alpha}$ = 0.01). Results: All methods were significantly correlated ($p{\leq}0.001$). The associations of IOTN-ACE with IOTN-DHC and SEQ were moderately significant (rho = 0.49 and 0.41, respectively). The associations of IOTN-AC with IOTN-DHC and SEQ were weakly significant (rho = 0.24 and 0.35, respectively). The IOTN-DHC was moderately associated with SEQ (rho = 0.53). Gender and age were not associated with treatment needs estimated by any of the methods used ($p$ > 0.06). Conclusions: The correlations between the self-evaluation and the IOTN components in young adults were close to those reported in children, and IOTN-ACE was more reliable than IOTN-AC.

Zr-2.5Nb 중수로 압력관의 수소지연파괴에 미치는 압력관 두께의 영향 (Effect of an Increased Wall Thickness on Delayed Hydride Cracking in Zr-2.5Nb Pressure Tube)

  • Jeong, Yong-Hwan;Kim, Young-Suk
    • Nuclear Engineering and Technology
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    • 제27권2호
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    • pp.226-233
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    • 1995
  • CANDU 원자로에서 심각하게 대두되는 압력관 파손을 방지하기 위해 압력관의 두께를 증가시키는 방안이 연구되었다. 본 연구에서는 압력관 두께변화가 Zr-2.5Nb 압력관의 응력, 수소농도 및 수소지연파괴에 미치는 영향에 대해 연구를 수행하였다. 압력관 두께가 현재의 4.2 mm에서 5.2 mm로 증가할 경우에 압력관이 받는 응력과 발전소 가동중에 누적되는 중수소 흡수량은 19% 줄어드는 것으로 나타났으며, 압력관에 균열이 발생할 경우 발전소 냉각동안에 일어나는 균열 성장은 상당히 감소한다. 수소지연파괴는 압력관이 받는 응력과 누적되는 수소량에 비해 지배되는데 이와 같은 결과로부터 두꺼운 압력관은 수소지연파괴 관점에서 상당한 이점이 있는 것으로 평가되었다. 그러나 압력관 두께 증가는 수소지연파괴의 성장속도를 가속할수도 있으므로 앞으로 연구할 사항이다.

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대두와 된장분말이 고콜레스테롤식이를 급여한 흰쥐의 콜레스테롤 농도 및 항산화 활성에 미치는 영향 (Effects of Powders of Soybean and Doenjang on Cholesterol Level and Antioxidant Activities in Rats Fed with a High Cholesterol Diet)

  • 이재준;김아라;이환;김철호;장해춘;이명렬
    • 생명과학회지
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    • 제20권7호
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    • pp.1134-1142
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    • 2010
  • 본 연구는 고콜레스테롤식이를 급여한 흰쥐에게 동일 품종의 국산 원료 대두로부터 제조된 감압 증자한 대두분말 혹은 B. subtilis DJI 균주로 접종 후 천일염을 첨가하여 제조한 된장분말을 함께 급여하였을 경우 혈청 중 콜레스테롤 저하효과와 간 조직 중 항산화효과에 미치는 영향을 알아보고자 실시하였다. 실험군은 정상군(N), 고콜레스테롤군(HC), 고콜레스테롤과 대두분말식이군(SHC) 및 고콜레스테롤과 DJI 된장분말식이군(DHC)으로 나누어 4주간 실시하였다. 체중증가량과 식이섭취량은 SHC군과 DHC군이 HC군과 N군에 비하여 유의하게 감소되었다(p<0.05). 식이효율은 실험군 간에 유의적인 차이가 없었다. 혈청 중 AST, ALT 및 ALP활성은 고콜레스테롤과 대두 혹은 된장분말을 함께 급여한 SHC군과 DHC군이 고콜레스테롤 만을 급여한 HC군에 비하여 저하되었으며(p<0.05), N군과는 비슷한 활성을 나타내었다. 혈청 중 중성지질, 총콜레스테롤 및 LDL-콜레스테롤 함량은 HC군에 비하여 SHC군과 DHC군에서 유의적으로 감소되는 경향이었고(p<0.05), HDL-콜레스테롤 함량은 증가하는 경향을 보였다. 대두 혹은 된장분말을 함께 급여하였을 경우 고콜레스테롤식이로 증가된 간 조직 중 유리기해독계 효소인 catalase 및 GSH-Px 활성 억제와 항산화작용을 나타내는 GSH 함량을 증가시킴으로서 지질과산화물에 대한 방어력이 증가되었다. 콜레스테롤 저하 및 항산화효과는 대두분말과 된장분말 간에 차이가 거의 없었다. 이상의 결과 대두 혹은 된장분말은 고콜레스테롤식이로 유도된 산화적 손상에 대한 간 보호효과와 혈청 중 콜레스테롤 저하효과가 있는 것을 알 수 있었다.

결함발생 시점을 고려한 CANDU 압력관 결함의 확률론적 건전성평가 (Probabilistic Integrity Assessment of CANDU Pressure Tube for the Consideration of Flaw Generation Time)

  • 곽상록;이준성;김영진;박윤원
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 추계학술대회논문집A
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    • pp.155-160
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    • 2001
  • This paper describes a probabilistic fracture mechanics (PFM) analysis based on Monte Carlo (MC) simulation. In the analysis of CANDU pressure tube, it is necessary to perform the PFM analyses based on statistical consideration of flaw generation time. A depth and an aspect ratio of initial semi-elliptical surface crack, a fracture toughness value, delayed hydride cracking (DHC) velocity, and flaw generation time are assumed to be probabilistic variables. In all the analyses, degradation of fracture toughness due to neutron irradiation is considered. Also, the failure criteria considered are plastic collapse, unstable fracture and crack penetration. For the crack growth by DHC, the failure probability was evaluated in due consideration of flaw generation time.

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지르코늄합금의 DHC 현상

  • Kim, Young-Suk;Ahn, Sang-Bok;Kim, Sung-Soo
    • 한국원자력학회:학술대회논문집
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    • 한국원자력학회 2004년도 추계학술발표회 발표논문집
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    • pp.937-938
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    • 2004
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