• 한국농공학회지
• /
• 제32권E호
• /
• pp.80-87
• /
• 1990

Energy balance equations Were developed to describe the heat transfer mechanisms in a double layer plastic greenhouse with a water curtain system. Heat transfer variables were determined by using various temperature data measured in a conventional prototype semicircular cross-section greenhouse over a range of water temperatures and water flow rates. The heat transfer coefficient between flowing water and greenhouse air was independent of water flow rates. But the heat transfer coefficient between water surface and the stagnant air space within the double plastic layer was dependent on water flow rates. Substituting the heat transfer coefficients, determined from the energy balance equations in the heat transfer equations, demonstrated various relationships among ambient air temperature, greenhouse air temperature, water temperature, and water flow rates. The heating benefits were linearly related to not only the inside and outside air temperatures but also to the water temperature. The energy conservation effects of the water curtain system were found even initial water temperatures were considerably lower than the greenhouse setting temperatures. Sensitivity analysis for heat transfer coefficients demonstrated that the heat transfer coefficient between greenhouse air and the stagnant air within the plastic layers was the most significant coefficient in the estimation of heating effects.

• 한국환경과학회지
• /
• 제22권4호
• /
• pp.425-433
• /
• 2013

A mass balance of process was calculated by using the analysis of basic unit and environmental assessment of all the processes of Busan fashion color industry cooperative that operates a combined heat and power plant and a bio treatment plant. The mass balance for the combined heat and power plant was done, based on boiler and water treatment processes while each unit reactor was used for the bio treatment plant. From the results above, a resource recycle network, a treatment flowchart for food waste water/wastewater treatment and a carbon reduction program were established.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2006년도 추계학술대회
• /
• pp.113-117
• /
• 2006

This paper Is for development of cooling module in order to maintain heat and water balance in fuel cell vehicle. Thermal management system for fuel cell is disadvantage because the temperature of coolant is lower than that of ICE and heat duty of radiator is higher. By CFD simulation, cool ing module was developed for water balance of system. Hot chamber test and hot area/high altitude test on cool ing module was completed.

• 신재생에너지
• /
• 제5권3호
• /
• pp.40-48
• /
• 2009

Recovered heat has been considered as a renewable energy in Europe since 2008 because its great effect on energy saving and carbon decreasing in plant process. Energy saving and decreasing green gas are critical issue today, so various technologies to save energy and decrease carbon dioxide in plant process have been applied to many industrial area. In this paper, the feasibility of condenser heat recovery by heat pump in power plant for district heating and fuel line preheating were reviewed by verifying energy (heat) balance and mass balance of power plant model. Some ways to compose proper system to recover heat of condenser are suggested and their possibilities are also reviewed. Limitations on heat recovery in power plant are also reviewed. The results are verified by calculating input/output energy based on actual performance test data of Taean Thermal Power Plant in Korea. There is noticeable improvement of plant performance in some cases which demand low temperature (<100 C) heat like distrcit heating, fuel line heating, and so forth.

• 한국자동차공학회논문집
• /
• 제5권5호
• /
• pp.51-66
• /
• 1997

A heat transfer model of the intake valve in a spark ignition engine is presented, which is calibrated with a number of the valve temperature profiles measured during engine warm-up for the gaseous fuel(propane). The valve is divided into four identical elements for which the assumption of lumped thermal mass is applied. The calibration is made so that the difference between the measued and simulated valve temperatures becomes minimal. Then the model is applied to the cases of the liquid fuel(indolene) to estimate the amount of the liquid fuel vaporized from the intake valve by assuming that fuel evaporation accounts for the deficit of the heat balance budget. The results of the model show quantitative contribution of each heat transfer source to the heat balance. The behavior of the calculated mass fraction of the fuel vaporized from the intake valve explains how the liquid fuel evaporate during engine warm-up. The mass fraction at warmed-up condition is closely related with the fraction directly targeted on the valve back by the fuel spray geometry.

• 시멘트
• /
• 통권29호
• /
• pp.45-52
• /
• 1969

• 시멘트
• /
• 통권18호
• /
• pp.61-77
• /
• 1966

• 한국가금학회지
• /
• 제20권3호
• /
• pp.151-159
• /
• 1993

본 연구는 항콕시듐 제제로 광범위하게 쓰이고 있는 nicarbazin이 닭의 고온 스트레스에 미치는 영향을 조사하고자 16수의 SCWL 수탉 성계를 사용하여 실시하였다. 옥수수-대두박 위주의 사료에 두 수준(0 및 125ppm)의 rucarbazin을 첨가하여, 두 처리의 환경온도(21 와 35~$36^{\circ}C$)하에서 4일간의 예비실험 기간을 거친 후, 2일 동안의 시료 및 자료 수집기간을 가졌다. 건물 섭취량과 건물 배설량은 고온 스트레스에 의하여 유의한 영향을 받지 않았으나, ricarbazin 첨가에 의하여 증가하였다. 그러나 건물 대사율은 nicarbazin첨가에 의하여 유의하게 감소하였다. 고온 스트레스는 또한 음수량과 증발에 의한 수분 손실을 증가시켰고, nicarbazin은 이러한 효과를 더욱 심화시켰다. 혈액 pH는 고온하에서 nicarbazin 첨가에 의해 증가되었으며, p$CO_2$는 고온하에서 nicarbazin에 의해 감소되었다. 고온 스트레스는 또한 체온을 상승시켰으며 nicarbazin 첨가는 이러한 효과를 심화시켰다. 이상의 결과를 종합하면, 닭이 고온 스트레스를 받으면 체온이 상승하게 된다. 따라서 닭은 체온 상승을 억제하기 위하여 호흡수를 증가시켜(panting) 수분 증발을 통한 체열 방출을 많게 한다. 그러나 nicarbazin 첨가는 고온하의 수탉 체온 상승 폭을 워낙 크게 하므로, panting에 의한 체열 방출량 증가만으로는 정상 체온을 유지하기가 어렵게 되는 것으로 풀이된다

• 운동영양학회지
• /
• 제13권1호
• /
• pp.75-81
• /
• 2009

This study aims to find out the effect of ingestion of 3 mg·kg^-1 caffeine on fluid-electrolyte balance and Tty change during exercise under heat environment of 30~32℃ (40-50% humidity). Five trained males who routinely trained for approximately 60 min·d^-1, 3-6 d·wk^-1 (age; 28.20±3.56yrs, height; 174.56±5.46 cm, body mass; 76.13±9.02 kg, body fat(%); 14.24±3.99, VO₂max; 54.00±4.30 mL·kg^-1·min^-1, exercise career; 4.20±1.95yrs) performed 40min of treadmill running in heat chamber. The study was a double-blind, randomized, crossover design. Body mass change following exercise was higher for the PLAC (Placebo) and CAFF (Caffeine) in comparison to the CON (Control), there was no significant difference between the CAFF, PLAC, CON (p= .997). The U_sg not significant differences (p= .731) and Osm_urine not significant differences between the CAFF, PLAC, CON (p= .901). There also were not significant between the CAFF, PLAC, CON for [Na⁺]_urine and [K⁺]_urine (p= .928, p= .469). In the case of Tty, although the increase rate of Tty was the highest for the CAFF on exercise early, exercise the second half in comparison to the CON and PLAC, there was not significant interaction effect between the CAFF, PLAC, and CON of Tty (p= .067), In conclusion, it was confirmed that the 3 mg·kg^-1 caffeine ingestion prior to exercising in heat environment does not impart negative effect on body fluid, electrolyte balance and changes in Tty.

• Asian-Australasian Journal of Animal Sciences
• /
• 제23권11호
• /
• pp.1462-1468
• /
• 2010

The effects of vitamin C and vitamin E with selenium on acid-base balance and some stress hormones were evaluated during heat stress in goats. Goats, 1.5 years of age, were divided into control, heat stress and antioxidant treatment groups 1, 2 and 3. Except for the control, all groups were exposed to a temperature of $40{\pm}2^{\circ}C$ with a relative humidity of 30% for 5 h/d for 21 days in a psychrometric chamber. Rectal temperature and respiratory rates were recorded daily post exposure. Blood samples were collected on every 3rd day for estimation of plasma vitamins C and E, total antioxidant activity and hormones, and separate blood samples were taken to estimate acid-base status. The rectal temperature and respiratory rates were increased (p<0.05) in the heat stress group only. Except for pH and $pO_2$, which were increased significantly (p<0.05) other parameters of acid-base balance such as $pCO_2$, $HCO_3^-$, $TCO_2$, BEb, BEcef, PCV and Hb were significantly decreased (p<0.05) in the heat stress group. An improvement in acid-base status was noted in the antioxidant supplemented groups. Prolactin and cortisol levels were significantly (p<0.05) higher and free T3 and T4 levels were significantly (p<0.05) lower in the heat stress group. Levels of prolactin and cortisol were decreased and free T3 and T4 were increased in antioxidant treatment groups. Different levels of antioxidant supplementation resulted in similar protection against heat stress.