• Asian-Australasian Journal of Animal Sciences
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• v.7 no.1
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• pp.97-101
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• 1994

Two experiments were conducted to study the effect of ambient temperature and nicarbazin on SCWL adult roosters. In Experiment 1, the effects of nicarbazin supplementation (125 ppm) on the water metabolism, blood acid-base balance; and rectal temperature of 16 birds in normal ($21^{\circ}C$) and hot ($35-36^{\circ}C$) temperature were investigated. In Experiment 2, the evaporative water loss and $CO_2$ exhalation from 8 birds were measured individually with an open-circuit gravimetric respiration apparatus in normal ($21^{\circ}C$) and hot ($33.5-34^{\circ}C$) temperature. The amount of water intake and evaporative water loss increased in birds under heat stress (HS). Nicarbazin exacerbated these effect in hot temperature. Also, nicarbazin decreased the blood $pCO_2$ and increased pH of HS birds. The rectal temperature of birds increased in hot temperature, and nicarbazin worsened this effect. The evaporative water loss, measured directly with respiration apparatus (Experiment 2), was increased in hot temperature. HS decreased the amount of $CO_2$ exhalation. Nicarbazin did not exert ant effect on either of these measurements, probably due to the limited duration (2 h) of the trial. The decrease in $CO_2$ exhalation by HS birds could be explained by reduced metabolic rate, which helps homeothermy of birds in hot temperature.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.87.2-87.2
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• 2010

The steady and dynamic process model for an internal reforming molten carbonate fuel cell power plant is discussed in this paper. The dominant thermal and chemical dynamic processes are modeled for the stack module and balance-of-plant, including cathode gas preparation, heat recovery, heat loss (Each heat loss amount for the stack and MBOP is obtained from real plant data) and fuel processing. Based on dynamic model and control demand, PID controllers are designed in the whole system. By applying these controllers we can obtain temperature balance of stack and control system depending on changing steam to carbon ratio, air feed amount, and transient condition.

• Journal of Mechanical Science and Technology
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• v.15 no.7
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• pp.921-930
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• 2001

A new theoretical critical heat flux (CHF) model was developed for the forced convective flow boiling at high pressure, high mass velocity, and low quality. The present model for an intermittent vapor blanket was basically derived from the sublayer dryout theory without including any empirical constant. The vapor blanket velocity was estimated by an axial force balance, and the thickness of vapor blanket was determined by a radial force balance for the Marangoni force and lift force. Based on the comparison of the predicted CHF with the experimental data taken from previous studies, the present CHF model showed satisfactory results with reasonable accuracy.

• Journal of the Korean Society of Combustion
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• v.21 no.1
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• pp.18-30
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• 2016

Pyro-process of solids is the way to heat solid materials under high temperature. In this processing, energy efficient use is one of the main concerns due to its high energy consumption of bulk materials. To calculate the energy use of processes, heat & mass balance in simplified 0-dimensional model was performed. Energy calculation by this simplified model can lead to confusion due to simplification. Thus, it is necessary to understand considerations of energy analysis. In this study, cement manufacturing as a very common example of pyro-processing of solids, was introduced for explaining considerations of energy analysis for energy efficient use.

• Nuclear Engineering and Technology
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• v.34 no.1
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• pp.68-79
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• 2002

The approach for evaluating the critical heat flux (CHF) margin using the departure from nucleate boiling ratio (DNBR) concept has been widely applied to PWR core design, while DNBR in this approach does not indicate appropriately the CHF margin in terms of the attainable power margin-to-CHF against a reactor core condition. The CHF power margin must be calculated by increasing power until the minimum DNBR reaches a DNBR limit. The Critical Power Ratio (CPR), defined as the ratio of the predicted CHF power to the operating power, is considered more reasonable for indicating the CHF margin and can be calculated by a CPR orrelation based on the heat balance of a test bundle. This approach yields directly the CHF power margin, but the calculated CPR must be corrected to compensate for many local effects of the actual core, which are not considered in the CHF test and analysis. In this paper, correction of the calculated CPR is made so that it may become equal to the DNB overpower margin. Exemplary calculations showed that the correction tends to be increased as power distribution is more distorted, but are not unduly large.

• Journal of Environmental Health Sciences
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• v.42 no.2
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• pp.92-101
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• 2016

Objectives: Outdoor workers are exposed to thermally stressful work environments. In this study, heat stress indices for harbor workers in summer were calculated to evaluate thermal comfort based on a human heat balance model. These indices are Physiological Subjective Temperature (PST), Dehydration Risk (DhR), and Overheating Risk (OhR) according to respective stage of cargo work in a harbor. In addition, we constructed a forecast system to provide heat stress information. Methods: Thermophysiological indices in this study were calculated using the MENEX model (i.e. the human heat balance model), which used as inputs the meteorological parameters, clothing insulation, and metabolic rate for each stage of cargo work in the harbor of Masan over the course of seven days, including a four-day heat wave. The forecast heat stress information constructed for Masan harbor was based on meteorological data supported by the Dong-Nae Forecast from the KMA (Korea Metrological Administration) and other input parameters. Results: According to higher metabolic rate, thermophysiological indices showed a critical level. In particular, PST was evaluated as reaching the 'Very hot' or 'Hot' level during all seven days, despite the heat occurring over only four. It is important in a regard to consider the work environment conditions (i.e. labor intensity and clothing in harbor). On a webpage, the forecast thermophysiological indices show as infographics to be easily understand. This webpage is comprised of indices for both current conditions and the forecast, with brief guidance. Conclusion: Thermophysiological indices show the risk level to health during a heat wave period. Heat stress information could help to protect the health of harbor workers. Further, this study could extend the applicability of these indices to a variety of outdoor workers in consideration of work environments.

• Journal of the Korean Society for Heat Treatment
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• v.8 no.3
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• pp.229-235
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• 1995

We were studied to the effect of alloying element and retained austenite on a mechnical properties and that used steels were composed three types composition. According to the soaking temperature, a retained austenite was pricipitated in the bainitic ferrite matrix and it was pricipitated to a flake type of about $2{\mu}m$, a mixture of massive and bar type and a flake type of about $1{\mu}m$ size. Through x-ray diffraction analysis, the amount of retained austenite was increased with addition of Si and Ni for equal heat treatment condition and it was best abundanted in the soaking temperature of $855^{\circ}C$. The balance value of strength and elongation were complexly controlled not only a retained austenite formation but also a formation characteristic and shape of the retained austenite and bainite. The balance value of strength and elongation were most satisfactory obtained with "B" and "C" specimens in a firstly heat treated at $855^{\circ}C$ and the best result was that a $2840kg/mm^2.%$ with the heat teratment condition of $855^{\circ}C-400^{\circ}C$ used for "C" specimen.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2001.05a
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• pp.45-52
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• 2001

The study on the heat exchanger with catalytic combustion was performed as the development of the catalytic combustion applications. This study tried to achieve the both goals-the mixture preheating and the heat transfer to working fluid simultaneously by using the steady state catalytic combustion. The combustion characteristics were investigated with the quantitative, qualitative experimental variants of the mixture. In addition, the temperature distribution of catalytic layer was investigated to investigate the correlation between the combustion characteristics and the heat balance of the catalytic layer. As a result, the steady state reaction within the appropriate range of temperature is the critical factor in catalytic applications. To get this, the sensible control of both the mixture flow and the heat balance of catalytic layer were required.

• Journal of applied mathematics & informatics
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• v.9 no.2
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• pp.731-744
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• 2002

The temperature distribution in human skin and subdermal tissue layer is presented using bioheat transfer equation. The body temperature is determined by the balance between heat produced and heat lost by our body. The time-dependent solutions have been found to be affected by the metabolic heat generation rate, blood mass flow, the rate of evaporation of perspiration and also by the atmospheric temperature. The analytic solutions for different layers have been calculated numerically and are also shown graphically.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.2 no.1
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• pp.11-26
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• 1990

The first kind LiBr -$H_2O$ absorption heat pump system was simulated and the performances of it were predicted. The elements of heat pump system, evaporator, absorber and generator were analysed by solving the energy balance equations and concentration equations which describe the reactions between working fluids. The results show that the temperature gain of absorber and condenser and the COP of the system are affected considerably by the operating conditions of heat pump system.