• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.11
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• pp.1127-1133
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• 2012

A finned-tube-type evaporator module has been proposed for a 2 t/h-class water-tube-type industrial boiler with multiple burners. The geometry of the fins was changed at each module to equalize the evaporation. The modules were designed by considering the energy balance at each row rather than by following a conventional bulk design procedure. The designed module was built into a 2 t/h-class water-tube-type boiler, and its performance was tested. A numerical simulation was also conducted to evaluate the two- or three-dimensional effects of factors such as the inlet conditions. The numerical simulation also included the conjugate heat transfer problem to predict the fin tip temperature. The heat transfer coefficient with fins is lower than that obtained from the empirical correlation of a bare tube. The fin tip temperature from CFD is higher than that from the analytical solution.

• Korean Journal of Organic Agriculture
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• v.24 no.4
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• pp.869-879
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• 2016

The present study was conducted to evaluate the effects of dietary formulated feed additive on growth performance and carcass traits of Hanwoo steers. A formulated feed additive reported to reduce heat load in the rumen in our previous research was used (Cho et al., 2014). Total 32 herds of Hanwoo steers were assigned into two groups of control and treatment. Total mixed ration was provided as basal diet for cattle and 100 g of additive was supplemented on diet for treatment. Feeding trial was performed during 120 days before slaughter. For growth performance, 3 periods (0~90 days; 90~120 days; 0~120 days) were allotted and average daily gain, feed requirement and final body weight were determined. Loin meat between $12^{th}$ and $13^{th}$ rib was used for meat quality analysis after slaughtering. Only $1^{st}$ period showed significantly improved growth performance of treatment (P<0.05) and there were no significant difference in other periods. At $3^{rd}$ periods (overall), a trend of increased average daily gain was found at treatment (P=0.075). Carcass performance and quality did not show significant differences between treatment and control (P>0.05). In meat quality, treatment showed significant increment in all measured meat colors (P<0.05) and significantly less sharing force compared to the control (P<0.05). Although no significant difference in growth performance and carcass yield were found, remarkably improved economic status was detected in treatment group. In conclusion, it could be suggested that application of a formulated feed additive specialized in reduction of heat load in the rumen was able to increase economical balance through enhancing heat stress condition of ruminant and growth.

• Journal of Environmental Science International
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• v.4 no.2
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• pp.139-150
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• 1995

The Quantitative estimations of the stratification - destratification(SD) phenomena in Deukryang Bay, Korea have been carried out based on the data of wind speed, heat flux through the sea surface and tidal current amplitude. To find out the main factors causing SD, wv introduce the rate of energy balance of the surface heat flux, tidal and wind stirring proposed by Simpson and Hunter(1974). The calculated potential energy of three terms are compared, from which the energy of wind stirring effect was one order smaller than the heat flux and the tidal stirring. Using the results, we complement time integration of the potential energy with the several s values of 0.010~0.014 at interval 0.001 and with wind speeds of 1.5 and 2.0 times larger than observation values at land. It shows that the variation of SD phenomena in the bay mainly depended on tidal stirring and sea surface heating in summer if there is no exceptionally strong wind event like Typhoon. The stratification become to be foamed from about 5 July although the stratification a little decreases during the second spring tidal period of middle of July.

• Journal of Korean Medical classics
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• v.30 no.3
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• pp.95-108
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• 2017

Objectives : The concept of hidden Yin in summer by Zhu Danxi deals with the relationship between summer heat disease and hidden yin inside of human body. This paper attempts to ponder upon the clinical issues around which the discussions regarding the topic unfolded, and upon the texts on which the doctors of the discussions based their opinions. Methods : First, Danxi's argument as discussed in $G{\acute{e}}zh{\grave{i}}y{\acute{u}}l{\grave{u}}n$ is analyzed to find out his understandings of clinical issues and his textual sources on which he based his new perspective. Moreover, the prescriptions that Danxi thought was problematic and the concept of hidden yin as it existed before the time of Danxi are reviewed, and these findings are used understand Zhangjingyue's ground of criticism against Danxi. Lastly, this paper contemplates how these opposing opinions may be helpful to the general principles of medical theories. Results & Conclusions : There was a trend before the time of Danxi of abusing drugs as prescription based on warm-heat, understanding that a human body has yin-cold during summer. However, Danxi brought forth a new concept of yin deficiency in order to correct people's misunderstanding. Despite his effort, Zhangjingyue and other doctors contemporary to Danxi emphasized on one hand that human body is placed on a state of external heat inside the cold, and on the another, criticized Danxi of failing to fully understand the principle of "Abandon the time and follow the symptoms", a principle which asserts that the cold and warm of medicine should be decided by the symptom itself and not by the season. The value of these contradicting assertions seems to hold true even to this day because it helps us understand that the principles of "Counting Season as a Treatment Factor" and "Abandon the time and follow the symptoms" could be applied with balance in conjunction with each other.

• Proceedings of the KSRS Conference
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• v.1
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• pp.21-24
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• 2006

Processes controlling the interannual variation of mixed layer temperature (MLT) averaged over the NINO3 domain ($150-90^{\circ}W$, $5^{\circ}N-5^{\circ}S$) are studied using an ocean data assimilation product that covers the period of 1993 to 2003. Advective tendencies are estimated here as the temperature fluxes through the domain's boundaries, with the boundary temperature referenced to the domain-averaged temperature to remove the dependence on temperature scale. The overall balance is such that surface heat flux opposes the MLT change but horizontal advection and subsurface processes assist the change. The zonal advective tendency is caused primarily by large-scale advection of warm-pool water through the western boundary of the domain. The meridional advective tendency is contributed mostly by Ekman current advecting large-scale temperature anomalies though the southern boundary of the domain. Unlike many previous studies, we explicitly evaluate the subsurface processes that consist of vertical mixing and entrainment. In particular, a rigorous method to estimate entrainment allows an exact budget closure. The vertical mixing across the mixed layer (ML) base has a contribution in phase with the MLT change. The entrainment tendency due to temporal change in ML depth is negligible comparing to other subsurface processes. The entrainment tendency by vertical advection across the ML base is dominated by large-scale changes in wind-driven upwelling and temperature of upwelling water. Tropical instability waves (TIWs) result in smaller-scale vertical advection that warms the domain during La Ni? cooling events. When the advective tendencies are evaluated by spatially averaging the conventional local advective tendencies of temperature, the apparent effects of currents with spatial scales smaller than the domain (such as TIWs) become very important as they redistribute heat within the NINO3 domain. However, such internal redistribution of heat does not represent external processes that control the domain-averaged MLT.

• Journal of the Korean Geotechnical Society
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• v.29 no.8
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• pp.65-73
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• 2013

Ground-coupled heat pump system has attracted attention as a promising renewable energy technology due to its improving energy efficiency and eco-friendly mechanism for space cooling and heating. Pipes buried in the ground play a role of direct thermal interaction between circulating fluid inside the pipe and surrounding soils in the geothermal exchange system. However, both complexities of turbulent flow coupling thermal-hydraulic phenomena and very long aspect ratio of the pipe make it difficult to model the heat exchange system directly. Energy balance for fluid flow inside the pipe was derived to model thermal-hydraulic phenomena, and one-dimensional pipe element was proposed through Galerkin formation and time integration of the equation. Developed element is combined to pre-developed FEM code for THM phenomena in porous media. Numerical results of Thermal Response Test showed that line-source model overestimates equivalent thermal conductivity of surrounding soils due to thermal interaction between adjacent pipes and finite length of the pipe. Thus, inverse analysis for the TRT simulation was conducted to present optimal transformation matrix with utmost convergence.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.5
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• pp.655-658
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• 2004

Heat stress is known to affect physiological systems in goats. This study investigated changes in nutrient digestibility, behavior and growth hormone secretion among goats in a hot environment (H; 35${\pm}$ 1.2$^{\circ}C$, [RH] 80${\pm}$7.2%, 13 d), and in a thermoneutral environment (T; 20${\pm}$0.6$^{\circ}C$, [RH] 80${\pm}$3.4%, 20 d), and accompanied by the same restricted diet as provided in the hot environment. The following results were obtained: rectal temperature and water intake were higher in the H treatment than in the T treatment or TR treatment, while hay consumption was lower. CP, NDF and ADF digestibility was highest in H treatment. Time spent eating in the H treatment was also the highest, followed in order by T treatment and TR treatment. Ruminating time was lower in H treatment than in T treatment or TR treatment, and reposing time was highest in the TR treatment. Growth hormone concentrations in T increased 4.5 h after feeding. In H, growth hormone concentrations increased 0.5 h after feeding. However, growth hormone concentrations were not changed following TR feeding. In conclusion, heat exposure in goats decreased feed intake, but increased digestibility. However, when goats in a thermoneutral environment received the same restricted feeding as they received in the hot environment, digestibility increased. Between the H treatment and TR treatment, the changes in digestibility were accomplished by coordinate changes in hormone secretion in order to maintain body homeostasis. To maintain energy balance under a hot temperature or a restricted feeding condition, goats may control their metabolism by changing growth hormone release.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.6
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• pp.652-656
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• 1997

This study was conducted to determine the relationships between abdominal temperature (Tabd) and some thermoregulatory responses, such as heat production (HP), heart rate (HR), respiration rate (RR), temperature of external ear tract (Tee), comb surface temperature (Tcs) and shank skin temperature (Tss), for revealing the role of deep body temperature in the thermoregulation of broiler chickens. Tabd was divided into 5 zones of 40-41, 41-42, 42-43, 43-44 and $44-45^{\circ}C$, and maintained for 3 hours in each zone by varying environmental temperature from 11 to $33^{\circ}C$. HP and HR had a greater increase with Tabd above $42.5^{\circ}C$. RR increased markedly with Tabd above $41.5^{\circ}C$, and reached a maximum when Tabd was at $42.5^{\circ}C$, then began to decrease. In addition, HP and HR increased significantly with decrease RR during the decreasing phase of panting. Tcs and Tss changed rapidly with Tabd when Tabd was below $41.5^{\circ}C$, and increased more slowly above $41.5^{\circ}C$. Tee was lower than Tabd, and its increase was less than that of Tabd. These results suggest that changes in thermoregulatory responses are induced by an increase in abdominal temperature. Tabd increases to adjust the ratio of sensible and evaporative heat loss when Tabd is below $42.5^{\circ}C$, while the ability in body temperature regulation gradually disappears when abdominal temperature exceeds $42.5^{\circ}C$ and heat balance can not be maintained.

• 한국태양에너지학회:학술대회논문집
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• 2011.04a
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• pp.204-209
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• 2011

According to the environment report of UN, korea was classified as potable water shortage countries. Approximately 71% of the Earth's surface is covered by ocean. However, it is difficult to use for industry of residential purpose without a certain processing. The development of solar and waste-heat used absorption desalination technology have been examined as a viable option for supplying clean energy. In this study, the modelling of the main devices for solar and waste-heat used and adsorption desalination system was introduced. The design is divided into three parts. First, the evaporator for the vaporization of the top water is designed, and then the reactor for the adsorption and release of the steam is designed, followed by the condenser for the condensation of the fresh water is designed. In addition, new features based on the energy balance are also included to design absorption desalination system. In this basicresearch, One-bed(reactor) adsorption desalination plant that employ a low-temperature solar and waste energy was proposed and experimentally studied. The specific water yield is measured experimentally with respect to the time controlling parameters such as heat source temperatures, coolant temperatures, system switching and half-cycle operational times.

• Structural Engineering and Mechanics
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• v.25 no.4
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• pp.445-466
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• 2007

As the LNG (Liquefied Natural Gas) tank contains cryogenic liquid, realistic thermal analyses are of a primary importance for a successful design. The structural details of the LNG tank are so complicated that some strategies are necessary to reasonably predict its temperature distribution. The proposed heat transfer model can consider the beneficial effects of insulation layers and a suspended deck on temperature distribution of the outer concrete tank against cryogenic conditions simply by the boundary conditions of the outer tank model. To this aim, the equilibrium condition or heat balance in a steady state is utilized in a various way, and some aspects of heat transfer via conduction, convection and radiation are implemented as necessary. Overall thermal analysis procedures for the LNG tank are revisited to examine some unjustifiable assumptions of conventional analyses. Concrete and insulation properties under cryogenic condition and a reasonable conversion procedure of the temperature-induced nonlinear stress into the section forces are discussed. Numerical examples are presented to verify the proposed schemes in predicting the actual temperature and stress distributions of the tank as affected by the cryogenic LNG for the cases of normal operation and leakage from the inner steel tank. It is expected that the proposed schemes enable a designer to readily detect the effects of insulation layers and a suspended deck and, therefore, can be employed as a useful and consistent tool to evaluate the thermal effect in a design stage of an LNG tank as well as in a detailed analysis.