• Asian-Australasian Journal of Animal Sciences
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• v.23 no.3
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• pp.355-365
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• 2010

The aim of this study was to investigate the effect of supplemental recombinant bovine somatotropin (rbST) and cooling with misters and fans on renal function in relation to regulation of body fluids in different stages of lactation in crossbred Holstein cattle. Ten, 87.5% crossbred Holstein cattle were divided into two groups of 5 animals each, housing in a normal shaded barn (NS) and in a shaded barn with a mister-fans cooling system (MF). The experiment in each group was divided into 3 phases, early- (Day 75 postpartum), mid- (Day 135 postpartum), and late stage of lactation (Day 195 postpartum). The pre-treatment study was conducted on the starting day of each stage of lactation and the treatment study was performed after the end of the pre-treatment, during which the animal was injected with 500 mg of rbST (POSILAC) every 14 days for three times. During the study, ambient temperature at the hottest period daily in the MF barn was significantly lower, while relative humidity was higher than that of the NS barn. The temperature humidity index (THI) in both barns ranged from 79-85 throughout the periods of study. Cows in the MF barn showed a lower rectal temperature and respiration rate as compared with cows in the NS barn. The effect of rbST administration increased both rectal temperature and respiration rates of cows housed in either the NS or MF barn. Milk yield significantly increased in cows treated with rbST in all stages of lactation. Increases in mammary blood flow, accompanied by increases of total body water (TBW), extracellular fluid (ECF), blood volume (BV) and plasma volume (PV), were observed in both groups of cows receiving rbST in all stages of lactation. No alterations of renal blood flow and glomerular filtration rate were observed in cows receiving rbST, but decreases in urinary excretion and fractional excretion of sodium, potassium and chloride ions appeared to correlate with reduction in the rate of urine flow and osmolar clearance during rbST administration. These results suggest that the effect of rbST supplementation to cows housed either in NS or MF barns on body fluid volume expansion is attributable to changes in the rate of electrolyte excretion by the kidney. The increased availability of renal tubular reabsorption of sodium, potassium and chloride ions during rbST treatment was a major factor in retaining body water through its colligative properties in exerting formation of an osmotic force mechanism.

• Entomological Research
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• v.48 no.6
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• pp.550-558
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• 2018

To develop a system for the mass production of Protaetia brevitarsislarvae (Pbl), this study analyzed the oviposition characteristics of third instar Pbl through successive rearing and cold treatments. In the first generation, females laid 50 eggs each on average, and spawned higher numbers of eggs for the first 5 days but then fewer after this. However, all of the $2^{nd}$-generation females that were produced through the successive rearing of eggs from the $1^{st}$ generation did not spawn. When test insects (TI) were raised at $32^{\circ}C$, their $mean{\pm}SE$ pupal period and emergence rate were $28.4{\pm}1.9$ days and 87%, respectively. However, most individuals raised in cold treatments ($5^{\circ}C$ and $-5^{\circ}C$) without a pre-cooling period did not survive. Individuals exposed to a pre-cooling period, however, had a 7-10 days longer pupal period than those raised at $32^{\circ}C$, and their emergence rate (90%) was slightly higher. Different cold treatment temperatures ($0^{\circ}C$, $3^{\circ}C$, or $5^{\circ}C$) and periods (30 or 60 days) were tested in further experiments. The experimental group kept for 30 days at $0^{\circ}C$ and $3^{\circ}C$ had the shortest pupal period of all, and emergence rates exceeded 90% in most groups. With respect to the number of eggs spawned by the second generation females after cold treatments, the experimental groups held in cold treatments at $5^{\circ}C$ for 30 and 60 days were found to spawn the most eggs. Consequently, the experimental group kept at $5^{\circ}C$ for 30 days was the most effective set of conditions tested during the entire breeding period.

• Journal of Dairy Science and Biotechnology
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• v.24 no.1
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• pp.1-7
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• 2006

This experiment was performed to identify the improvement of raw milk quality after introducing raw milk grading system(1993, June). The purpose of this experiment was to investigate chemical component and microbiological quality of raw milk in jeju. This experiment made it possible to spread high standard of quality of raw milk or milk product including yoghurt, ice cream etc., and to provide dairy industry information for the construction of Jeju international free city master plan. As a result, automatic milking system is improved a lot after introducing raw milk grading system and sustained good condition compared with other provinces. High ratio was shown dairy farm in jeju for pre-milking, pre-cooling system equipment and self laboring. Otherwise, the ratio of dairy farm doing test of mastitis is low. The ratio of first grade distribution in Jeju is 80.64%, which means that was improved before introducing raw milk grading system. The number of somatic cells found in summer more than that of other seasons in raw milk. However, these data is a little higher than the nation wide data medium. Also, general components, annual lipid ratio is 3.90% that improved compared with before introducing raw milk grading system. These data showed low in summer and similar to nation wide.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.577-582
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• 2008

The present study has been conducted to study the performance of Dedicated outdoor air handling unit. Dedicated outdoor air handling unit consists of pre-cooler, dehumidification and after cooler. By combining dedicated outdoor air-conditioning and heat pump, a new four-season dedicated outdoor air handling unit has been developed. Amount of energy saved and condition when this new system is superior to conventional vapor-compression cooling system has been presented.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.12
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• pp.1917-1923
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• 2010

This study focuses on model identification and a 2-DOF PID control algorithm for cooling processes; a pneumatic butterfly-type control valve is used for this purpose. The mathematical model is a transfer function composed of a time delay and a second-order delay system. The control valve is identified as a first-order delay system with a time delay and included in the controlled plant. From the experimental data sets for a demo plant, the model parameters are identified, and the 2-DOF PID control gains are analytically derived by Kitamori's method. We show via a computer simulation and an experimental test that the performance of the proposed 2-DOF PID control system is better than that of a conventional 1-DOF PID control system.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.3
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• pp.263-271
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• 2007

The heat transfer coefficient and pressure drop during 9as cooling process of $CO_2$ (R744) in a helically coiled copper tube with the inner diameter of 4.55 mm and outer diameter of 6.35 mm were investigated experimentally. The main components of the refrigerant loop are a receiver, a variable-speed pump. a mass flow meter a pre-heater and a helically coiled type gas cooler (test section). The refrigerant mass fluxes are varied from 200 to $800kg/m^2s$ and the inlet pressures of gas cooler are 7.5 to 10.0 MPa. The heat transfer coefficients of $CO_2$ in a helically coiled tube are higher than those in a horizontal tube. The Pressure drop of $CO_2$ in the gas cooler shows a relatively good agreement with those predicted by Ito's correlation developed for single-phase in a helically coiled tube. The local heat transfer coefficient of $CO_2$ agrees well with the correlation by Pitla et al. However. at the region near pseudo-critical temperature. the experiments indicate higher values than the Pitla et al correlation. Therefore, various experiments in helically coiled tubes have to be conducted and it is necessary to develop the reliable and accurate prediction determining the heat transfer and pressure drop of $CO_2$ in a helically coiled tube.

• Journal of the Korean Solar Energy Society
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• v.40 no.2
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• pp.1-10
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• 2020

Korea government published renewable energy obligation policy that public building must be supplied some part of total consumption energy (2019: 27%, 2020: 30%). RETScreen is freely available global energy tool that developed by Canadian National Energy Laboratory to quantify energy saving to compare conventional system. This program can be performed energy modeling, cost analysis, greenhouse gas emission analysis and financial analysis. In this study, GSHP (Ground source heat pump) heating and cooling system were studied for the energy deliverly and ROI (Return On Investment) in an office building. Three cases were studied according to the number of HP (Heat pump) units for the 1,000㎡ office building located in Daejeon. Results indicated that the energy delivery of the case 1 (1 HP unit) covered 57% of the office building heating and cooling energy consumption. The case 2 (2 HP units) covered 87.8% and the case 3 (3 HP units) covered 96.8% of the office building energy consumption. The ROI of the case 1 indicated 7.9 years. While 8.2 years for the case 2 and 9.7 years for the case 3.

• Special Issue of the Society of Naval Architects of Korea
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• 2013.12a
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• pp.103-109
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• 2013

The Present work focuses on application of Organic Rankine Cycle - Waste heat Recovery System (ORC-WHRS) for marine diesel engine. ORC and its combined cycle with the engine were simulated and its performance was estimated theoretically under the various engine operation conditions and cooling water conditions. The working fluid, R245fa, was selected for the consideration of the heat source temperature, system efficiency and safety issues. According to the thermodynamic analysis, ~13.1% of system efficiency of the cycle was performed and it is about 4% of the mechanical power output of the considering Marine Diesel Engine. Also, addition of evaporator and pre-heater were studied to maximize output power of Organic Rankine Cycle as a waste heat recovery system of the marine diesel engine.

• Proceedings of the KWS Conference
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• 2000.10a
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• pp.166-169
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• 2000

This paper presents a study on the LD Pump laser welded heat transfer and distortion analysis by using finite element method. In the production processing, ferrule and saddle of LD Pump in light-wave communication system are welded by multi mode Nd-YAG laser. Thus distortion happens during laser-welded packaging, and it makes an error of detecting the light signal translated through optical fiber in LD Pump. These parts experience thermal and mechanical hysteresis during heating and cooling process come from laser welding. The amount of final displacement is predicted using the finite element method. And the optimal shape is decided by using the result of pre-analysis.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.165-170
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• 2010

Recently, Interior Permanent Magnet Machine(IPM) is widely used for traction motor in the high speed train. Higher efficiency and power density are the superb performance of IPM. Due to the high power density, however, it has lots of heat source which are originated from copper losses and core losses. These heat source can cause the permanent demagnetization in magnet and the loss of torque and power. To prevent the undesirable loss in the traction motor, the accurate loss calculation and the thermal analysis should be preceded. Especially, the end-winding area and permanent magnet area should be examined correctly. In this paper, the electromagnetic fields were examined by finite element method to analyze the electromagnetic properties of IPM and thermal analysis are carried out with pre-calculated losses. To validate the analysis result, the experiment set with forced air cooling system is manufactured.