• Fisheries and Aquatic Sciences
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• v.21 no.7
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• pp.25.1-25.6
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• 2018

The main objective of this study was to provide anesthetic criteria of clove oil for an effective manipulation and transportation of red spotted grouper, Epinephelus akaara. When anesthesia temperature (20, 24, and $28^{\circ}C$) and concentration of clove oil (25, 50, and 75 ppm) were increased, the anesthesia and recovery time decreased and tended to be similar to each other between juvenile and adult. Also, as the temperature and concentration increased, the ratio of exposure time and recovery time between juvenile and adult were decreased. When plasma cortisol concentrations were compared for 48 h after anesthesia with 50 ppm of clove oil, both the juvenile and adult fish grew up to 12 h; however, thereafter decreased and there was no significant difference from control at 48 h.

• Journal of Energy Engineering
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• v.28 no.1
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• pp.30-36
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• 2019

The military has developed and operated a variety of military vehicles. Among them, medium tactical vehicles are developed as vehicles suitable for transporting troops, replacing existing military trucks, which have a significant impact on infantry forces' combat capability. Applying technology to increase fuel efficiency to these critical weapons systems, medium tactical vehicles, increases the distance range, which can reduce effective operational performance and oil costs. In this study, a measure was taken to improve the distance range of Medium Tactical Vehicles by applying an oil temperature control strategy to increase fuel efficiency.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.10a
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• pp.233-236
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• 2003

In this Paper, the temperature control error and cooling characteristics of inverter typ coolers are evaluated to predict application validity of coolers under heating pattern and amount The temperature control error of coolers small in 15~70% range of the max. cooling ability. At less than 15% of max. cooling ability has the inverter type cooler a basic temperature control error $\pm0.5^{\circ}C$ and acts as on/off type coolers. The inverter type cooler is unsuitable for precision temperature control under the complex heating pattern. But PID control of cooler including the heating system is an alternative for the case.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.3
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• pp.216-219
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• 2000

A field study was carried out to compare the performances of mulching with recycled paper, oil-treated paper and urea-coated paper in spring season potato culture. Soil temperature, weed occurrence, and the growth and yield of potato (cv. Sumi) were compared with unmulched control. The average soil temperatures at 5cm soil depth during the first 10 days after planting were 18.9$^{\circ}C$, under paper mulch and 20.6$^{\circ}C$, under oil-treated paper mulch, being lower 0.8$^{\circ}C$ and higher 1.2$^{\circ}C$, respectively, than unmulched control. Paper mulch lowered maximum soil temperature by 4.6$^{\circ}C$, on a fine day, while oil-treated paper mulch elevated it by over 6.6$^{\circ}C$, Urea-coated paper was decomposed fester than the mulch paper without urea coating. The former was decomposed 50% by 80days after mulching, but the later only 20%. In all mulch treatments, weeds were effectively controled throughout the potato growing season. The percent emergence of potato was not different significantly among treatments. However, a little lower emergence and poor early growth were observed under oil-treated paper mulch because of higher soil temperature. Except oil-treated paper mulch, the paper mulches with and without urea coating showed no difference in growth and yield of potato from the unmulched control. The growth and yield performances were poorest under oil-treated paper mulch. Oil-treated paper mulch would result in difference growth and yield performances if potato is planted earlier than April IS in the present experiment. Further researches are needed for this aspect.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11b
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• pp.498-505
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• 2000

Performance of a hydraulic system is influenced by its working temperature. Therefore, it is very important to make the system perform uniformly in an entire range of the working temperature. In this study a simulation of a hydraulic control system for the powershift transmission of tractors was conducted and the effect of the temperature was investigated in terms of design conditions of the system. Results of the simulation are as follows. The hydraulic control system with a spring accumulator was found to be more convenient to control the shifting time than that with a gas accumulator. By returning the oil from the clutches to the system through a path between the filter and pump, the time delay due to the pressure difference between the low and high temperatures could be reduced. Therefore, it was recommended that the hydraulic control system for the powershift transmission of tractors must be equipped with a spring accumulator and a circuit to return oil from the clutches to the system through a path between the filter and pump.

• Development and Reproduction
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• v.23 no.1
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• pp.21-34
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• 2019

The effects of the anaesthetic agents, clove oil and mixture of clove oil with lidocaine-HCl were evaluated on river puffer, Takifugu obscurus and tiger puffer, T. rubripes. Anaesthesia times of clove oil were affected by water temperature ($20^{\circ}C$, $24^{\circ}C$, and $28^{\circ}C$) and salinity (10, 20, and 30 ppt). Anaesthesia times of mixed samples were significantly similar with regard to exposure and recovery times, and all samples satisfied anaesthesia criteria (exposure time within 3 min and recovery time within 5 min) under the various temperatures and salinities, and the lowest to highest concentration of anaesthetics (p<0.05). Both species river puffer and tiger puffer had short exposure time with a high anaesthesia dose, high temperature ($28^{\circ}C$) and intermediate salinity (20 ppt), and were highly affected by temperature and salinity (p<0.05). The mixed anaesthetics had rapid exposure times and long recovery times in contrast to the effects of clove oil. Cortisol concentrations under the conditions of various clove oil dosages, salinity, and temperature for both species increased until 12 hrs after recovery from anaesthesia (p<0.05). After 12 hrs, cortisol concentrations decreased until after 48 hrs (p<0.05). During the simulated transportation of both species, control and sedated clove oil groups (5 ppm) were measured for water parameters, dissolved oxygen (DO), $CO_2$, respiratory frequency, $NH_4{^+}$, and pH for 6 hrs in 1 hr intervals. Water parameters of sedated groups and controls were significantly different after 2 hrs (p<0.05).

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.10a
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• pp.277-277
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• 2003

• Journal of Ocean Engineering and Technology
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• v.33 no.2
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• pp.139-145
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• 2019

It is important that an MGO Chiller System, which is one of the sulfur oxide emission control technologies, is designed to meet the fuel temperature requirements, even with sudden engine load changes. Three different control algorithms (PI, Cascade, and MPC) were applied to an indirect MGO chiller system to compare and analyze the outlet temperature dynamic characteristics of the system through a case study. The results showed that the MPC control method had the best temperature following characteristics in the case study, and the temperature deviation range was reduced by approximately 5% compared to the PI control method.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.3
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• pp.168-172
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• 2013

A preliminary performance test of a 30RT 2-stage screw heat pump was carried out in order to develop a high performance large-scale unutilized energy source heat pump system, which will be used for district heating and cooling. In this study, two issues of the system operating control were investigated. The first issue is the mode switching control from 1-stage to 2-stage. A stable 2-stage heating operation is guaranteed, only if the load-side water inlet temperature is over a certain value, where the 1-stage heating operation should be done first from a cold start. The second issue is oil level control. An oil shortage problem in the low stage compressor, which depends on the degree of suction superheat, was solved by a proper oil level control scheme.

• Journal of Power System Engineering
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• v.6 no.2
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• pp.82-87
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• 2002

For the dynamic behavior evaluation of a semi-active vibration control system, it is very important to use an accurate mathematical model for the hydraulic damper applied to the control system. In this study, a mathematical model for a symmetric type hydraulic damper was suggested. In this model, the effects of gas volume and oil temperature variation on the bulk modulus of oil were considered. The dynamic behavior of the damper was investigated by experiments and simulations. It was confirmed that the pressure variation, damping force, and mean pressure variation could be estimated with comparatively good precision by the suggested mathematical model. Moreover, it was shown that excessive pressure rise can be generated by the oil expansion due to the heat energy transformed from the exciting energy of the damper for a short period of the damper operation.