• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.6
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• pp.52-60
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• 2012

Minimizing the cylinder wear and the consumption rate of cylinder oil in a large two-stroke diesel engine is of great economic importance. A motor-driven cylinder lubricator for Sulzer RT-flex large two-stroke diesel engines developed by authors is in need of modifying the lubricating system to lubricate cylinder parts optimally by an electronically controlled quill device according to changes of engine load and revolution speed. In order to apply the developed accumulating distributor to an integrated cylinder lubricator by the electronically controlled system as the third research stage, the lubricating system is improved in the electronically controlled quill device with a solenoid valve. In this study, the effects of lubricator revolution speed, driving pressure and cylinder back pressure on oil feed rate, maximum discharge and delivery pressures are experimentally investigated by using the integrated cylinder lubricator system with an accumulated distribution by the electronic control. It is found that the oil feed rate of the developed integral cylinder lubricator system is less than that of the motor-driven cylinder lubricator by the electronically controlled quill system equipped with an accumulating distributor because of the decrease of delivery speed by increasing the maximum delivery pressure in the same experimental condition.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.2
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• pp.115-125
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• 2007

Minimizing the cylinder wear and the consumption rate of cylinder oil in a large two-stroke marine diesel engine is of great economic importance. In Korea, a motor-driven cylinder lubricator for a large two-stroke marine diesel engine manufactured by $W{\ddot{a}}rtsil{\ddot{a}}$ Switzerland Co., Ltd. was first developed by authors through the joint research of industry-university in 2002. The characteristic of the developed product is that can control automatically the oil feed rate to a load fluctuation by the motor drive and the offset cam. The performance of the product is not also inferior to the conventional one. For manufacturing the reliable and useful products, however, it is necessary to investigate further characteristics and improve the performance of a cylinder lubricator. In this study, the effect of quill with and without accumulator on maximum discharge pressure, delivery delay duration and oil feed rate relative to motor revolution speed using plunger stroke as a parameter is experimentally investigated by using the developed cylinder lubricator. It is found that the maximum discharge pressure with accumulator is higher than that of no accumulator as plunger stroke and motor revolution speed are elevated, and the delivery delay duration with accumulator is shorter than that of no accumulator as plunger stroke and motor revolution speed are increased. Also, oil feed rate with accumulator is less than that of no accumulator except for a plunger stroke of 2 mm as plunger stroke and motor revolution speed are raised.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.6
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• pp.848-854
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• 2005

We examined the effect of dietary Turkish propolis and flavomycin on growth performance, carcass characteristics, internal organ weights and some serum variables in quail (Coturnix coturnix japonica) birds. One hundred and fifty day-old quails were randomly divided into five groups, with ten replicate pens per treatment and three birds per pen. One group received the basal diet (antibiotic-free), the control. The flavomycin at 10 mg/kg diet and propolis at 0.5, 1 and 1.5 g/kg diet were added to the basal diet. Body weight gain, feed consumption and feed efficiency were determinated weekly. Carcass characteristics, internal organ weights and serum variables were determinated at the end of the study (35 day). The results showed that body weight gain, feed efficiency and carcass weight were improved significantly (p<0.01) when compared to control group for birds fed diets containing propolis and flavomycin between 14 to 35 days. The addition of 1 g/kg propolis to the diet resulted in significantly (p<0.01) better-feed efficiency as compared to control and other treatment groups. There were no significant differences in carcass yield, abdominal fat, liver gizzard, proventriculus and intestinal weight and intestinal pH among the groups. In addition, serum ALP, total protein, uric acid, cholesterol and triglyceride were not influenced by the any supplementation. However, birds fed with propolis tended to have higher serum HDL and lower level than birds fed the control diet. In conclusion, supplementation of propolis and flavomycin during the growth period showed similar effects on growth performance in quail. Therefore, it can serve as a natiral substitute for antibiotics in poultry diets.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.5
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• pp.19-28
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• 2005

It is of great economic importance to minimize the cylinder wear and the consumption rate of cylinder oil in a large two-stroke diesel engine. The motor-driven cylinder lubricator was first developed fur a large two-stroke marine diesel engine made in $W{\ddot{a}}rtsil{\ddot{a}}a$ Switzerland Ltd. by the joint research of industry-university. In this study, the effects of revolution speed, plunger stroke and cylinder back pressure on maximum discharge and delivery pressures, delivery delay duration, and oil feed rate are experimentally investigated by the home-manufactured cylinder lubricator. The maximum discharge pressure with a spot of 0.03 m and the maximum loss pressure at spots of 5, 6.78 and i 0 m away from the end of lubricator slot are increased as plunger stroke, revolution speed and back pressure are elevated, and the delivery delay duration is shortened as plunger stroke, revolution speed and oil pipe length are increased. Also, oil feed rate is increased as plunger stroke and revolution speed are raised, but lowered as the back pressure is increased.

• Korean Journal of Veterinary Research
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• v.44 no.4
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• pp.593-605
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• 2004

An egg has been considered as one of the most important food sources because of it's nutritional superiority and reasonable price. With the complexity of egg flow system from production to consumption in Korea, preventive measures for egg safety have been required. Therefore, our study was carried out to analyze hazards for the egg under farm level and develope preventive measures with a purpose of obtaining egg safety. To analyze biological hazards, microbial contamination of egg(normal, dirty and cracked), water, feed, manure and equipments associated with laying were investigated. One isolate of Salmonella enteritidis and S. bardo were detected from the manure and dirty egg shell respectively. The sanitary conditions in the farm were surveyed by questionaries. Confirmation of vaccination for purchasing chicks and establishment of sanitary guidances for water and type of water suppliers ought to be preceded. Feed supplier systems including feed tanks, feed pipes and hoppers were known that their contamination might give it a chance to infect individuals and egg content and shell. The safe and rapid disposal of dead chickens and rodent were reported as more crucial factors to prevent infectious disease and manage good sanitation. Egg selector and collecting belt should be kept properly not to be contaminated from egg fluids and feces. It should be also considered that regular gathering of eggs, removal of dirty or cracked ones, storage under refrigeration and the use of disposable egg tray were continuously fulfilled. Conclusively, Our results suggested that HACCP-based system for providing fresh and safe eggs to consumers should be applied to the farm.

• Transactions of the Korean hydrogen and new energy society
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• v.30 no.4
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• pp.356-361
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• 2019

Since the government announced the roadmap to revitalize the hydrogen economy, we are constantly making the effort to expand the use of fuel cell electric vehicles (FCEV) and hydrogen charging stations. There is however a significant issue to build and operate the hydrogen charging station due to the lack of the profit model. Many researchers believe that the supply of FCEV will be increased in the near future and finally ensure the economy of hydrogen charging stations. This study shows that the sales changes of hydrogen gas and consumption patterns by the operation of the hydrogen charging station in Changwon City. The results will be used as the evidence to support for operating the hydrogen charging station by private businesses and the validity of additional establishment of hydrogen charging stations.

• Journal of Animal Science and Technology
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• v.65 no.3
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• pp.479-489
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• 2023

Livestock production depends on the utilization of nutrients, and when this is accomplished, there is accelerated momentum toward growth with a low cost-to-feed ratio. Public concern over the consumption of pork with antibiotic residues in animals fed antibiotic growth promoters (AGP) has paved the way for using other natural additives to antibiotics, such as herbs and their products, probiotics, prebiotics, etc. Numerous feed additives are trending to achieve this goal, and a classic example is vitamins and minerals. Vitamins and minerals represent a relatively small percentage of the diet, but they are critical to animal health, well-being, and performance; both play a well-defined role in metabolism, and their requirements can vary depending on the physiological stage of the animals. At the same time, the absence of these vitamins and minerals in animal feed can impair the growth and development of muscles and bones. Most commercial feeds contain vitamins and trace minerals that meet nutrient requirements recommended by National Research Council and animal feeding standards. However, the potential variability and bioavailability of vitamins and trace elements in animal feeds remain controversial because daily feed intake varies, and vitamins are degraded by transportation, storage, and processing. Accordingly, the requirement for vitamins and minerals may need to be adjusted to reflect increased production levels, yet the information presented on this topic is still limited. Therefore, this review focuses on the role and function of different sources of minerals, the mode of action, the general need for micro and macro minerals in non-ruminant diets, and how they improve animal performance.

• Journal of Radiation Protection and Research
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• v.24 no.2
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• pp.73-86
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• 1999

The ion-exchange method for the purification of primary coolant has been used broadly in PWR(pressurized water reactor)-type nuclear power plants due to its high decontamination efficiency, simple system, and easy operation. However, its non-selective removal of metal and non-radionuclides shortens its life, resulting in the generation of a large amount of waste ion-exchange resin. In this study, the feasibility of electrodeionization (EDI) was investigated for the purification of primary cooling water using synthetic solutions under various experimental conditions as an alternative method for the ion exchange. The results shows that as the feed flow-rate increased, the removal efficiency increased and the power consumption decreased. The removal rate was observed as a 1000 decontamination factor(DF) at a nearly constant level. For the synthetic solution of 3 ppm TDS (Total Dissolved Solid), the power consumption was 40.3 mWh/L at 2.0 L/min of feed flow rate. The higher removal rate of metal species and lower power consumption were obtained with greater resin volume per diluting compartment. However, the flow rate of the EDI process decreased with the elapsed time because of the hydrodynamic resistivity of resin itself and resin fouling by suspended solids. Thus, the ion-exchange resin was replaced by an ion-conducting spacer in order to overcome the drawback. The system equipped with the ion-conducting spacer resolved the problem of the decreasing flow rate but showed a lower efficiency in terms of the power consumption, the removal rate of metal species and current efficiency. In the repeated batch operation, it was found that the removal efficiency of metal species was stably maintained at DF 1000.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.2
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• pp.215-222
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• 2015

The objective of this research was to evaluate the growth performance, the apparent ileal digestibility of nitrogen and energy, the retention of nutrients and the apparent metabolizable energy corrected to zero nitrogen retention (AMEn) in broiler chickens supplemented with increasing doses of a worm leachate (WL) as a source of humic substances (HS) in the drinking water. In Exp. 1, 140 male broilers were penned individually and assigned to four WL levels (0%, 10%, 20%, and 30%) mixed in the drinking water from 21 to 49 days of age. Water was offered in plastic bottles tied to the cage. In Exp. 2, 600 male broilers from 21 to 49 days of age housed in floor pens were assigned to three levels of WL (0%, 10%, and 20%) mixed in the drinking water. The WL was mixed with tap water in plastic containers connected by plastic tubing to bell drinkers. The results of both experiments were subjected to analysis of variance and polynomial contrasts. In Exp. 1, the daily water consumption was similar among treatments but the consumption of humic, fulvic, and total humic acids increased linearly (p<0.01) as the WL increased in the drinking water. The feed conversion (p<0.01) and the ileal digestibility of energy, the excretion of dry matter and energy, the retention of dry matter, ash and nitrogen and the AMEn showed quadratic responses (p<0.05) relative to the WL levels in drinking water. In Exp. 2, the increasing level of WL in the drinking water had quadratic effects on the final body weight, daily weight gain and feed conversion ratio (p<0.05). The addition of WL as a source of HS in the drinking water had beneficial effects on the growth performance, ileal digestibility of energy, the retention of nutrients as well on the AMEn in broiler chickens; the best results were observed when the WL was mixed at levels of 20% to 30% in the drinking water.

• Korean Journal of Veterinary Research
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• v.54 no.2
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• pp.81-86
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• 2014

In this study, trends in the sales of antimicrobials for use in livestock facilities and fisheries from 2003 to 2012 were investigated with regard to antimicrobial group, antimicrobial usage, and animal species. The overall amount of antimicrobials sold each year from 2003 to 2007 was 1,500 tons, after which they decreased, with the lowest sales being 936 tons in 2012. The total volume of antimicrobials used for feed additives decreased markedly by 94% from 2003 to 2012, which was mainly attributed to banning of feed additives. However, antimicrobial consumption through self prescription by farmers for disease prevention and treatment increased by 25% from 2003 to 2012. The largest volume of antimicrobials sold was for use in pigs (48~57%), followed by poultry (18~24%), fisheries (11~25%), and cattle (5~8%). Tetracycline was the highest selling antimicrobial, followed by penicillins and sulfonamides, although the overall sale of all three antimicrobials gradually decreased over the study period. This study demonstrated that the total consumption of antimicrobials has gradually decreased since 2008. Nevertheless, usage by nonprofessionals increased, which can ultimately cause emergence and spread of antimicrobial resistance. Thus, early establishment of veterinary prescription guidelines for prudent use of antimicrobials is urgently needed in Korea.