• Journal of Advanced Marine Engineering and Technology
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• v.35 no.8
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• pp.1022-1027
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• 2011

A diesel engine works in high compression ratio due to injection of diesel fuel after compression of air. Therefore the engine has a high thermal efficiency, while nitrogen oxide is produced a lot in high flame temperature regions. In order to solve the problem this study HHO gas is added into the intake air of the industrial diesel engine. The test conditions are loads of 0%, 50% and 100% and engine speeds of 700 to 1900 rpm. The results show the maximum torque and pressure is increased, fuel consumption, smoke and CO emissions are decreased and NOx emission is remained at same level.

• International Journal of Automotive Technology
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• v.6 no.4
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• pp.333-340
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• 2005

In order to better quantify the contribution from nonroad sources to emission inventories, it is important to understand not only the emissions rates of these engines but also activity patterns that can be used to accurately portray their in-use operation. To date, however, very little information is available on the actual activity patterns of nonroad equipment. In this study, a total of 18 pieces of nonroad equipment were instrumented with collected data including intake manifold air pressure (MAP), exhaust temperature and, on a subset of vehicles, engine rpm and throttle position. The equipment included backhoes, compactors, dozers, motor graders, loaders and scrappers used in applications such as landfilling, street maintenance and general roadwork. The activity patterns varied considerably depending on the type of equipment and the application. Daily equipment operating time ranged from less than 30 minutes to more than 8 hours, with landfill equipment having the highest daily use. The number of engine starts per day ranged from 3-11 lover the fleet with an average of 5 starts per day. The average percent idle time for the fleet was approximately $25\%$ with a range from 11 to $65\%$ for individual pieces of equipment. Duty cycles based on exhaust temperature/throttle position profiles were also developed for two graders and one dozer.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.6
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• pp.830-836
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• 2003

The classical energy balance method was used to measure the apparent metabolisable energy (AME) of four batches of broiler starter and finisher diets produced by two commercial feed companies. The results showed there was little variation in protein content between batches, but NDF content varied from 13.3% to 15.5% between batches of diet. The batch variation in chemical composition differed between feed manufacturers. While there was no difference in AME and feed conversion ration (FCR) between batches of starter diets produced by company A, FCR and AME ranged from 1.76-1.94 (p<0.001) and 11.38-11.90 MJ/kg air dry (p<0.05), respectively, for diets produced by company B. Similar results were found in a second experiment. There was no difference in AME, dry matter digestibility (DMD) and FCR between batches for finishing diet produced by company B, but a large variation occurred for the finisher diets from company A (p<0.01), where the ranges of FCR, AME and DMD were 1.95-2.30, 10.5-12.3 (MJ/kg air dry) and 58-68%, respectively. FCR was correlated with AME. AME was negatively related to the content of fibre in the diet, but positively related to DMD. The preliminary results based on 24 samples showed that near infrared spectroscopy (NIR) has the potential to predict FCR, intake, AME and DMD of commercial broiler diets, with $R^2$ being 0.93, 0.89, 0.95 and 0.98, respectively. The standard error of cross validation was below 0.2 for AME and only 0.06 for FCR.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.16 no.2
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• pp.110-122
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• 2006

Objective : This study was conducted to quantify chronic lead exposure from various media(ie. working environment, food, ambient air), and to certify the usefulness of exposure assessment using Monte-Carlo simulation in the fields of occupational health. Methods : Data were obtained from Korean Industrial Health Association, Korea Food and Drug Administration, and the Ministry of Environment. Then lead worker's exposure was estimated indirectly from various media and parameters (ie. volume inhaled, body weight, dietary intake, etc.). Uncertainty was analyzed by Monte Carlo simulation with Crystal Ball software. Exposure doses and hazard indices were simulated with various hypothetical scenarios including weekly working hours and respiratory protective equipment. Results : Without respiratory protective equipment, the total exposure dose per kilogram of body weight of lead workers was estimated as $5.45{\times}10^{-3}mg/kg/day$, and hazard index was estimated as 2.26, and exposure contributions were calculated as follows : working environment(82.42 %); foods(17.57 %); and ambient air(0.01 %). But, if working condition has changed - reduction of working hours and using respiratory protective equipment, the total exposure dose per kilogram of body weight was estimated between $1.34{\times}10^{-3}-1.49{\times}10^{-3}mg/kg/day$, and hazard index was estimated between 0.56 - 0.62. Conclusions : This study suggested that occurrence of hazardous impact(ie. increased blood pressure) through lifetime lead exposure would be expected, and that the Monte-Carlo simulation was useful for the fields of occupational health.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.8
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• pp.91-98
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• 1999

This paper describes the air flow characteristics inside the throttle valve. Tow-dimensional steady incompressible Navier-Strokes equation are solved numerically with embedding the conceopt of the artificial compressibility and adopting the Baldwin-Lomax turbulence model. With varying the valve opening angles(the Reynolds number )such as 15$^{\circ}$(5000) , 45$^{\circ}$(3000) , 75$^{\circ}$(7000) and 90$^{\circ}$(10000), respectively. tow cases, with a valve shaft and without one, are analysed. The pressure loss between the entrance and exit is severe at 15$^{\circ}$, 100 times as larger as that of 90$^{\circ}$ case, which also depends much on the existece of the valve shaft. The counter rotating vortices are formed over the valve plate with the shaft at only 75$^{\circ}$. They are smally and very large scale in front and back of the valve shaft , respectively. The velocity profiles of 15$^{\circ}$ and 90$^{\circ}$ at the exit are almost symmetric to the horizontal center line, however, the symmetricity is no longer maintained at 45$^{\circ}$ and 75$^{\circ}$ , and in addition, the flow at 75$^{\circ}$ is enforced a lot below center line. The pressure distribution on the walls is largely changed near the valve shaft, and its magnitude becomes great as the valve angle decreases.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.4
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• pp.31-39
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• 2010

Although driving patterns strongly influence greenhouse gas and air pollutant emission rate from light duty vehicles, emission measurements have been mainly based on chassis dynamometer testing with one standard driving pattern. And there has been limited work on quantifying the independent effect of driving parameters on emission rate because of multidimensional nature of real-world driving pattern. The objective of this study is to obtain the quantitative effect of relative positive acceleration (RPA) on vehicle emission rate. RPA has been used to define the occurrence of acceleration demanding large amounts of power in certain driving distance and shown to be a significant affecting parameter for real-world emission rate. 40 driving patterns have been developed with fixed driving parameters to investigate independent effect of RPA. For the same values of average vehicle speed and power, the trend in carbon dioxide emission rate and fuel consumption with respect to RPA is very clear. Emission rate of nitrogen oxide and particulate matter also increase with respect to RPA, but the trend is less clear. Carbon dioxide emission from diesel vehicle appear to be more affected by high accelerations compared to that from gasoline vehicle because of high intake air restriction during acceleration caused by turbocharger and intercooler. The results have implications for the possible reduction of environmental effects through better traffic planning and management, driver education and car design.

• The Journal of Engineering Research
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• v.2 no.1
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• pp.125-131
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• 1997

The regenerator is important part of the glass melting furnace to increase the temperature of the intake air through the combustion flame. The insulation, checker brick, prevention of the air leak has been studied to decrease the fuel consumption in glass melting industries. Thus the new types of checker brick and the design of the rider arch has been studied to prolong the life of the glass melting furnace. The height of the regenerator increased from 5.64 m to 7.89 m in the reforming of the glass melting furnace. Thus the stability of the rider arch is studied under the condition of increased load of checker brick in this research. The rider arch was estimated to be stable inspite of the increase of load according to the calculation. The max. sustained compressive stress of the rider arch is 163 kg/$cm^2$ and the max. sustained shear stress is 6.37 kg/$cm^2$.

• Journal of Aerospace System Engineering
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• v.11 no.2
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• pp.43-50
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• 2017

The sea of the Korean peninsula has undergone various marine changes, including naval vessels, naval operational aircrafts, air force fighters, coastal airports and airfields. In particular, salt directly affected by the marine environment, equipment operating under a high temperature / high speed as the gas turbine is the high temperature corrosion (Hot Corrosion) caused by sulfur components and salinity of the fuel used. When the height of the demister (air intake) is less than 7 m, the salinity of the salt entering the sea increases and the corrosion increases rapidly. In addition, the weapon systems operating in the East Sea than in the West Sea showed a 17% increase in the corrosion rate due to the relatively high salinity scattered by saline, wind, and wave. In order to minimize the salinity inflow, it should be operated at more than 13 m from the sea to minimize rapid hot corrosion.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.137-138
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• 2017

The sea of the Korean peninsula has various marine changes, including naval vessels, naval operational aircrafts, air force fighters, coastal airports and airfields. In particular salt directly affected by the marine environment, equipment operating in a high temperature / high speed as the gas turbine is the high temperature corrosion(Hot Corrosion) caused by sulfur components and salinity of the fuel used. When the height of the demister (air intake) is less than 7m, the salinity entering the sea increases and the corrosion increases rapidly. In addition, the weapon systems operating in the East Sea than the West Sea showed a 17% increase in corrosion rate due to the relatively high salinity scattered by saline, wind, and wave. In order to minimize the salinity inflow, it should be operated at more than 13m from the sea to minimize rapid hot corrosion.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.1160-1164
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• 2017

In this research, a high altitude simulating test facility is designed using vacuum pump system composed of roots pumps and screw pumps. Air flow rate and chamber pressure are 1 kg/s and 2500 Pa, respectively. To design the test facility, experimental tests using certain pump combinations are performed for air injection of the order of hundreds of g/s. From the tests, it is found that 11 roots pumps and 33 screw pumps are required for the considered test facility. Test results are compared with theoretically estimated values. However, intake capacity theoretically estimated is found to be 20 percent larger than test results. This is thought because of higher pressure difference of roots pump for test conditions. Therefore, if more screw pumps are added for the considered pump system, it would be possible to lower the vacuum level of test chamber.