• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1330-1335
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• 2007

The HVAC and the air duct is to make optimal indoor environment. By the HVAC position, method and the air duct construction, the important elements can affect on cooling performance, passengers' convenience, and energy efficiency. According to this, there are features, such as the indoor temperature distribution, cooling performance, velocity distribution from diffuser, tend to be come out variously. Also, comparing and analysing temperature distribution, cooling performance, air velocity, noise based on the real practical vehicle tests, it shows features in detail. Besides, it can lead to make design the system of HVAC & air duct effectively.

• Analytical Science and Technology
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• v.14 no.6
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• pp.516-521
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• 2001

This research was for reducing leachated concentration of hazardous pollutants in bottom ash from municipal solid waste combustors(200 tons/day) of Korea. Lead and copper compounds were selected as main pollutants. For reducing of leachated level, optimal conditions were observed using air oxidation for lead compounds and water washing method for copper compounds. and it was observed stable pH range of bottom ash from analyzing lechated level by pH variation.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.2
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• pp.164-168
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• 2013

Objectives: This study was aimed at the examination of the lead exposure status of smelting process workers in steelmaking using scrap iron. Methods: The study was conducted from July to September 2012 by means of measurements taken during the smelting process, with 45 minutes set for a one-time smelting work cycle when it comes to personal air sample and area air sample. As such, daily work hours were classified into 360 minutes for measurement. The analysis of lead concentration was conducted using AAs based on the NIOSH 7300 method. Results: In the case of the personal specimens that were subjected to periodical measurement 45 minutes per one session during the smelting process, 40 out of 42 specimens measured were found to contain lead, with an average concentration level of $0.028mg/m^3$ (Max: $0.182mg/m^3$, Min: $0.005mg/m^3$, TWA-more than 50%: 4 out of 6 units). In the case of regional specimens, lead was detected in 45 out of 48 specimens measured, with an average concentration level of $0.037mg/m^3$ (Max: $0.220mg/m^3$, Min: $0.007mg/m^3$ ). In the case of regional specimens subjected to measurement using a day as the work cycle, lead was detected in 15 out of 15 specimens measured, with an average concentration level of $0.049mg/m^3$ (Max: $0.478mg/m^3$, Min: $0.005mg/m^3$ ). Conclusions: It concluded that smelting process workers in steelmaking are exposed to lead because scrap iron is used as a raw material. It is thus necessary to introduce legal management to prevent occupation-related disease in smelting process workers in steelmaking.

• Journal of Preventive Medicine and Public Health
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• v.29 no.1 s.52
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• pp.15-26
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• 1996

It has been studied that a variety of fauna and flora are sensitive biological indicators which reflect the severity of regional pollution of heavy metals, but in the center of part of Taegu City the controversial issue of lead poisoning attributable to the atmosphere which contains an increased concentrations of lead has been raised recently, it is usually hard to find suitable plants or animal in the areas with heavy traffic. Pigeons are ubiquitous in and around Taegu City area, inhabiting even the most densely populated areas with heavy traffic. With its small body size, high metabolic turnover, and rather limited mobility, a pigeon, as a biological indicator is expected. This study was conducted to monitor lead pollution in the Taegu and Kyongju City in Korea. We measured the lead content of the various tissue of three groups of feral pigeon(Columba livia) and soil and atmospheric lead concentration. First group was obtained in heavy traffic area in Taegu City, the second group was obtained a park in Taegu City and the third group was obtained light traffic area in Kyongju City. The air and soil lead concentration of heavy traffic area in Taegu City was $0.11{\mu}g/m^3,\;4.96{\mu}g/g$, that of park in Taegu City was $0.05{\mu}g/m^3,\;2.65{\mu}g/g$ and that of light traffic area in Kyongju City was $0.03{\mu}g/m^3,\;0.01{\mu}g/g$. The lead content of lung, blood, kidney, femur and liver of feral pigeons in heavy traffic area in Taegu City was significantly higher than pigeons obtained in a park in Taegu City and low traffic density area in Kyongju City(p<0.01). But stomach lead content of three group did not reflect a significant difference. In this study positive correlation was found between atmospheric lead concentrations and the concentration of lead in the pigeon's lung(r=0.5040, p<0.001), blood(r=0.3322, p<0.01), kidney(r=0.4824, p<0.001), femur(r=0.7214, p<0.001) and liver(r=0.4836, p<0.01). We can also found positive correlation between soil lead concentrations and the concentration of lead in the pigeon's femur(r=0.4850, p<0.001), kidney(r=0.4850, p<0.001) and liver(r=0.4386, p<0.01). In the pigeon's tissue there were significant correlations between concentration of lead in the blood and kidney(r=4818, p<0.001), femur(r=0.6157, p<0.001) and liver(r=0.3889, p<0.001). In conclusion, at the heavy traffic area in Taegu City, lead concentrations found in the atmosphere and soil are reflected in the lead concentrations of different tissue of urban pigeons. It is suggested that the tissue of pigeons can be good biological indicators of environmental lead pollution.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2003.10a
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• pp.161-161
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• 2003

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2004.11a
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• pp.349-350
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• 2004

• Journal of Digital Contents Society
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• v.14 no.4
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• pp.521-528
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• 2013

Recently the increasing numbers of cars and traffic jamming makes air pollution condition more severely. Especially high-density population area, in most big cities like Bejing and Seoul, can lead to lung illness and other diseases. In this study to decrease this kind of air pollution condition, a method of air pollution information transmission is proposed. For the transmission of air pollution and traffic control data, international standard technology, the TPEG is applied.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.4
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• pp.603-609
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• 2008

Slotless linear brushless DC motor are widely used in precision machine applications because of their advantages such as low of detent force, negligible iron loss. But they have a disadvantage such as low thrust density, thrust ripple, and excessive use of permanent magnet materials. These lead to undesirable performance and high production cost. In this paper, we deal with the design and characteristics investigation of a air-core tubular linear brushless DC(TLBLDC) motor with air-core stator and permanent magnet mover. And to investigate the static and dynamic characteristics of air-core TLBLDC motor, the prototype machine is manufactured and analyzed by F.E.M. and Matlab simulink simulations. Especially, dynamic characteristics of air-core TLBLDC motor driven with 6 step inverter are simulated by F.E.M.coupling with external circuit and Matlab simulink program, and measured for the prototype motor. The simulation results are compared to the experimental results such as current waves, thrust and speed curve.

• 대한예방의학회:학술대회논문집
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• 1995.10a
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• pp.379-380
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• 1995

• Journal of the Korean institute of surface engineering
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• v.36 no.5
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• pp.373-378
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• 2003

With increasing environmental concerns, application of lead-free solder and fluxless soldering process have been taken attention from the electronic packaging industry. Plasma treatment is one of the soldering methods for the fluxless soldering, and it can prevent environmental pollution cased by flux. On this study fluxless soldering process under $Ar-H_2$plasma using lead free solders such as Sn-3.5 wt%Ag, Sn-3.5 wt%Ag-0.7 wt%Cu and Sn-37%Pb for a reference was investigated. As the plasma reflow has higher soldering temperature than normal air reflow, the effects of UBM(Under Bump Metallization) thickness on the interfacial reaction and bonding strength can be critical. Experimental results showed in case of the thin UBM, Au(20 nm)/Cu(0.3 $\mu\textrm{m}$)/Ni(0.4 $\mu\textrm{m}$)/Al(0.4 $\mu\textrm{m}$), shear strength of the soldered joint was relatively low as 19-27㎫, and it's caused by the crack observed along the bonded interface. The crack was believed to be produced by the exhaustion of the thin UBM-layer due to the excessive reaction with solder under plasma. However, in case of thick UBM, Au(20 nm)/Cu(4 $\mu\textrm{m}$)/Ni(4 $\mu\textrm{m}$)/Al(0.4 $\mu\textrm{m}$), the bonded interface was sound without any crack and shear strength gives 32∼42㎫. Thus, by increasing UBM thickness in this study the shear strength can be improved to 50∼70%. Fluxed reflow soldering under hot air was also carried out for a reference, and the shear strength was 48∼52㎫. Consequently the fluxless soldering with plasma showed around 65∼80% as those of fluxed air reflow, and the possibility of the $Ar-H_2$ plasma reflow was evaluated.