• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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• pp.235-238
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• 2004

유류 오염토양에 대한 과산화수소의 화학적 고도산화에 대한 실험실 및 현장 적용 가능성을 타진하였다. 현장 오염토양 10g에 각각 과산화수소(34.5%) 원액을 중량비로 0.3%, 0.6%, 1.0%, 2.0%를 처리하여 혼합 후 실험실에서 1일 반응 후 TPH 농도를 분석하였다. 분석결과 토양 대비 2.0%의 과산화수소를 투입한 처리구에서 가장 높은 복원 효율을 측정할 수 있었고 2.0%까지의 투입농도에서 미생물의 농도 변화는 측정되지 않았다. 오염된 토양에 과산화수소를 오염 토양 중량 대비 2%를 분무기로 살포 후 로타리가 설치된 경작 장비로 뒤집기 수행하여 1일 후 오염토양의 오염농도를 분석한 결과 초기 TPH 5,365ppm의 농도가 2,317ppm으로 56.8% 복원된 것을 확인할 수 있었다.

• Journal of Biosystems Engineering
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• 제23권5호
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• pp.427-438
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• 1998

In Korea, rotary implements are mainly utilized in the tillage operation. The attitude control system for rolling phenominon of tractors, which in caused due to uneven ground surfaces and sinkage of tractor wheels, is one of the most important control systems in agricultural tractors. The attitude control system of a rotary implement, attached on tractors, was designed and fabricated in this study. The control system was largely composed of four main units; a setting unit, a detection unit, a controller and a hydraulic unit. The implement was controlled by control signals from a computer proportional to controlled errors, on/off action of two directional solenoide valve and lift cylinder on the right lift rod. Response characteristic experiments for the control system fabricated in this study were carried out indoors and outdoors. The results of experiments showed the response characteristics sufficient to use as the attitude control system of rotary implements for agricultural tractors.

• 한국연소학회지
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• 제12권3호
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• pp.24-32
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• 2007

A theoretical model was developed for rotary kiln and computational study was conducted to find the effect of feeding characteristics. One dimensional model with the variations of heating distribution, length of heating zone, excess air ratio and revolution was considered. The comparison of parallel-flow rotary kiln with that of counter-flow was conducted. For parallel-flow type, it is found that the variation of temperature of solid is not great for the zone that is following flame-heating zone. This zone is good to take the special treatment because thermal deviation is small and contacting time is enough for another treatment. Increase of excess air ratio have the effect of decreasing solid temperature. But this effect of decreasing solid temperature goes small for the great excess air ratio. The heating is efficient for the flame which has the maximum heating at the central region of the full length.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1998년도 제27회 춘계학술대회
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• pp.77-82
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• 1998

The Part of slot on rotary compressor which plays an important part of the reliability and performance is studied on machinability and the wear characteristics for the specimen made by sand mold and permanent mold. The experiment are used the face cutter of milling machine which make the processing surface like broaching process and rollblock wear test machine. Permanent-mold casting iron is not affected by variation of RPM of milling machine, but sand-mold cast-iron is improved to increasing RPM. Also sand-mold casting iron shows superior wear characteristic to permanent-mold casting iron. This results from harder matrix of pearlite structure and self-lubrication characteristics of graphite. And wear particles in tested oil show shape and size similar to severe wear particles of oil taken from rotary compressor. The material and surface condition of slot play important part of the reliability and performance.

• 한국공작기계학회논문집
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• 제11권5호
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• pp.58-64
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• 2002

Mirror surface finish of Si-wafers has been achieved by rotary in-feed machining with cup-type wheels in ELID grinding. But the diameter of the workpiece is limited with the diameter of the grinding wheel in the in-feed machining method. In this study, some finding experiments by the rotary surface grinding machine with straight type wheels were conducted, by which the possible grinding area of the workpiece is independent of the diameter of the wheels. For the purpose of investigating the grinding characteristics of large scale diametrical silicon wafer, grinding conditions such as rotation speed of grinding wheels and revolution of workpieces are varied, and grinding machine used in this experiment is rotary type surface grinding m/c equipment with an ELID unit. The surface ground using the SD8000 wheels showed that mirror like surface roughness can be attained near 2~6 nm in Ra.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.560-563
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• 1997

Sound intensity method is well known as a visualization technique of sound field and sound propagation in noise control. Sound intensity is a vector quantity that describes the magnitude and the direction of net flow of acoustic energy at a given position. The current measuring method is expensive and difficult to identify the noise source exactly. In this paper, we have studied the noise source identification and the characteristics of noise source of rotary compressor for air conditioner using complex sound intensity method. The new method for instantaneous sound intensity is also proposed and it is useful for transient state and steady state. The criteria of these states select auto correlation coefficient. The advantage, simplicity and economic attribution of this method are verified by analyzing the characteristics of noise source with instantaneous sound intensity compared to mean sound intensity.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문초록집
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• pp.385.2-385
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• 2002

Hermetic rotary compressor is one of the most important components for air conditioning system since it has a great effect on both the performance and the noise and vibration of the system. Noise and vibration of rotary compressor is occurred due to gas pulsation during compression process and unbalanced dynamic force. In order to reduce noise and vibration, it is necessary to identify sources of noise and vibration and effectively control them. (omitted)

• 한국기계가공학회지
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• 제3권3호
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• pp.11-16
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• 2004

In this study, the characteristics of signals such as acoustic emission, vibration amplitude and noise level which are derived from the abnormal condition of compressor are investigated. The normal condition, vane stick sound and roller defect condition are chosen to analyze the signal in each cases. From the feature extraction of each signals, the dominant parameters of each signals which can identify the abnormal condition are suggested.

• 한국기계가공학회지
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• 제8권4호
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• pp.61-68
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• 2009

This paper presents the numerical analysis of process of sludge drying to know the characteristics of design parameters and develop the new process plant. Finite volume method and $k-{\varepsilon}$ turbulence model were used to analogy the sludge drying furnace. It has been attempted to perform the disposal of sewage sludge such as simple reclaiming and dumping in sea and incineration. Currently, these methods are restricted by national or international government regulations. The drying process is adopted as an effective method for sewage sludge treatment. However sewage sludge makes it difficult to treat with a large volume at the real drying process plant because of its own complicated physical, chemical, and thermal properties. The final design value of moisture content with 10% of the dried sludge can be obtained through the simulated outputs in this study.

• 한국자동차공학회논문집
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• 제4권4호
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• pp.38-45
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• 1996

Power steering systems play an important role for the vehicle handling characteristics and driver's steering center feeling during straightforward driving situation. In this paper, the rotary valve, the main component of power steering systems, is modeled and analyzed, and is combined with a 3-DOF(degree of freedom) lateral dynamics model of passenger cars to examine the effects of design parameters on the vehicle steering characteristics. The results can be applied to the development of advanced power steering systems for passenger cars such as electronically-con-trolled power steering system.