• Title/Summary/Keyword: Mass Balance

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Optimal Location Issue on both Supporting Bearing and Unbalance Mass of the Balance Shaft Module in a Inline 4-Cylinder Engine (직렬 4기통 엔진용 밸런스 샤프트 모듈의 불평형 질량 및 베어링 위치 선정)

  • Lee, Dong-Won;Kim, Chan-Jung;Bae, Chul-Yong;Lee, Bong-Hyun
    • Transactions of the Korean Society of Automotive Engineers
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    • v.18 no.4
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    • pp.1-7
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    • 2010
  • Large quantity of bending deformation as well as irregular rotating torque fluctuation are the main struggles of the balance shaft module during a high speed rotation. Since two issues are much sensitive to the location of both supporting bearing and unbalance mass at a balance shaft, it is recommended to construct a design strategy on balance shaft at the early stage so as to save developing time and effort before approaches to the detailed design process. In this paper, an optimal design formulation is proposed to minimize the elastic strain energy due to bending as well as the kinematic energy of polar moment of inertia in rotation. Case studies of optimal design are conducted for different mass ratio as well as linear combination of objective function and its consequence reveals that global optimum of balance shaft model is existed over possible design conditions. Simulation shows that best locations of both supporting bearing and unbalance are globally 20% and 80%, respectively, over total length of a balance shaft.

Mass-estimation Algorithm by Vibration Response Measurement of Dynamic Balance (동적 저울의 진동응답 측정에 의한 질량 추정 알고리즘)

  • 김병삼
    • The Journal of the Acoustical Society of Korea
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    • v.19 no.5
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    • pp.71-78
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    • 2000
  • Quickness and precision are the two most important requirements for an industrial scale used in production lines. In this paper, a new approach, "Mass-estimation algorithm by vibration-response measurement of dynamic balance", is presented to improve some of drawbacks in conventional scales. The system, consisted of velocity and displacement sensors, spring scale, analog-digital converter and microcomputer, is based on full utilization of dynamic mass measurement of velocity and displacement via microcomputer-assisted real time monitoring. The resulting system, when combined with appropriate mass estimation algorithm software, has shown its effectiveness in terms of two desirable characteristics required.

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The Estimation of N, P mass Balance in Masan Bay using a Material Cycle Model (물질순환 모델을 이용한 마산만의 질소, 인 수지 산정)

  • 김동명;박청길;김종구
    • Journal of Environmental Science International
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    • v.7 no.6
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    • pp.833-843
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    • 1998
  • It is noted that the red tides and the oxygen-deficient water mass are extensively developed in Masan Bay during summer. The nutrients mass balance was calculated in Masan Bay, using the three-dimensional numerical hydrodynamic model and the material cycle model. The material cycle model was calibrated with the data obtained on the field of the study area in June 1993. The nutrients mass balance calculated by the combination of the residual currents and material cycle model results showed nutrients of surface and middle levels to be transported from the inner part to the outer part of Masan Bay, and nutrients of bottom level to be transported from outer part to inner part of Masan Bay. The uptake rate of DIN in the box A1(surface level of inner part) was found to be 337. 5mg/$m^3$ㆍday, the largest value in all 9 boxes and that of DIP was found to be 18.6mg/$m^3$ㆍday in box A1, and the regeneration rate of DIN was found to be 78.2mg/$m^3$ㆍday in the box A3(bottom level of inner part), and that of DIP was found to be 18.6mg/$m^3$ㆍday in box A1. The regenerations of DIN and DIP in the water column of the entire Bay were found to be 7.66ton/day and 760kg/day, respectively. And the releases of DIN and DIP from the sediments of the entire Bay were found to be 2.86ton/day and 634kg/day, respectively. The regeneration rate was 2.5 times as high as the release rate in DIN, and 1.2 times in DIP. The results of mass balance calculation showed not only the nutrients released from the sediments but the nutrients regenerated in water column to be important in the control and management of water quality in Masan Bay.

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Design and Fabrication of a Mass-spring System for the Force-balance Servo Accelerometer (힘평형 서보 가속도계의 질량지지 장치 설계 및 제작)

  • Kim, Young-Dam;Go, Young-Jun;Nam, Hyo-Duk;Lee, Doo-Hee;Chang, Ho-Gyeong
    • The Journal of the Acoustical Society of Korea
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    • v.20 no.5
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    • pp.14-20
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    • 2001
  • The mass-spring system with four arms for the force-balance servo accelerometer was designed and fabricated. The response characteristics of a mass-spring system was calculated with the change of arms thickness and seismic mass by the finite element method (FEM). Furthermore, the response characteristics of accelerometer was measured using the change of interference pattern and response voltage value by Michelson interferometer. The response characteristics with changing length and thickness of arm was changed drastically, and changing seismic mass was minor effect for the response characteristics of mass-spring system. The measured resonant frequencies have good agreement with that of numerical analysis within 5% range.

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Estimation of Source Contribution for PM10 by Chemical Mass Balance(CMB) in Busan

  • Jeon, Byung-Il;Lee, Young-Mi
    • Journal of Environmental Science International
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    • v.17 no.4
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    • pp.359-364
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    • 2008
  • PM10 samples were collected from July 2007 to Oct. 2007 at Gwaebopdong(inland area) and Dongsamdong(coastal area), in Busan. This paper investigates the contribution of emission sources to PM10 mass in Busan. Source apportionment results derived from the chemical mass balance(CMB) method. A source profiles applied in this study is organized to minimize the collinearity among sources type via statistical method. Source profiles applied in this study utilized a measured value of fine particle directly sampled from metropolitan area such as Seoul and Incheon, After a CMB modeling, sulfate and nitrate related sources among those contributing to PM10 in Busan showed high contribution by 36.53% in Gwaebopdong and 42.02% in Dongsamdong.

Estimation of Environmental Characteristics for Deep Ocean Water Development Site Using Ecological Model (생태모델을 이용한 해상형 해양심층수 사업해역의 환경 특성 평가)

  • Kim, Dong-Myung
    • Journal of Environmental Science International
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    • v.20 no.7
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    • pp.919-927
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    • 2011
  • A ecosystem model was applied for understanding of circulation process of state variables in marine ecosystem. A mass balance was conducted by calculating the physical process. The sensitivity analysis was conducted to know which coefficient is the most effective factor to the state variables in the model. The results of the mass balance indicate that the primary production was 58.6 ton C/day in the case of mass flux. DIN and DIP in nutrient ingestion of phytoplankton were each 7.9 ton N/day, 1.1 ton P/day. POC and DOC in mineralization of organic matter were each 10.8 ton C/day, 40.6 ton C/day. The results of sensitivity analysis showed that the maximum growth rate of phytoplankton was the most important factor for overall state variables. In the case of nutrients, Half saturation constant of DIN, and mineralization rate of DOM for COD were important factor.

A Numerical Study on the Design of Exchanger for Desiccant Dehumidifier (데시칸트 제습기용 열교환기 설계에 관한 수치해석적 연구)

  • Kim, Chi-Wan;Ahn, Young-Chull;Kim, Gil-Tae
    • Journal of Power System Engineering
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    • v.17 no.6
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    • pp.54-62
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    • 2013
  • A numerical analysis is performed to evaluate mass flow balance in the heat exchanger for the dehumidifier. To improve the mass flow balance for maximum heat transfer performance, inlet, outlet and baffle are changed. Mass flow balance is evaluated by non-uniformity of flow which is the same concept with the standard deviation. Usually, there will occur many paths between the inlet and the outlet, however, it will follow shortest and low resistance ways. The uniform distribution of flow is numerically analyzed for several types of heat exchangers. Making the shortest way between the inlet and the outlet is most important factor. Two types of heat exchangers are installed in the dehumidifier and 4 cases of Type A heat exchangers and 3 cases of Type B heat exchangers are evaluated and optimized. The result of this research is applied to design heat exchanger for commercial dehumidifiers.

Mass balance of the phosphorus and nitrogen in variable input concentration and fertilization in cropping rice (수도재배에서 유입수의 농도와 시비량의 변화에 의한 질소, 인의 Mass Balance(지역환경 \circled3))

  • 황하선;윤춘경
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2000.10a
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    • pp.623-628
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    • 2000
  • This study were conducted to evaluate the mass balance of phosphorus and nitrogen with cropping in experimental pot where the mass of input concentration, and fertilization were variable. Four treatments include CSWNF, TWCF, SWNF. And these cases were compared to the control case of tap water irrigation with conventional fertilization (CONTROL). Fertilization were following conventional fertilization , N : P : K = 11kg : 7kg : 8kg. Input water loading was CSWNF (N:48.7g ,P:3.6g), TWCF(7.8g, 0.6g), SWHF(38.8g ,2.9g), TWNF(38.8g, 2.9g ) and CONTROL(0g ,0g) The result is nitrogen decrease rate; TWCF(19.2%), SWHF(14.9%), CSWNF(9.2%) and SWCF(5.6%). phosphorous decrease rate ; TWCF (10%), SWHF(3.7%), SWCF(0.9%) and CSWNF(0.3%).

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