• Title/Summary/Keyword: Mass changes

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The experimental study of the performance characteristics of a tumbler type laundry dryer (통기드럼형 의류용 건조기의 성능특성에 관한 실험적 연구)

  • Jang, Yong-Soo;Lee, Sang-Won;Kim, Soo-Yeon;Jung, Pyung-Suk
    • Proceedings of the KSME Conference
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    • 2000.04b
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    • pp.187-192
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    • 2000
  • The textile which is rotated in the tumbler dryer is dried by the heated air. the energy consumption for drying textile depends on various parameters. The objective of this study is to save the energy and the drying time. One of the various methods for energy saving is EGR(exhaust gas recirculation). We set the drying equipment for this study and perform the experimental study with the changes of the recirculation rate, the input power, and the air mass flow rate. We found the optimal drying conditions.

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Dynamic Simulation of Engine Torque for Hardware-in-the-loop Simulation (엔진 토크의 동적 시뮬레이션에 관한 연구)

  • 조한승;송해박;이종화;고상근
    • Transactions of the Korean Society of Automotive Engineers
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    • v.5 no.2
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    • pp.94-110
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    • 1997
  • In the present study, a mean torque predictive model has been proposed and experimentally validated. It includes induction air mass model, fuel delivery model and mean production mode. Air induction and fuel delivery model considering dynamic behaviors of air induction and fuel delivery were proposed to predict the air-fuel ratio excursions under transient condition. Torque function model reflects thermal efficiency, volumetric efficiency, friction and effect of spark timing. In the spark timing model, knock limit and acceleration retard are included. Experiments were carried out to validate the simulation model for the step changes of throttle at constant engine speed. The results show reasonable agreements between simulation and experiment at fully warmed condition. Using this model, fueling strategies are varied with fast throttle open and it can predict air-fuel ratio excursion and IMEP.

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A Sensitivity Analysis of Centrifugal Compressors Empirical Models

  • Baek, Je-Hyun;Sungho Yoon
    • Journal of Mechanical Science and Technology
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    • v.15 no.9
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    • pp.1292-1301
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    • 2001
  • The mean-line method using empirical models is the most practical method of predicting off-design performance. To gain insight into the empirical models, the influence of empirical models on the performance prediction results is investigated. We found that, in the two-zone model, the secondary flow mass fraction has a considerable effect at high mass flow-rates on the performance prediction curves. In the TEIS model, the first element changes the slope of the performance curves as well as the stable operating range. The second element makes the performance curves move up and down as it increases or decreases. It is also discovered that the slip factor affects pressure ratio, but it has little effect on efficiency. Finally, this study reveals that the skin friction coefficient has significant effect on both the pressure ratio curve and the efficiency curve. These results show the limitations of the present empirical models, and more resonable empirical models are reeded.

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An Experimental Study of the Improvement of Driveability in Vehicle Acceleration Mode (차량 급가속시 운전성 개선을 위한 실험적 연구)

  • 송해박;최윤준;이종화;조한승;조남효
    • Transactions of the Korean Society of Automotive Engineers
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    • v.9 no.6
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    • pp.65-75
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    • 2001
  • Modern vehicles require a high degree of refinement including good driveability. Vehicle driveability, which becomes a key decisive factor f3r marketability, is affected by many parameters such as engine control and the dynamic characteristics in drive lines. Therefore engine and drive train characteristics should be considered to achieve a well balanced vehicle response simultaneously. This paper describes experimental procedures which have been developed to measure engine torque and investigate shuffle characteristics. To analyze the vehicle dynamic behavior, fractional torques and inertia mass moment of engine, and drive train were measured. Shuffle characteristics during tip-in condition were investigated in an experimental vehicle at 2nd and 3rd gear stages. It was found that the shuffle characteristics were caused by sudden changes of engine torque and have a different vibration frequency with gear stage variation. Inertia mass moment of engine including flywheel rotation showed a key factor for the shuffle characteristics.

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Forced Vibration Analysis of a Hollow Crankshaft by using Transfer Matrix Method and Finite Element Method (전달 행렬법과 유한요소법을 이용한 중공 크랭크축의 강제 진동 해석)

  • 김관주;최진욱
    • Transactions of the Korean Society of Automotive Engineers
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    • v.5 no.6
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    • pp.44-52
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    • 1997
  • As part of the effort to reduce the weight of powertrain, a hollow crankshaft has been designed. The mass reduction of the crankshaft changes the dynamic properties of the crankshaft such as moment of inertia, and torsional, bending stiffness. The purpose of this paper is to compare the dynamic behavior of the hollow crankshaft with that of the original, solid crankshaft. Global dynamic behavior of the crankshaft is analyzed bgy the transfer matrix method(TMM). The crankshaft has been modeled by 38 lumped mass and stiffness elements. The dynamic patameters of each lumped element are provided by Finite Element Method(FEM). The responses of the crankshaft from TMM are fed back as loading conditions to the Finite Element model to obtain dynamic stresses for critical areas of the crankshaft.

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The Effect of Loading Conditions on Ship Vibration Characteristics (선박(船舶)의 적화상태(積貨狀態)가 선체진동(船體振動) 특성(特性)에 미치는 영향)

  • K.C.,Kim;M.K.,Kwak;H.M.,Kim
    • Bulletin of the Society of Naval Architects of Korea
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    • v.20 no.1
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    • pp.29-33
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    • 1983
  • The loading condition, of a ship, especially a multi-purpose cargo carrier, in service, is often changed. Then, the prediction of natural frequency changes is necessary to provide measures for prevention of ship vibrations. In this paper a simplified method for the above purpose is presented. The bases of the method are analytical solutions for the lateral vibrations of uniform Timoshenko beams carrying a concentrated mass and the Dunkerley's formula. In this method a ship in the standard ballast condition is reduced to a uniform Timoshenko beam having same system parameters as those of the midship section. To investigate the validity of the proposed method, numerical calculations are carried out for a 46,000 DWT bulk carrier and compared with detailed calculations based on the finite difference method. Even in cases those the cargoes in a hold, length of which is about 13% of the ship's length, are reduced to a concentrated mass, the proposed method gives results of several percent differences from the detailed calculations up to the six-noded mode.

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Variation of Fat and Protein Reserves in Wintering Dunlin, Calidris alpina (월동기 민물도요 Calidris alpina 의 지방과 단백질의 변화)

  • 권기정;황규황
    • Journal of Environmental Science International
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    • v.1 no.1
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    • pp.23-27
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    • 1992
  • The changes of pectoral muscle size (as an index of protein reserves) and fat reserves (as an index of lipid) were measured in wintering Dunlin during 1988 -1989 on two estuaries located in the south coast of Korea. The mean of lean mass of February population was greater(11.8%) than that of October population. SMI of October population was greater(4.5%) than that of February population and lipid index of October population also greater(1.6%) than that of February population. This show that the body condition of October population is better than February population. The mean of fat and protein reserves of 22 % of Dunlin arriving on October for their wintering were higher than that of others, this group seems to continue their migration to south further and 11% of the wintering population seems to starve during winter.

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Characteristics of Reduced Metal from Spent Oxide Fuel by Lithium

  • Kim Ik-Soo;Seo Chung-Seok;Shin Hee-Sung;Hwang Yong-Soo;Park Seong-Won
    • Nuclear Engineering and Technology
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    • v.35 no.4
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    • pp.309-317
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    • 2003
  • The mass balance of the unit processes of the Advanced spent fuel Conditioning Process was calculated to obtain basic information. Based on this mass balance, the changes in decay heat and radioactivity of the spent fuel due to the metallization in the high temperature molten salt system were estimated. The decay heat and the radioactivity were calculated by using the ORIGEN2 computer code, and the result showed that the decay heat and the radioactivity of the metallized spent fuel ingot were $24.27\%\;and\;24.24\%$, respectively, compared to those of oxide spent fuel.

Venereal Squamous Papilloma in a Male Dog

  • Yun, Sungho;Kwon, Young-sam
    • Journal of Veterinary Clinics
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    • v.33 no.2
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    • pp.122-123
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    • 2016
  • A dog (Maltese, 4-year-old, intact male) was referred to the hospital because of the multiple cabbage-shaped nodular masses on penis, preputial fornix and inner layer of prepuce with the free-roaming history. Those appearance was similar with the characteristic of transmissible venereal tumor (TVT). As a result, it was tentatively diagnosed as TVT by the veterinarian of a local clinic and treated with vincristine sulfate. However, the lesion did not regress. Histologically, the mass was consisted of fibrovascular connective tissue stalks and keratinized stratified squamous epithelium, and koilocytosis and intranuclear inclusion body were not shown in the epithelial layer. In addition, inflammatory changes were minimal in the tissue of mass. Based on these findings, this case was diagnosed as venereal squamous papilloma. As the treatments of TVT and papilloma differs, practitioners must be cautious with the diagnosis.

Metabolomic approach for evaluating drug response

  • Jung, Byung-Hwa
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 2007.11a
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    • pp.11-15
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    • 2007
  • Metabolomics is an emerging technology which makes it possible to evaluate change of biological system in response to the physiological, environmental alterations. It has advantages in the simplicity and sensitivity to analyze metabolites since the researcher can use cutting edge instrument, such as mass spectrometry and simple sample preparation method compared to genomics or proteomics. Nowadays this technology has been tried in pharmaceutical area to investigate toxicity and efficacy of drug candidates and drugs in preclinical test. The metabolomic applications on the pharmaceutics for early prediction on toxicity and efficacy are described in this presentation. The multivariate analysis to get metabolic fingerprinting and its relations with the physiological changes are investigated with several drugs. Feasibility of metabolomic application for pharmaceutical area would be suggested from those researches.

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