• Title/Summary/Keyword: EMC

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Dehydration Kinetics of Rehmannia (Rehmannia glutinosa Liboschitz)

  • Rhim, Jong-Whan;Kim, Ji-Hye;Jeong, Won-Chul
    • Food Science and Biotechnology
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    • v.16 no.5
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    • pp.771-777
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    • 2007
  • Sliced and whole root of rehmannia were dehydrated in a laboratory dryer at 40, 60, 80, and $100^{\circ}C$ to evaluate the kinetic parameters for dehydration of rehmannia. The drying curves of both samples were characterized by a falling-rate drying period only. Sliced rehmannia dried 1.1 to 3.1 times faster than whole root of rehmannia depending on drying temperature. Equilibrium moisture content (EMC) of rehmannia samples at the drying temperature tested were 0.069-0.078 g water/g dry solid, which was coincided with the monolayer moisture content (0.06 and 0.07 g water/g dry solid) evaluated from desorption isotherms using GAB (Guggenheim-Anderson-de Boer) model. A logarithmic model for thin layer drying was applied to evaluate the drying time to reach EMC ($t_{EMC}$) and drying constant (k). The effect of temperature on $1/t_{EMC}$ and k was described by the Arrhenius model with activation energy values of 32.56 and 47.14 kJ/mol determined using the former parameter, and 34.27 and 38.26 kJ/mol determined using the latter parameter for sliced and whole root of rehmannia, respectively.

Event Mean Concentration of Nitrogen and Phosphorus from a Dairy and Crop Farming Complex Watershed

  • Yoon, Kwang-Sik;Shirmohammadi, Adel;Choi, Woo-Jung;Jung, Jae-Woon
    • Journal of The Korean Society of Agricultural Engineers
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    • v.48 no.7
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    • pp.65-72
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    • 2006
  • Event mean concentration (EMC) of nitrogen (N) and phosphorus (P) is primary information for non-point source pollution assessment of a watershed. The EMCs for various types of agriculture such as dairy and crop farming under different climate and geologic conditions are not fully investigated. A diary- and cropfarming complex agricultural watershed in Piedmont region in Maryland, USA has been monitored for 10 years as a section 319 national monitoring program of US EPA. Dairy manure was the main source of fertilizer for crop farming in this watershed. Observed mean concentrations of N and P for each event were analyzed. Distribution of EMCs for N and P showed a wide range of variations. Representative EMCs of T-N and $NO_{3}-N$ tended to be higher than those reported for other agricultural watersheds. This study confirmed that site-specific EMC information for various agricultural practices is required for better assessment of non-point source pollution using EMC method.

Molecular Diffusion of Water in Paper(III) -Theoretical analysis on vapor sorption properties of fiber surface - (종이내 수분확산 (제3보) -종이 표면의 수증기-흡습성에 관한 이론적 고찰-)

  • Yoon, Sung-Hoon;Jeon, Yang;Park, Jong-Moon
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.31 no.1
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    • pp.61-71
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    • 1999
  • The study aimed at the theoretical analysis of vapor sorption properties of, pp.rmaking fibers. Water vapor affinity and sorption thermodynamic properties of fiber constituents were evaluated based on Henry's law and Hildebrand's solubility theory. Theoretical equilibrium moisture content(ThEMC) on fiber surface was estimated using functional group contribution. Crystallinity of cellulose in fiber significantly controlled the water vapor solubility. Comparisons of the measured equilibrium moisture content data and the estimated ThEMC data coincidently suggested the fact that crystallinity of cellulose in fibers was around 60% to 70%. Carbohydrates constituents including amorphous cellulose and hemicellulose in fibers showed higher vapor solubility than lignin molecules. High correlation existed between ThEMC and vapor solubility as well as between ThEMC and solubility parameter. In the thermodynamic analysis on water-vapor sorption process in fibers, the sorption enthalpy increased as RH increased, whereas sorption entropy and free energy decreased with increasing RH.

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Full Three Dimensional Rheokinetic Modeling of Mold Flow in Thin Package using Modified Parallel Plate Rheometry (개선된 회전형 레올로지 측정법을 이용한 박형 반도체 패키지 내에서의 3차원 몰드 유동현상 연구)

  • LEE Min Woo;YOO Min;YOO HeeYoul
    • Proceedings of the International Microelectronics And Packaging Society Conference
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    • 2003.11a
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    • pp.17-20
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    • 2003
  • The EMC's rheological effects on molding process are evaluated in this study. When considering mold processing for IC packages, the major concerning items in current studies are incomplete fill, severe wire sweeping and paddle shifts etc. To simulate EMC's fast curing rheokinetics with 3D mold flow behavior, one should select appropriate rheometry which characterize each EMC's rheological motion and finding empirical parameters for numerical analysis current studies present the new rheometry with parallel plate rheometry for reactive rheokinetic experiments, the experiment and numerical analysis is done with the commercial higher filler loaded EMC for the case of Thin Quad Plant Packages (TQFP) with package thickness below 1.0 mm. The experimental results and simulation results based on new rheometry matches well in point of the prediction of wire sweep, filling behavior of melt front advancement and void trapping position.

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Probability Distribution of BOD EMC from Paddy Fields (논 유출수 BOD의 유량가중평균농도(EMC) 확률분포)

  • Jin, So-Hyun;Jung, Jae-Woon;Yoon, Kwang-Sik;Choi, Woo-Jung;Choi, Dong-Ho;Kim, Sang-Don;Kang, Jae-Hong;Choi, Yu-Jin
    • Journal of Environmental Science International
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    • v.19 no.9
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    • pp.1153-1159
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    • 2010
  • Identification of probability distribution for water quality constituents from specific land use is important to achieve successful implementation of TMDL program. In this 3-year study, distribution of discharge and BOD(Biological Oxygen Demand) concentration from paddy rice fields were monitored. Four probability distributions, normal, log-normal, Gamma and Weibull were fitted and the goodness-of-fit was assessed using probability plots and Kolmogorov-Smirnov test. $EMC_s$ of BOD in runoff from paddy field ranged 0.37 to $7.99\;mgL^{-1}$, and all four probability distributions were acceptable. But the normal distribution would be preferred for BOD from paddy fields considering nature of straight forward application.

A Study on the Sensor for Measuring the High Frequency Magnetic Fields (고주파자계측정용 센서에 관한 연구)

  • Lee, Bok-Hee;Jeong, Seung-Soo;Park, Hyung-Ki;Paek, Yong-Hyun;Yim, Dong-Mook
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1992.11a
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    • pp.114-117
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    • 1992
  • This paper presents the design and calibration methods of self-integrated magnetic sensor. Also the distance response measurement of magnetic field produced a transient large current and the frequency response measurement are carried out As the integrating resistance increases. the sensitivity of the sensor is improved, but the decay time constant of response decreases, Also the experimental results are well agreed with the theoretical analysis of the equivalent circuit.

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EMC Analysis between the COMS RS and the GEO Launch Vehicles RE (통신해양기상위성 복사감응과 정지궤도 발사체 복사방출에 대한 EMC 해석)

  • Kim, Eui-Chan;Han, Cho-Young;Lee, Ho-Hyung
    • Aerospace Engineering and Technology
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    • v.8 no.2
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    • pp.33-40
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    • 2009
  • In this paper, the preliminary EMC analysis process between the Communication, Ocean and Meteorological Satellite (COMS) and Geostationary Earth Orbit (GEO) launch vehicles in the frequency range [1MHz-47MHz] is described. The launch vehicle Radiated Emission (RE) specifications have been compared to COMS satellite Radiated Susceptibility (RS) limits. The COMS RS limits are the RS qualification levels of COMS units during launch. The negative margins appear between land launch or soyuz launch vehicle RE and COMS RS. Then, if the land launch or soyuz is chosen by the customer, The tests should be performed at satellite level in order to demonstrate the compatibility with respect to launch vehicles specifications.

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Determination of Event Mean Concentrations and Pollutant Loadings in Highway Storm Runoff (고속도로 강우 유출수내 오염물질의 EMC 및 부하량 원단위 산정)

  • Kim, Lee-Hyung;Kang, Joohyon
    • Journal of Korean Society on Water Environment
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    • v.20 no.6
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    • pp.631-640
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    • 2004
  • This research was conducted to understand the magnitude and nature of the stormwater emissions with the goal of quantifying stormwater pollutant concentrations and mass emission rates of pollutants. Eight highway sites in Southern California area were monitored for three years with collecting of grab and flow-weighted composite samples, rainfall and runoff flow. Generally the EMCs cannot be determined by simple statistical averaging of measured pollutant concentrations because of random characteristics of runoff quality and quantity. Therefore, this manuscripts will show a new EMC determination method. The EMC ranges of 95% confidence intervals are 102.78-216.37mg/L for TSS, 104.53-251.79mg/L for COD, 5.42-10.58mg/L for oil & grease and 2.42-10.18mg/L for TKN. The ranges of washed-off mass loading are determined to $0.06g/m^2-17.27g/m^2$ for TSS and $0.1-3.23g/m^2$for COD.

Epithelial-Myoepithelial Carcinoma of the Parotid Gland - Report of a Case Misinterpreted as Pleomorphic Adenoma on Fine Needle Aspiration Cytology - (이하선의 상피-근상피암종 - 세침흡인 세포검사에서 다형성선종으로 오진된 1 예 보고 -)

  • Kim, Dong-Chul;Lee, Kyo-Young;Kang, Cang-Suk;Shim, Sang-In;Lee, Ah-Won
    • The Korean Journal of Cytopathology
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    • v.13 no.1
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    • pp.42-46
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    • 2002
  • Epithelial-myoepithelial carcinoma(EMC) is a rare, low grade malignant tumor of the salivary glands. The EMC has a distinctive histological appearance comprising ductal structures with an inner epithelial cell component and an outer layer of myoepithelial cells which show plump clear cytoplasm. The cytologic features of the EMC have been rarely described. A correct cytological diagnosis to this rare tumor is difficult with high false negative rate. We report a case of EMC in which fine needle aspiration cytologic findings were misinterpreted as a pleomorphic adenoma.

Study on the Preparation of the Phosphoric Flame retardent for the EMC (EMC용 반응형 인계 난연 수지 개발)

  • Ahn, Tae-Kwang;Kim, Han-Byung;Ryu, Kum-Sook
    • Proceedings of the KAIS Fall Conference
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    • 2009.05a
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    • pp.372-375
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    • 2009
  • 반도체 봉지재란 실리콘 칩, 골드와이어, 리드프레임 등의 반도체 소지를 열, 수분, 충격으로부터 보호하기 위해 밀봉하는 재료로서 EMC(Epoxy Moding Compound)가 가장 많이 쓰인다. EMC는 기계적, 전기적 성능향상을 위한 무기재료로 실리카(Silica), 열에 의해 경화되어 3차원 경화구조를 형성하는 에폭시수지, 빠른 경화특성을 부여하기 위한 경화제로서의 페놀수지, 유기재료와 무기재료 사이의 결합력을 높이기 위해 커플링제, 카본블랙, 이형성 확보를 위한 왁스(Wax), 착색제(Colorant), 난연제(Flame Retardant)등의 첨가제로 구성되는 복합소재로써 본 연구에서는 에폭시의 유형에 따른 용융 실리카를 주충진재로 하여 각각의 봉지재의 첨가제를 기준으로 할 때 다양한 형태의 친환경 비할로겐계 반응형 난연제를 합성하는 기술을 개발하고 비 할로겐계 및 Sb 계 첨가형 난연제의 혼용 배합을 통해 친환경 EMC용 난연제의 제조기술을 개발하였다. 이들 EMC의 요구특성은 요구특성은 외부환경으로부터 칩 보호, 칩을 전기적으로 절연특성 유지, 칩의 작동시 발생되는 열의 효과적인 방출 특성 유지, 실장(Board Mounting)의 간편성 특성을 확보해야 하는 특성을 지니고 있어 이들 요구특성에 적합한 특성조사가 함께 이루어졌다.

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