• Title/Summary/Keyword: Concentration Model

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Model-Based Simulation Analysis of Wicking Behavior in Hygroscopic Cotton Fabric

  • Hong, Cheol-Jae;Kim, Byung-Jick
    • Journal of Fashion Business
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    • v.20 no.6
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    • pp.66-78
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    • 2016
  • Hygroscopic knitted cotton fabric was found to spontaneously absorb water showing a significantly wide concentration gradient in the absorption direction. A semi-empirical diffusion model was introduced to describe how the wicking behavior compared to the classical capillary model (Washburn's equation), which has been widely used in the textiles industry. The capillary sorption curve and the permeability coefficient, which are key variables for the model equations, were measured using an electronic balance. The concentration profile as a function of the wicking distance and the elapsed time was derived, based on the diffusion model. From the concentration profile, the wicking distance detectable by the human eye or a digital camera with the aid of an image-analysis system, could be described realistically as a function of the time. The classical capillary model could be modified by introducing the tortuous correction factor to match the diffusion model. Wicking models and data-processing techniques in the work could provide useful tools for objectively evaluating the textile's wicking performances.

The Prediction and Evaluation Air Pollutants Concentration around Industrial Complex by using Atmospheric Dispersion Models -Based on ISCST3, FDM, AERMOD- (대기확산모델을 사용한 공단주변지역의 대기오염물질농도 예측 및 평가 -ISCST3, FDM, AERMOD를 중심으로-)

  • 이화운;원경미;배성정
    • Journal of Environmental Science International
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    • v.8 no.4
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    • pp.485-490
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    • 1999
  • We will calculate concentration of air pollutants using ISCST3, FDM and AERMOD of models recommended in U. S. EPA which are able to predict concentration of short term for point source, complex like industrial complex, power plant and burn-up institution. Before executing model, as analyzing computational result of many cases according to selecting of input data, we will increasing predictable ability of model in limit range of model. Especially, we analyzed three cases-case of considering various emission rate according to time scale and not, case considering effect of atmospheric pollution materials removed by physical process. In our study, after comparing and analyzing results of three model, we choose the atmospheric dispersion model reflected well the characteristic of the area. And we will investigate how large the complex pollutant sources such as industrial complex contribute to atmospheric environment and air quality of the surrounding the area as predicting and estimating chosen model.

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Mathematical description of drug distribution in the isolated organ

  • Kim, Chong-Kook
    • Archives of Pharmacal Research
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    • v.3 no.1
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    • pp.13-16
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    • 1980
  • The model of an isolated organ system has been constructed to simulated the behavior of drug in the circulatory system of an acting organ or site. The model is developed on the following assumptions : The drug in the microcirculatory system cannot permeate the capilary walls. The capilary bed is modeled as a simple ideal plug flow system with and without radial concentration gradient. The mathematical model is developed from basic considerations of drug distribution with hemodynamical and pharmacokinetical meanings. It is considered that a nonmetabolic drug substance is injected into the arterial inflow site of an isolated organ at a constant rate. The concentration of the drug in the outflow site is mathematically expressed as a function of time.

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Development of Multiple Transient Storage Model Using Particle Tracking Method (입자추적방법을 이용한 다중저장대모형 개발)

  • Cheong, Tae-Sung;Seo, Il-Won
    • Journal of Korea Water Resources Association
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    • v.37 no.4
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    • pp.257-271
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    • 2004
  • To evaluate behavior in representing solute transport in natural streams, the storage zone model of the axially periodic transient storage zones is developed. The periodic transient storage zone model and continuous storage zone model are verified using the parameters and the tracer concentration vs. time curves observed in laboratory channels. The periodic storage zone model best fit the measured concentration vs. time curves, while the continuous storage model fails to describe some fluctuations and the plateau region of the tail occurring in a discontinuous transient storage system. Dispersion data from Shingobee River, Minnesota, U. S. A. show that the concentration curves simulated by the proposed model fit the observed concentration curves well.

A study on high ozone concentration in Shiwha.Banwol industry complex using photochemical air pollution model- Analysis of meteorological characteristics - (시화.반월단지지역의 고농도 오존일에 대한 광화학모델 적용 연구 - 기상특성에 대한 분석 -)

  • An, Jae-Ho
    • Journal of the Korean Solar Energy Society
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    • v.31 no.5
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    • pp.47-59
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    • 2011
  • The purpose of this paper is to simulate the high ozone concentration in Shiwha Banwol indusrial complex. High pollution episodes (ozone alert) of this area are the results of geographical location and its air pollutants emission. This research has used meteorological model (RAMS) and photochemical air pollution Model (CIT model). As first step of the evaluate of this combined model system simulations are done in terms of meteorological characteristics like wind fields, PBL-height, etc.. Numerical simulations are carried out with real meteorological synoptic data on June. 24-25, 2010. In comparison with real measurement and another research the model reflects well local meteorological phenomena and shows the possibility to be utilized to analyse the pollutant dispersion over irregular terrain region. The high ozone concentration is deeply correlated to the ambient air temperature, wind speed and solar radiation. Local meteorological phenomena like sea-land breeze impact on horizontal dispersion of ozone. This analysis of meteorological characteristics can, in turn, help to predict their influences on air quality and to manage the high ozone episodes.

Model development for chlorine generation using electrolysis (전기분해에 의한 잔류염소 생성 예측 모델 개발)

  • Sohn, Jinsik;Lee, Sunjae;Shin, Chorong
    • Journal of Korean Society of Water and Wastewater
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    • v.23 no.3
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    • pp.331-337
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    • 2009
  • Electrolysis produces hypochlorous acid by using a small quantity of NaCl as electrolyte. This process maximizes the stabilization of drinking water through the control of chlorine residual concentration. This study investigated free chlorine generation by an electrolytic method using $Ti/IrO_2$ and stainless steel. The generation of free chlorine was increased with increasing hydraulic retention time, voltage, chlorine ion concentration and the number of electrodes. However, the change of pH did not affect the generation of free chlorine. There was no significant difference on the behavior of chlorine concentration between electrolytic method and NaOCl injection. In this study, the concentration of free chlorine predicted model based on power functional model was developed various under conditions. Electrolysis free chlorine generation model can be effective tool in the estimation of free chlorine generation.

A method of environmental management using an ecological numerical model in Jindong Bay (진동만에서 생태계모델을 이용한 환경관리기법)

  • 김동선
    • Journal of Environmental Science International
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    • v.12 no.3
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    • pp.345-358
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    • 2003
  • Jindong bay at the northwestern part of Jinhae bay suffers from the occurrence of red tides in summer every year. In order to study the management methods of coastal environments, an ecological numerical model has been developed. The model experiments was forecasted that the load of nutrients from the land and field concentration will be cut down per 10% each. When we cut down 57.2% nitrogen load in the inner bay and 38.4% phosphorous load in the outer bay of bottom layer of the nutrients load from land and field concentration, the seawater quality standard levels up first grade. When we cut down 86.5% nutrients in the inner bay and 93.0% nutrients in the outer bay, the concentration of chlorophyll a decreases below 3.2 $\mu\textrm{g}$/(equation omitted)(an individual concentration of phytoplankton : 10,000cel1/ml), i.e. the red tides do not occur.

Numerical Simulation of Ozone Concentration using the Local Wind Model in Pusan Coastal Area, Korea (부산연안역에서 국지풍모델을 이용한 오존농도의 수치모의)

  • Jeon, Byung-Il;kim, Yoo-Keun;Lee, Hwa-Woon
    • Journal of Environmental Science International
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    • v.6 no.4
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    • pp.335-350
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    • 1997
  • Numerical simulations of photochemical air pollution (CBM: Carbon-Bond Mechanisms under a theoretical three-dimensional local wind system are carried to clarify the fundamental characteristics of the effects of local wind on photochemical air pollution. According to the AWS data of Pusan coastal area and KMA, the surface wind of Pusan during summertime showed a very remarkable land and sea breeze circulation. The ozone concentration distribution using local wind model showed that high ozone concentration zone near coastal area moved toward inland In the afternoon. This change implies a sea breeze Increases the ozone concentration, but a land breeze decreases it in Pusan coastal area.

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Studies on the Effect of Water Quality Parameters on Total Coliform Concentrations in Sewage Effluents (하수방류수의 대장균군 발생에 영향을 미치는 수질인자에 관한 연구)

  • Beck, Young-Seog;Sohn, Jin-Sik
    • Journal of Korean Society on Water Environment
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    • v.22 no.1
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    • pp.166-171
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    • 2006
  • The objectives of the present paper were to investigate the concentration of total coliform in wastewater effluents and the effect of water chemical and physical characters in it. The most correlated parameter with total coliform was COD. It means that the wastewater treatment efficient effects on total coliform concentration. And we developed predictive model for the total coliform concentration. The estimated parameters for model were COD, temperature, nitrite, chloride, Mn and regression model equation was determined; log (Total Coli.) = 1.861+0.065[COD]+0.038[temperature]-0.0004[$Cl^-$]+3.697[Mn]-0.32 [$NO_2-N$] The developed model provided very strong correlation ($R^2:0.82$) between total coliform and regression equation. The parameters having high sensitivity were COD and temperature. So the study indicated that if the temperature and COD of wastewater effluent were known, we would estimate the concentration of total coliform and decide the most effective usage of chlorine.

A Study on the Stress Distribution of Condylar Region and Edentulous Mandible with Implant-Supported Cantilever Fixed Prostheses by using 3-Dimensional Finite Element Method (임플란트 지지 캔틸레버 고정성 보철물 장착시 과두와 하악골의 응력 분포에 관한 3차원 유한요소법적 연구)

  • Kim, Yeon-Soo;Lee, Sung-Bok
    • Journal of Dental Rehabilitation and Applied Science
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    • v.17 no.4
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    • pp.283-305
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    • 2001
  • The purpose of this study was to analyze the stress distribution of condylar regions and edentulous mandible with implant-supported cantilever prostheses on the certain conditions, such as amount of load, location of load, direction of load, fixation or non-fixation on the condylar regions. Three dimensional finite element analysis was used for this study. FEM model was created by using commercial software, ANSYS(Swanson, Inc., U.S.A.). Fixed model which was fixed on the condylar regions was modeled with 74323 elements and 15387 nodes and spring model which was sprung on the condylar regions was modeled with 75020 elements and 15887 nodes. Six Br${\aa}$nemark implants with 3.75 mm diameter and 13 mm length were incorporated in the models. The placement was 4.4 mm from the midline for the first implant; the other two in each quardrant were 6.5 mm apart. The stress distribution on each model through the designed mandible was evaluated under 500N vertical load, 250N horizontal load linguobuccally, buccal 20 degree 250N oblique load and buccal 45 degree 250N oblique load. The load points were at 0 mm, 10 mm, 20 mm along the cantilever prostheses from the center of the distal fixture. The results were as follows; 1. The stress distribution of condylar regions between two models showed conspicuous differences. Fixed model showed conspicuous stress concentration on the condylar regions than spring model under vertical load only. On the other hand, spring model showed conspicuous stress concentration on the condylar regions than fixed model under 250N horizontal load linguobuccally, buccal 20 degree 250N oblique load and buccal 45 degree 250N oblique load. 2. Fixed model showed stress concentration on the posterior and mesial side of working and balancing condylar necks but spring model showed stress concentration on the posterior and mesial side of working condylar neck and the posterior and lateral side of balancing condylar neck under vertical load. 3. Fixed model showed stress concentration on the posterior and lateral side of working condylar neck and the anterior and mesial side of balancing condylar neck but spring model showed stress concentration on the anterior sides of working and balancing condylar necks under horizontal load linguobuccally. 4. Fixed model showed stress concentration on the posterior side of working condylar neck and the posterior and lateral side of balancing condylar neck but spring model showed stress concentration on the anterior side of working condylar neck and the anterior and lateral side of balancing condylar neck under buccal 20 degree oblique load. 5. Fixed model showed stress concentration on the anterior and lateral side of working condylar neck and the posterior and mesial side of balancing condylar neck but spring model showed stress concentration on the anterior side of working condylar neck and the anterior and lateral side of balancing condylar neck under buccal 45 degree oblique load.. 6. The stress distribution of bone around implants between two models revealed difference slightly. In general, magnitude of Von Mises stress was the greatest at the bone around the most distal implant and the progressive decrease more and more mesially. Under vertical load, the stress values were similar between implant neck and superstructure vertically, besides the greatest on the distal side horizontally. 7. Under horizontal load linguobuccally, buccal 20 degree oblique load and buccal 45 degree oblique load, the stress values were the greatest on the implant neck vertically, and great on the labial and lingual sides horizontally. After all, it was considered that spring model was an indispensable condition for the comprehension of the stress distributions of condylar regions.

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