scholarly journals Inverse Dispersion for an Unknown Number of Sources: Model Selection and Uncertainty Analysis

2012 ◽  
Vol 2012 ◽  
pp. 1-20 ◽  
Author(s):  
Eugene Yee
Keyword(s):  
Recursive Algorithm ◽  
Atmospheric Dispersion ◽  
Source Model ◽  
Bayesian Probability ◽  
Dispersion Modeling ◽  
Concentration Data ◽  
Measured Concentration ◽  
Inverse Dispersion ◽  
Unknown Number ◽  
Localized Sources

A simple recursive method is presented for performing the inverse dispersion modeling of an unknown number of (localized) sources, given a finite number of noisy concentration data acquired by an array of detectors. Bayesian probability theory is used to address the problem of selecting the source model which is most plausible in view of the given concentration dataset and all the available prior information. The recursive algorithm involves subtracting a predicted concentration signal arising from a source model consisting of N localized sources from the measured concentration data for increasing values of N and examining the resulting residual data to determine if the residuals are consistent with the estimated noise level in the concentration data. The method is illustrated by application to a real concentration dataset obtained from an atmospheric dispersion experiment involving the simultaneous release of a tracer from four sources.

scholarly journals Development of a moving point source model for shipping emission dispersion modeling in EPISODE–CityChem v1.3

2021 ◽  
Vol 14 (7) ◽  
pp. 4509-4534
Author(s):  
Kang Pan ◽  
Mei Qi Lim ◽  
Markus Kraft ◽  
Epaminondas Mastorakos
Keyword(s):  
Fixed Point ◽  
Point Source ◽  
Transport Model ◽  
Atmospheric Dispersion ◽  
Source Model ◽  
Dispersion Modeling ◽  
Emission Sources ◽  
Chemistry Transport Model ◽  
New Model ◽  
Simulation Time

Abstract. This paper demonstrates the development of a moving point source (MPS) model for simulating the atmospheric dispersion of pollutants emitted from ships under movement. The new model is integrated into the chemistry transport model EPISODE–CityChem v1.3. In the new model, ship parameters, especially speed and direction, are included to simulate the instantaneous ship positions and then the emission dispersion at different simulation time. The model was first applied to shipping emission dispersion modeling under simplified conditions, and the instantaneous and hourly averaged emission concentrations predicted by the MPS model and the commonly used line source (LS) and fixed point source (FPS) models were compared. The instantaneous calculations were quite different due to the different ways to treat the moving emission sources by different models. However, for the hourly averaged concentrations, the differences became smaller, especially for a large number of ships. The new model was applied to a real configuration from the seas around Singapore that included hundreds of ships, and their dispersion was simulated over a period of a few hours. The simulated results were compared to measured values at different locations, and it was found that reasonable emission concentrations were predicted by the moving point source model.

scholarly journals Radiation Dose Calculations for a Hypothetical Accident in Xianning Nuclear Power Plant

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Bo Cao ◽  
Junxiao Zheng ◽  
Yixue Chen
Keyword(s):  
Radiation Dose ◽  
Nuclear Power ◽  
Atmospheric Dispersion ◽  
Harmful Effect ◽  
Atmospheric Stability ◽  
Dispersion Modeling ◽  
Dose Calculations ◽  
Air Concentration ◽  
The Public ◽  
Ground Deposition

Atmospheric dispersion modeling and radiation dose calculations have been performed for a hypothetical AP1000 SGTR accident by HotSpot code 3.03. TEDE, the respiratory time-integrated air concentration, and the ground deposition are calculated for various atmospheric stability classes, Pasquill stability categories A–F with site-specific averaged meteorological conditions. The results indicate that the maximum plume centerline ground deposition value of1.2E+2 kBq/m2occurred at about 1.4 km and the maximum TEDE value of1.41E-05 Sv occurred at 1.4 km from the reactor. It is still far below the annual regulatory limits of 1 mSv for the public as set in IAEA Safety Report Series number 115. The released radionuclides might be transported to long distances but will not have any harmful effect on the public.

Inverse AERMOD and SCIPUFF Dispersion Modeling for Farm-Level PM10 Emission Rate Assessment

2021 ◽  
Vol 64 (3) ◽  
pp. 801-817
Author(s):  
Bin Cheng ◽  
Aditya Padavagod Shiv Kumar ◽  
Lingjuan Wang-Li
Keyword(s):  
Wind Speed ◽  
Egg Production ◽  
Single Point ◽  
Dispersion Modeling ◽  
Emission Rates ◽  
Farm Level ◽  
Area Source ◽  
Inverse Dispersion ◽  
Pm10 Emission ◽  
Inverse Dispersion Modeling

HighlightsAERMOD and SCIPUFF were employed to back-calculate farm-level PM10 emission rates based on inverse modeling.Both AERMOD and SCIPUFF did not capture the diurnal and seasonal variations of farm-level PM10 emission rates.AERMOD modeling results were affected by wind speed, with higher wind speed leading to higher emission rates.Higher numbers of receptors and PM10 measurements with greater time resolution may be recommended in the future.Abstract. Air pollutant emissions from animal feeding operations (AFOs) have become a serious concern for public health and ambient air quality. Particulate matter with aerodynamic equivalent diameter less than or equal to 10 µm (PM10) is one of the major air pollutants emitted from AFOs. To assess the impacts of PM10 emissions from AFOs, knowledge about farm-level PM10 emission rates is needed but is challenging to obtain through field measurements. The inverse dispersion modeling approach provides an alternative way to estimate farm-level PM10 emission rates. In this study, two dispersion models, AERMOD and SCIPUFF, were employed to back-calculate farm-level PM10 emission rates based on hourly PM10 concentration measurements at four downwind locations in the vicinity of a commercial egg production farm in the southeast U.S. Onsite meteorological data were simultaneously recorded using a 10 m weather tower to facilitate the dispersion modeling. The modeling results were compared with PM10 emission measurements from two layer houses on the farm. Single-area source, double-area source, and double-volume source were used in AERMOD, while only single-point source was used in SCIPUFF. The inverse modeling results indicated that both SCIPUFF and AERMOD did not capture the diurnal and seasonal variations of the farm-level PM10 emission rates. In addition, the AERMOD modeling results were affected by wind speed, and higher emission rates may be predicted at higher wind speeds. The single-point source for SCIPUFF, the plume rise simplification for AERMOD, and insufficient concentration measurement resolution in response to temporal changes in wind direction may have added uncertainties to the modeling results. The results of this study suggest that more receptors covering more representative downwind locations should be considered in future modeling for farm-level emissions assessment. Moreover, ambient data collection with greater time resolution (e.g., less than one hour) is recommended to capture diurnal and seasonal patterns more rigorously. Only in this way can researchers achieve a better understanding of the effectiveness of inverse dispersion modeling for estimation of pollutant emission rates. Keywords: AERMOD, Animal feeding operations, Egg production, Farm-level emission rate, Inverse dispersion modeling, PM10, SCIPUFF.

Pharmacokinetic Evaluation of a Case of Massive Sotalol Intoxication

1997 ◽  
Vol 31 (7-8) ◽  
pp. 856-859 ◽  
Author(s):  
Carl Gunnar Å Gustavsson ◽  
Ellen Vinge ◽  
Björn O. Norlander ◽  
Emil Pantev
Keyword(s):  
Blood Pressure ◽  
Renal Function ◽  
Elimination Rate ◽  
Normal Range ◽  
Concentration Data ◽  
Measured Concentration ◽  
Temporary Reduction ◽  
Case Summary ◽  
Later Phase ◽  
Elimination Curve

OBJECTIVE: To describe serum concentrations and clearance of sotalol after a massive overdose. CASE SUMMARY: A 37-year-old white man took 11.2 g of sotalol hydrochloride tablets in a suicide attempt. The first serum d,l-sotalol concentration 3 hours after taking the first tablet was 20.6 mg/L and the last measured concentration 59 hours later was 1.8 mg/L. Logarithmic transformation of the concentration data indicated two separate monoexponential phases in the elimination curve, with half-lives of 30.1 and 11.6 hours. DISCUSSION: The shorter serum half-life in the later phase is comparable with that in four previously reported sotalol intoxications and within the normal range. The elimination rate increased in a temporal manner with an increase in systolic blood pressure about 30 hours after the patient was admitted. Since the sotalol elimination rate depends principally on renal function, we believe the initially slow elimination is due to a temporary reduction of the renal function caused by the systolic hypotension. CONCLUSIONS: An initial phase of slow sotalol elimination may occur after severe overdoses. In our patient this was probably due to hypotension. Thus, blood pressure should be monitored carefully.

Estimation of Radiological Consequences at a Proposed Nuclear Power Plant Site Using Atmospheric Dispersion Code

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Kwame Gyamfi ◽  
Sylvester Attakorah Birikorang ◽  
Emmanuel Ampomah-Amoako ◽  
John Justice Fletcher
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Atmospheric Dispersion ◽  
Atmospheric Stability ◽  
Assessment System ◽  
Severe Accident ◽  
Dispersion Modeling ◽  
Stability Class ◽  
Total Effective Dose Equivalent

Abstract Atmospheric dispersion modeling and radiation dose calculation have been performed for a generic 1000 MW water-water energy reactor (VVER-1000) assuming a hypothetical loss of coolant accident (LOCA). Atmospheric dispersion code, International Radiological Assessment System (InterRAS), was employed to estimate the radiological consequences of a severe accident at a proposed nuclear power plant (NPP) site. The total effective dose equivalent (TEDE) and the ground deposition were calculated for various atmospheric stability classes, A to F, with the site-specific averaged meteorological conditions. From the analysis, 3.7×10−1 Sv was estimated as the maximum TEDE corresponding to a downwind distance of 0.1 km within the dominating atmospheric stability class (class A) of the proposed site. The intervention distance for evacuation (50 mSv) and sheltering (10 mSv) were estimated for different stability classes at different distances. The intervention area for evacuation ended at 0.5 km and that for sheltering at 1.5 km. The results from the study show that designated area for public occupancy will not be affected since the estimated doses were below the annual regulatory limits of 1 mSv.

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