Experimental Study of Gas Dispersion over Complex Terrain

2016 ◽  
Vol 821 ◽  
pp. 85-90 ◽  
Author(s):  
Petr Michálek ◽  
David Zacho
Keyword(s):  
Experimental Study ◽  
Complex Terrain ◽  
Dispersion Model ◽  
Concentration Field ◽  
Ground Level ◽  
Gas Emission ◽  
Gas Dispersion ◽  
Terrain Model ◽  
Flame Ionization ◽  
Ionization Detectors

Experimental study of gas dispersion over complex terrain model was performed in VZLU Prague. A complex terrain model was mounted into a boundary layer wind tunnel and equipped with ground-level gas emission source. Concentration field of the emitted gas was measured using comb suction probe and flame ionization detectors. The results will serve for verification and validation of a new computational dispersion model.

scholarly journals Development of a Line Source Dispersion Model for Gaseous Pollutants by Incorporating Wind Shear near the Ground under Stable Atmospheric Conditions

2020 ◽  
Vol 4 (1) ◽  
pp. 17
Author(s):  
Saisantosh Vamshi Harsha Madiraju ◽  
Ashok Kumar
Keyword(s):  
Air Pollution ◽  
Urban Areas ◽  
Wind Shear ◽  
Dispersion Model ◽  
Near Field ◽  
Ground Level ◽  
Gaseous Pollutants ◽  
Air Pollution Control ◽  
Mobile Sources ◽  
Input Variables

Transportation sources are a major contributor to air pollution in urban areas. The role of air quality modeling is vital in the formulation of air pollution control and management strategies. Many models have appeared in the literature to estimate near-field ground level concentrations from mobile sources moving on a highway. However, current models do not account explicitly for the effect of wind shear (magnitude) near the ground while computing the ground level concentrations near highways from mobile sources. This study presents an analytical model based on the solution of the convective-diffusion equation by incorporating the wind shear near the ground for gaseous pollutants. The model input includes emission rate, wind speed, wind direction, turbulence, and terrain features. The dispersion coefficients are based on the near field parameterization. The sensitivity of the model to compute ground level concentrations for different inputs is presented for three different downwind distances. In general, the model shows Type III sensitivity (i.e., the errors in the input will show a corresponding change in the computed ground level concentrations) for most of the input variables. However, the model equations should be re-examined for three input variables (wind velocity at the reference height and two variables related to the vertical spread of the plume) to make sure that that the model is valid for computing ground level concentrations.

scholarly journals Dense gas dispersion model development and testing for the Jack Rabbit II phase 1 chlorine release experiments

2018 ◽  
Vol 192 ◽  
pp. 218-240 ◽  
Author(s):  
Simon Gant ◽  
Jeffrey Weil ◽  
Luca Delle Monache ◽  
Bryan McKenna ◽  
Maria M. Garcia ◽  
...  
Keyword(s):  
Dispersion Model ◽  
Phase 1 ◽  
Model Development ◽  
Dense Gas ◽  
Gas Dispersion

SYMPOSIUM ON URINARY CONSTITUENTS OF LOW MOLECULAR WEIGHT Session III

1968 ◽  
Vol 14 (6) ◽  
pp. 491-512 ◽  
Author(s):  
Ian E Bush
Keyword(s):  
Biochemical Analysis ◽  
General System ◽  
Low Molecular Weight ◽  
Gas Liquid Chromatography ◽  
Double Blind ◽  
Flame Ionization ◽  
Routine Work ◽  
Central Apparatus ◽  
Ionization Detectors ◽  
Blind Trials

Abstract A summary of the strategy and progress in devising a general system of biochemical analysis based on the direct photometry, or "scanning" of thin-media chromatograms is presented. Recent results suggest that the method is as precise and as accurate as other types of quantitative chromatography. It is capable of reasonably easy adoption by workers previously unfamiliar with the basic technic and apparatus. It has been subjected to more rigorous quality control by blind and double-blind trials concurrent with ordinary routine work than is usual, and has passed these tests adequately. Data processing by a small, relatively inexpensive digital computer is capable of handling the data produced by the central apparatus of the method. The sensitivity of newer instruments using well-established fluorescence reactions compares very favorably with that of flame-ionization detectors in gas-liquid chromatography but not with the electron-capture detector as yet.

scholarly journals CFD Analysis of Indoor Chlorine Gas Dispersion Storage: Temperatures, Wind Velocities and Ventilation Effects Studies

2016 ◽  
Vol 16 (1) ◽  
pp. 1
Author(s):  
M. Safakar ◽  
S. Syafiie ◽  
R. Yunus
Keyword(s):  
Ground Level ◽  
Dense Gas ◽  
Human Beings ◽  
Potential Health ◽  
Gas Dispersion ◽  
Indoor Space ◽  
Hazardous Chemical ◽  
Chlorine Gas ◽  
Different Temperatures ◽  
Wind Velocities

The Chemical products factories encounter inherent environmental risks in the process. The indoor release of hazardous chemical gases that are heavier than the air is nowadays a special subject for scrutiny because the dense clouds of the gas have a tendency to insist on the ground level or near the human breath level, causing fatal injuries or other potential health threats to human beings. In this study, a computational fluid dynamics (CFD) code FLUENT was employed in order to model the accidental indoor dispersion of a dense gas (chlorine) from a small undetected leak in an indoor industrial environment. Furthermore, the effects of different temperatures, wind velocities and ventilation on diffusion of chlorine are investigated in this paper. Results of the simulations represented that the chlorine gas dispersion would behave like the liquid and currents on the floor. It was also found that the chlorine concentration above the ground level increased slowly. Showing the effects of various temperatures and wind on spreading the dense gas will help to better identify the potential risks. In this research, the effects of the environmental situations with the release and spread of chlorine in the indoor space were meticulously investigated.

A Pure Rubidium/Quartz Source for Alkali Flame Ionization Detectors

1978 ◽  
Vol 16 (1) ◽  
pp. 8-11 ◽  
Author(s):  
R. Greenhalgh ◽  
J. Muller ◽  
W. A. Aue
Keyword(s):  
Flame Ionization ◽  
Ionization Detectors

scholarly journals Seasonal and Circadian Rhythm of a 1,8-Cineole Chemotype Essential Oil of Calycolpus goetheanus From Marajó Island, Brazilian Amazon

2020 ◽  
Vol 15 (6) ◽  
pp. 1934578X2093305
Author(s):  
Edimara L. dos Santos ◽  
Ananda M. Lima ◽  
Vilmara Fabrícia dos S. Moura ◽  
William N. Setzer ◽  
Joyce Kelly R. da Silva ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Chemical Composition ◽  
Rainy Season ◽  
Brazilian Amazon ◽  
Dry Season ◽  
Chemical Compositions ◽  
Flame Ionization ◽  
Group I ◽  
Marajó Island ◽  
Ionization Detectors

Chemical composition of essential oils (EOs) of Calycolpus genus have been reported in the literature. However, there is only 1 report about volatile profile from Calycolpus goetheanus. This work aims to evaluate the seasonal and circadian influences on EO composition and yield of C. goetheanus collected in Marajó Island, Brazilian Amazon. For the circadian study, the leaves were collected in January (rainy season) and July (dry season) every 3 hours during a period of 15 hours. The EOs were obtained by hydrodistillation and their chemical compositions analyzed by gas chromatography coupled to mass spectrometry and flame ionization detectors. The major compound identified in all EO samples was 1,8-cineole with amounts ranged from 14.4% (January, 6 am) to 33.0% (July, 3 pm). The highest average of 1,8-cineole was obtained during circadian study of the dry season (25.5% ± 5.8%) and the lowest during the circadian study of the rainy season (15.6% ± 1.5%). The multivariate analysis grouped the samples into 2 different groups: Group I characterized by the lowest amounts of 1,8-cineole (16.0%-18.7%), and Group II characterized by a higher content of 1,8-cineole (24.0%-33.0%). The oil yield and chemical composition did not show relationship with climate parameters (solar radiation, humidity, and temperature). Therefore, there was only quantitative variability in the EOs compositions during the circadian rhythm evaluated on dry and rainy seasons.

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