Khaled Sadek Mohamed Essa
@eaea.org.eg
Mathematics and Theoretical Physics
Egyptian Atomic Energy Authority
RESEARCH INTERESTS
Atmospheric Research
Scopus Publications
Scopus Publications
Khaled S. M. Essa, Sawsan I. M. El Saied, A. A. Wheida, and Mostafa El-Nazer
University of Baghdad College of Science
This study investigates instantaneous and continuous sources as point, line, and area sources. Gaussian concentration in the case of the puff model with an instantaneous point source inhomogeneous longitudinal diffusion is investigated. The concentration is calculated using different dispersion parameters to get the proposed normalized concentration of the puff model at ground level around the centerline, which is compared with observed data by the Copenhagen experiment and previous work [1]. Also, the continuous point source is used to get the Gaussian plume model in three dimensions using dispersion parameters to compare with the observed concentration data measured by the Egyptian Atomic Energy Authority for Iodine-135 (I135) in an unstable condition.
KHALED S. M. ESSA, SOAD M. ETMAN, MAHA S. EL-OTAIFY, and M. EMBABY
India Meteorological Department
The mathematical formulation of the concentration of the diffusing particles in air was derived by solving analytically the advection-diffusion equation taking into consideration: (1) the vertical variation of wind speed and eddy diffusivity with height above ground. (2) the vertical diffusion is limited by an elevated impenetrable inversion layer located at the top of the atmospheric boundary layer (ABL) of height h. (3) the dry deposition of the diffusing particles at the ground surface which was included through the boundary conditions. A power law profile is used to describe the vertical variation of eddy diffusivity with height, while the sum of power law profile and logarithmic law is used to describe the vertical variation of wind speed with height above ground surface. The decay distance of a pollutant along the wind direction was derived. The present solution was evaluated against the dataset from Hanford diffusion experiment in stable conditions. The results are discussed and presented in illustrative figures.
Khaled S. M. Essa and Hanaa Mohamed Ahmed Taha
Springer Science and Business Media LLC
AbstractIn this article, two proposed analytical model solutions of the steady-state advection-diffusion equation were carried out using the technique of advection diffusion multilayer method (ADMM), variable separation technique, Fourier transform, square complement method, general integrated transport technique (GITT) and Laplace transform. This work considers the wind speed u, crosswind eddy diffusivity $${k}_{y}$$ k y and vertical eddy diffusivity $${k}_{z}$$ k z as functions of power law in vertical distance "$$z$$ z ". This consideration was applied to the two analytical models. The predicted concentrations were calculated for neutral, stable and unstable conditions. The calculated concentrations for unstable conditions were compared with already existing experimental data measured for radioactive iodine-135 (I135) at an Egyptian Atomic Energy Authority test at Inshas. Also, the calculated concentrations for stable and neutral conditions were compared with already existing experimental data on iodine I-131 (I131) released from the research reactor. A comparison of the values of the proposed concentrations and the previous works is included in this article. It was found that the second predicted model was in good agreement with observed data in unstable, stable and neutral conditions compared with the first predicted model.
Khaled S. M. Essa and Sawsan I. M. El Saied
Wiley
KHALED ESSA, SAWSAN ELSAIED, AYMAN KHALIFA, and ALI WHEIDA
India Meteorological Department
In this paper, comparing between Gaussian plume models and the solution of Advection-diffusion equation in three dimensions using different shapes of dispersion parameters and eddy diffusivities respectively. After that, comparing between Gaussian plume model, proposed model and observed concentrations data which measuring on Egyptian Atomic Energy Authority EAEA for Iodine-135 (I135) in unstable condition.
K.S.M. Essa, MahaS. El-Otaify, SoadM. Etman, and A.A. Marrouf
India Meteorological Department
Khaled S M Essa, Ahmed M Mosallem, and H M Taha
IOP Publishing
Abstract The pollutants from the environment are absorbed by wet deposition which increases the pollutants transport. To create and produce different substances, the constituent atoms of the reactants should be rearranged by the chemical reaction. The introduced theoretical model demonstrate the dispersal of pollutants inherited from point and line source without and with both wet deposition and chemical reaction, respectively. The advection-diffusion equation is solved. Taking the wind speed is a function of downwind distance, lateral eddy diffusivity is a function of wind speed and vertical eddy diffusivity is a function of both wind speed and vertical height of power “z”. In this paper the variable separable method and Hankel transform are used to get the concentration from point and line source. Predicted concentration of pollutants in unstable condition is done. Variation concentrations of both observed and predicted of radioactive Iodine135 (I-135), inside Research Reactor at Inshas Egyptian Atomic Energy Authority, in unstable condition is shown without chemical reaction and wet deposition. It is discovered that the proposed model is a good harmony with observed concentrations data and the proposed data inside a factor of two. Also, studying the effect of wet deposition and chemical reaction on concentration of air contaminants of line source is analysed.
Khaled S. M. Essa, Soad M. Etman, Maha S. El-Otaify, M. Embaby, Ahmed M. Mosallem, and Ahmed S. Shalaby
Springer Science and Business Media LLC
AbstractIn this report, we solved the advection–diffusion equation under pollutants deposition on the ground surface, taking wind speed and vertical diffusion depend on the vertical height. Also, we estimated a simple diffusion model from point source in an urban atmosphere and the conservative material with downwind was evaluated. Then, we calculated the extreme ground-level concentration as a function of stack height and plume rise in two cases. Comparison between the proposed models and the emission from the Egyptian Atomic Research Reactor at Inshas had been done. Lastly, we discussed the results in this report.
Khaled S. M. Essa, Ahmed M. Mosallem, and Ahmed S. Shalaby
Wiley
Khaled S. M. Essa, Ahmed S. Shalaby, Mahmoud A. E. Ibrahim, and Ahmed M. Mosallem
Springer Science and Business Media LLC
Hankel transform was employed to solve the two-dimensional steady state advection–diffusion equation considering a continuous point source with vertical eddy diffusivity as a power law of vertical height and downwind distance, also, taking wind speed as power law. The analytical model was evaluated and compared with Hanford diffusion experiment in stable conditions and Copenhagen diffusion experiment in unstable and neutral conditions which was done by reducing the general analytical model to a one with linear vertical eddy diffusivity and constant downwind speed profile. Comparison with other analytical models was held. The presented model predictions show a good agreement with observations and lay inside a factor of two with observed data of both Hanford and Copenhagen diffusion experiments.
Mamdouh Higazy, Khaled S. M. Essa, Fawzia Mubarak, El-Sayed M. El-Sayed, Abdelsattar M. Sallam, and Mona S. Talaat
Springer Science and Business Media LLC
Arab Abu Saed area in Giza governorate, south to Cairo contains more than 228 clay brick kilns represent the largest cluster of brickworks in Egypt. Burning of Heavy Fuel Oil (HFO) in such kilns is the main source of air pollution in the surrounding locations. In this study, investigation of switching the fuel used in brick kilns from (HFO) to Natural Gas (NG) is carried out and the pollution loads are assessed in both cases. In addition, two Gaussian dispersion plume models are employed to estimate the concentration of primary pollutants; PM10, SO2, and NO2 at seven locations in the vicinity of Arab Abu Saed to determine the most adversely affected locations. Statistical analysis is applied to evaluate the correlation and conformity of the results of both models. Results show that using of NG leads to a significant reduction of pollution loads of PM10, SO2 and NO2 reaches 96%, 72%, and 24% respectively. In addition, the reduction of naturally occurring radionuclides in air is analyzed. Activity concentrations of Ra-226, Th-232 and K-40 in Bq/l for HFO were measured using HPGe detector for six HFO samples. Exposure due to air submersion of naturally occurring radionuclides in the study area leads to annual equivalent dose ranged between 2.16 mSv/y (received by Uterus) and 14 mSv/y (received by skin), and average effective dose 2.65 mSv/y which represent valuable exposure.
Khaled S. M. Essa, Soad M. Etman, and Maha S. El-Otaify
FapUNIFESP (SciELO)
An analytical solution of the three dimensional advection-diffusion equations has been formulated to simulate the dispersion of pollutants in the planetary boundary layer. The solution is based on the assumption that the concentration distribution of pollutants in the crosswind direction has a Gaussian shape and the wind speed is constant. The analytical solution has been obtained in two cases where, the vertical eddy diffusivity is taken to be dependent on: (a) the downwind distance x only and (b) the vertical height z only. The dry deposition of the diffusing particles on the ground is taken into account throughout the boundary conditions. The resulting analytical formulae have been applied to calculate the concentration of I-131 using data collected from the experiments conducted to collect air samples around the Research Reactor. Statistical measures are utilized in the comparison between the predicted and observed concentrations. The results are discussed and presented in tables and illustrative figures.
M.ABDEL WAHAB, KHALED SMESSA, M. EMBABY, and SAWSAN EMELSAID
India Meteorological Department
bl 'kks/k i= esa fu"izHkkoh vkSj vfLFkj fLFkfr;ksa esa ØkWliou lekdfyr lkanz.k ysus ds fy, nks fn’kkvksa esa vfHkogu folj.k lehdj.k ¼ADE½ dks gy fd;k x;k gSA ykIykl :ikarj.k rduhd dk mi;ksx rFkk m/okZ/kj Å¡pkbZ ij vk/kkfjr iou xfr vkSj Hkaoj folj.k’khyrk dh leh{kk djrs gq, ;g gy fudkyk x;k gSA blds lkFk gh Hkw&Lrj vkSj vf/kdre lkanz.kksa dk Hkh vkdyu fd;k x;k gSA geus bl ekWMy esa iwokZuqekfur vkSj izsf{kr lkanz.k vk¡dM+ksa ds e/; rqyuk djus ds fy, dksiugsxu ¼MsuekdZ½ ls fy, x, vkuqHkfod vk¡dM+ksa dk mi;ksx fd;k gSA
 The advection diffusion equation (ADE) is solved in two directions to obtain the crosswind integrated concentration in neutral and unstable conditions. The solution is solved using Laplace transformation technique and considering the wind speed and eddy diffusivity depending on the vertical height. Also the ground level and maximum concentrations are estimated. We use in this model empirical data from Copenhagen (Denmark) to compare between predicted and observed concentration data.
KHALED SMESSA and SOAD METMAN
India Meteorological Department
LFkkuh; Lrj izdh.kZu ds fy, xkSlh;u fiPNd ekWMy ¼Gaussian Plume Model½ dk O;kid :i ls iz;ksx fd;k tkrk gSA vuqizLFk iou dh dqy lkanzrk Kkr djus ds fy, xkSlh;u lw= ¼QkWewyk½ dks laxfBr fd;k gSA vuqizLFk iou dh dqy lkanzrk dh x.kuk djus ds fy, izdh.kZu izkpyksa dh fHkUu&fHkUu iz.kkfy;ksa dk mi;ksx fd;k x;k gSA lrg Lrj esa Å¡pkbZ ds vuqlkj iou xfr dh fHkUurk dk o.kZu djus ds fy, ykxfjFehd foaM izksQkby dk mi;ksx fd;k x;k gSA blesa NksM+h tkus okyh izHkkoh Å¡pkbZ dks /;ku esa j[kk x;k gSA fHkUu fHkUu izdh.kZu izkpy iz.kkfy;ksa ds fy, iwokZuqekfur lkanzrkvksa vkSj dksisugsxu ds folj.k iz;ksx ls izkIr fd, x, izsf{kr vk¡dM+ksa dh rqyuk djus ds fy, lkaf[;dh; ifjekiksa dk mi;ksx fd;k x;k gSA
 The Gaussian plume model is the most widely used model for local scale dispersion. The Gaussian formula has been integrated to obtain the crosswind-integrated concentration. Different systems of dispersion parameters are used to calculate the crosswind integrated concentration. A logarithmic wind profile is used to describe the variation of wind speed with height in the surface layer. The effective release height was taken into consideration. Statistical measures are utilized in the comparison between the predicted concentrations for different dispersion parameter systems and the observed concentrations data obtained from Copenhagen diffusion experiment.
M. Abdel-Wahab, K. S. M. Essa, M. Embaby, and S. E. M. Elsaid
Oxford University Press (OUP)
The investigated work aims to calculate the concentration of different isotopes through short downwind distances. A theoretical model was designed to calculate the isotope concentration in the wind. The mathematical calculation depends on wind speed, decay distance and the dilution factor to get the concentration of isotopes ((131)I, (133)I, (135)I and (137)Cs) detected in wind at different distances from a nuclear power station. There is a good agreement between the calculated and observed concentrations of (131)I, (133)I, (135)I and (137)Cs.