doi:10.24996/ijs.2023.64.6.24

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Publication Date

Fri Jun 30 2023

Journal Name

Iraqi Journal Of Science

Volume

64

Issue Number

6

DOI

10.24996/ijs.2023.64.6.24

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Evaluation of Vanadium Contamination in Some Soils of the East Baghdad Oil Field

Vanadium

East Baghdad oil field

Soil

Contamination

Spatial distribution

Hadeel Mazin

Firas Mudhafar

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Since oil is the primary source of vanadium in the environment and crude oil has a correspondingly high percentage of vanadium. Vanadium is crucial as a sign of oil contamination. Twenty soil samples were taken from various locations surrounding the East Baghdad oil field in Iraq during February 2022 and then analyzed to determine the effects of industrialization along with urbanization-related pollutants. The soil samples were analyzed using spectrophotometry analysis. In soil samples taken from the research area, vanadium concentrations range from (0.26 to 1.2 ppm). The contamination (CF), geoaccumulation (Igeo) and Enrichment factors (EF) indicated that all the soil samples are uncontaminated.

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Publication Date

Thu Dec 30 2021

Journal Name

Iraqi Journal Of Science

Gompertz Fréchet stress-strength Reliability Estimation

Reliability

Stress- Strength

Gompertz Fréchet Distribution

Maximum Likelihood Estimator

Least square Estimator

Weighted Least square Estimator

Regression Estimator

Ranked set sampling estimator

Sarah A.

Nada S.

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In this paper, the reliability of the stress-strength model is derived for probability P(Y<X) of a component having its strength X exposed to one independent stress Y, when X and Y are following Gompertz Fréchet distribution with unknown shape parameters and known parameters . Different methods were used to estimate reliability R and Gompertz Fréchet distribution parameters, which are maximum likelihood, least square, weighted least square, regression, and ranked set sampling. Also, a comparison of these estimators was made by a simulation study based on mean square error (MSE) criteria. The comparison confirms that the performance of the maximum likelihood estimator is better than that of the other estimators.

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(4)

Publication Date

Mon May 04 2020

Journal Name

Offshore Technology Conference

Hydrate Equilibrium Model for Gas Mixtures Containing Methane, Nitrogen and Carbon Dioxide

gas hydrate

cavity

equilibrium condition

flow assurance

modeling & simulation

hydrate equilibrium condition

upstream oil & gas

cage occupancy

hydrate

gas mixture

Dhifaf Jaafar

Omar

Stefan

Maxim

Callum

Ahmed

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AbstractGas hydrate formation is considered one of the major problems facing the oil and gas industry as it poses a significant threat to the production, transportation and processing of natural gas. These solid structures can nucleate and agglomerate gradually so that a large cluster of hydrate is formed, which can clog flow lines, chokes, valves, and other production facilities. Thus, an accurate predictive model is necessary for designing natural gas production systems at safe operating conditions and mitigating the issues induced by the formation of hydrates. In this context, a thermodynamic model for gas hydrate equilibrium conditions and cage occupancies of N2 + CH4 and N2 + CO4 gas mix ... Show More

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(6)

Publication Date

Thu Mar 18 2010

Journal Name

Spe Projects, Facilities & Construction

Correlating Optimum Stage Pressure for Sequential Separator Systems

separation and treating

PVT measurement

optimization problem

Upstream Oil & Gas

Phase Behavior

objective function

optimum stage pressure

GOR

Artificial Intelligence

Mohammed S.

Omar

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SummaryA study to find the optimum separators pressures of separation stations has been performed. Stage separation of oil and gas is accomplished with a series of separators operating at sequentially reduced pressures. Liquid is discharged from a higher-pressure separator into the lower-pressure separator. The set of working separator pressures that yields maximum recovery of liquid hydrocarbon from the well fluid is the optimum set of pressures, which is the target of this work.A computer model is used to find the optimum separator pressures. The model employs the Peng-Robinson equation of state (Peng and Robinson 1976) for volatile oil. The application of t ... Show More

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(13)

Publication Date

Tue Oct 20 2020

Journal Name

Ibn Al-haitham Journal For Pure And Applied Sciences

Comparison Among Three Estimation Methods to Estimate Cascade Reliability Model (2+1) Based On Inverted Exponential Distribution

inverted exponential distribution

Maximum Likelihood method

Uniformly Minimum Variance Unbiased method

Single Stage Shrinkage Estimator

Mean Squared Error and Cascade Reliability Model (2 1)

Sairan

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In this paper, we are mainly concerned with estimating cascade reliability model (2+1) based on inverted exponential distribution and comparing among the estimation methods that are used . The maximum likelihood estimator and uniformly minimum variance unbiased estimators are used to get of the strengths and the stress ;k=1,2,3 respectively then, by using the unbiased estimators, we propose Preliminary test single stage shrinkage (PTSSS) estimator when a prior knowledge is available for the scale parameter as initial value due past experiences . The Mean Squared Error [MSE] for the proposed estimator is derived to compare among the methods. Numerical results about conduct of the considered

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Publication Date

Sun Oct 02 2022

Journal Name

Al-manhaj

Mathematical Statistics - Second Edition

Mathematical Expectation

Moment Generating Function

Cumulative Distribution Function

Probability Mass Function

Probability Density Function

Discrete Distributions

Continuous Distributions

Joint distributions

Marginal Distributions

Conditional Distributions

Transformations

Order Statistics.

Omar Abdulmohsin

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This Book is the second edition that intended to be textbook studied for undergraduate/ postgraduate course in mathematical statistics. In order to achieve the goals of the book, it is divided into the following chapters. Chapter One introduces events and probability review. Chapter Two devotes to random variables in their two types: discrete and continuous with definitions of probability mass function, probability density function and cumulative distribution function as well. Chapter Three discusses mathematical expectation with its special types such as: moments, moment generating function and other related topics. Chapter Four deals with some special discrete distributions: (Discrete Uniform, Bernoulli, Binomial, Poisson, Geometric, Neg

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Publication Date

Sun Jun 01 2014

Journal Name

Journal Of Economics And Administrative Sciences

Different Methods for Estimating Location Parameter & Scale Parameter for Extreme Value Distribution

Extreme Value Distribution

Maximum likelihood estimator

Method of moment Estimators

Estimators based on Percentiles

Least Squares estimators

Weighted Least Squares estimators

Ridge regression estimators

Adjusted Ridge regression estimators.

جنان عباس

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In this study, different methods were used for estimating location parameter and scale parameter for extreme value distribution, such as maximum likelihood estimation (MLE) , method of moment estimation (ME),and approximation estimators based on percentiles which is called white method in estimation, as the extreme value distribution is one of exponential distributions. Least squares estimation (OLS) was used, weighted least squares estimation (WLS), ridge regression estimation (Rig), and adjusted ridge regression estimation (ARig) were used. Two parameters for expected value to the percentile as estimation for distribution f

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Publication Date

Wed Apr 25 2018

Journal Name

Ibn Al-haitham Journal For Pure And Applied Sciences

Different Estimation Methods for System Reliability Multi-Components model: Exponentiated Weibull Distribution

Exponentiated Weibull Distribution (EWD)

Reliability of multi-component Stress â€“ Strength models R(s

k)

Maximum likelihood estimator (MLE)

Moment estimator (MOM)

shrinkage method (Sh)

Least Squares Estimator (LS)

Rank Set Sampling (RSS). and mean squared error (MSE).

Abbas Najim

Fatima Hadi

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In this paper, estimation of system reliability of the multi-components in stress-strength model R_(s,k) is considered, when the stress and strength are independent random variables and follows the Exponentiated Weibull Distribution (EWD) with known first shape parameter Î¸ and, the second shape parameter Î± is unknown using different estimation methods. Comparisons among the proposed estimators through Monte Carlo simulation technique were made depend on mean squared error (MSE) criteria

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