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Publication Date

Fri Dec 08 2023

Journal Name

Iraqi Journal Of Science

Volume

55

Issue Number

1

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A Modified Hestenes-Stiefel Conjugate Gradient Method and its Global convergence for unconstrained optimization

Conjugate gradient

modified secant condition

decent property

global convergence

non-quadratic model.

Ghada

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In this paper, we proposed a modified Hestenes-Stiefel (HS) conjugate
gradient method. This achieves a high order accuracy in approximating the second
order curvature information of the objective function by utilizing the modified
secant condition which is proposed by Babaie-Kafaki [1], also we derive a nonquadratic
conjugate gradient model. The important property of the suggestion
method that is satisfy the descent property and global convergence independent of
the accuracy of the line search. In addition, we prove the global convergence under
some suitable conditions, and we reported the numerical results under these
conditions.

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Publication Date

Mon May 23 2022

Journal Name

International Journal Of Molecular Sciences

Physoxia Influences Global and Gene-Specific Methylation in Pluripotent Stem Cells

Fatma

Rakad M. Kh

Mark

Nicholas R.

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Pluripotent stem cells (PSC) possess unlimited proliferation, self-renewal, and a differentiation capacity spanning all germ layers. Appropriate culture conditions are important for the maintenance of self-renewal, pluripotency, proliferation, differentiation, and epigenetic states. Oxygen concentrations vary across different human tissues depending on precise cell location and proximity to vascularisation. The bulk of PSC culture-based research is performed in a physiologically hyperoxic, air oxygen (21% O2) environment, with numerous reports now detailing the impact of a physiologic normoxia (physoxia), low oxygen culture in the maintenance of stemness, survival, morphology, proliferation, differentiation potential, and epigenetic

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Publication Date

Mon Jan 13 2020

Journal Name

Day 3 Wed, January 15, 2020

Numerical Simulation of Gas Lift Optimization Using Genetic Algorithm for a Middle East Oil Field: Feasibility Study

Constrained optimization

Gas lifts

Gases

Gasoline

Genetic algorithms

Life cycle

Natural gas fields

Numerical models

Offshore oil well production

Oil fields

Mustafa

Mofazzal

Omar

Akim

Abbas

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<p>Gas-lift technique plays an important role in sustaining oil production, especially from a mature field when the reservoirs’ natural energy becomes insufficient. However, optimally allocation of the gas injection rate in a large field through its gas-lift network system towards maximization of oil production rate is a challenging task. The conventional gas-lift optimization problems may become inefficient and incapable of modelling the gas-lift optimization in a large network system with problems associated with multi-objective, multi-constrained, and limited gas injection rate. The key objective of this study is to assess the feasibility of utilizing the Genetic Algorithm (GA) technique to optimize t</p> ... Show More

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Publication Date

Sat Jul 08 2017

Journal Name

Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)

A Highly Sensitive Kinetic-Spectrophotometric Method for the Assay of Carbamazepine in Pure and Commercial Tablet

Keywords: Kinetic

Spectrophotometry

Carbamazepine

Pharmaceutical formulations.

Sarmad

Faeza

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The study aimed to recommend a new spectrophotometric-kinetic method for determination of carbamazepine (CABZ) in its pure form and pharmaceutical forms. The proposed procedure based on the coupling of CABZ with diazotized sulfanilic acid in basic medium to yield a colored azo dye. Factors affecting the reaction yield were studied and the conditions were optimized. The colored product was followed spectrophotometrically via monitoring its absorbance at 396 nm. Under the optimized conditions, two method (the initial rate and fixed time (10 minute)) were applied for constructing the calibration graphs. The graphs were linear in concentration ranges 2.0 to 18.0 Âµg.mL^-1 for both methods. The proposed was applied successfully in

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Publication Date

Sun Jan 30 2022

Journal Name

Iraqi Journal Of Science

Global Stability of an epidemic model with vaccine involving stage structure

Epidemic model

Stage Structures

Vaccination

Local and Global Sta bility

Mohammed A.

Hassan Fadhil

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In this paper a mathematical model that analytically as well as numerically
the flow of infection disease in a population is proposed and studied. It is
assumed that the disease divided the population into five classes: immature
susceptible individuals (S1) , mature individuals (S2 ) , infectious individual
(I ), removal individuals (R) and vaccine population (V) . The existence,
uniqueness and boundedness of the solution of the model are discussed. The
local and global stability of the model is studied. Finally the global dynamics of
the proposed model is studied numerically.

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Publication Date

Thu Apr 20 2023

Journal Name

Ibn Al-haitham Journal For Pure And Applied Sciences

A Class of Exponential Rayleigh Distribution and New Modified Weighted Exponential Rayleigh Distribution with Statistical Properties

Exponential Rayleigh (ER) distribution

Modified Weighted Exponential Rayleigh (MWER) distribution.

Lamyaa Khalid

Huda

Iden

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This paper deals with the mathematical method for extracting the Exponential Rayleighh distribution based on mixed between the cumulative distribution function of Exponential distribution and the cumulative distribution function of Rayleigh distribution using an application (maximum), as well as derived different statistical properties for distribution, and present a structure of a new distribution based on a modified weighted version of Azzalini’s (1985) named Modified Weighted Exponential Rayleigh distribution such that this new distribution is generalization of the distribution and provide some special models of the distribution, as well as derived different statistical properties for distribution

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Publication Date

Thu Oct 20 2022

Journal Name

Ibn Al-haitham Journal For Pure And Applied Sciences

Solving of the Quadratic Fractional Programming Problems by a Modified Symmetric Fuzzy Approach

modified simplex approach

fuzzy system

modified symmetric fuzzy

QFPP

Maher

Nejmaddin A. Sulaiman

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The aims of the paper are to present a modified symmetric fuzzy approach to find the best workable compromise solution for quadratic fractional programming problems (QFPP) with fuzzy crisp in both the objective functions and the constraints. We introduced a modified symmetric fuzzy by proposing a procedure, that starts first by converting the quadratic fractional programming problems that exist in the objective functions to crisp numbers and then converts the linear function that exists in the constraints to crisp numbers. After that, we applied the fuzzy approach to determine the optimal solution for our quadratic fractional programming problem which is supported theoretically and practically. The computer application for the algo

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Publication Date

Sat Jun 01 2024

Journal Name

Results In Control And Optimization

Impact of wind flow and global warming in the dynamics of prey–predator model

Global warming

Prey–predator system

Nonlinear systems

Ashraf Adnan

Shireen

Salam J.

Kottakkaran Sooppy

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Publication Date

Thu Jan 30 2020

Journal Name

Journal Of Engineering

Current and Modified Flood Discharge Capacity of a Reach of Tigris River between Kut and Amarah Barrages

Tigris River

HEC-RAS model

Flood simulation and Manning’s coefficient

maysam s

Riyadh Z.

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This study was conducted to examine the discharge capacity of the reach of the Tigris River between Kut and Amarah Barrages of 250km in length. The examination includes simulation the current capacity of the reach by using HEC-RAS model. 247cross sections surveyed in 2012 were used in the simulation. The model was calibrated using observed discharges of 533, 800, 1025 and 3000m³/s discharged at Kut Barrage during 2013, 1995, 1995 and 1988, respectively, and its related water level at three gauge stations located along the reach. The result of calibration process indicated that the lowest Root Mean Square Error of 0.095 can be obtained when using Manning’s n coefficient of 0.026, 0.03 for th

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Publication Date

Wed Jan 01 2020

Journal Name

Annals Of Tropical Medicine And Public Health

Synthesis and characterization of new phthalimide with 6- mercaptopurine or 2- aminothiazole conjugate used dithiocarbamate spacer as anticancer agents

Shams A.

Mohammed H.

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Publication Date

Sat Oct 01 2016

Journal Name

Journal Of Theoretical And Applied Information Technology

Factors affecting global virtual teams’ performance in software projects

Today the trend is to perform software development work via distributed geographical area among team

individual or even as an organization. However

due to the global market and international presence of many companies

there is a need to implement a global virtual teams. The global virtual team members are gradually engaged in globalized business environments across space

time and organizational boundaries via information and communication technologies. A global virtual team relies on communication

collaboration

and information exchange are the most important criteria in global virtual teams’ operations. The purpose of this paper is to answer two research questions. The first research question is to identify the factors affecting global virtual teams’ performance. A systematic literature review was conducted to answer the first research question. The second research question is on what the rank of the factor affecting the global virtual teams’ performance according to their level of effect on global virtual teams’ performance. Online survey was conducted within 103 developers and IT managers from eight IT companies to answer the second research question. The Statistical Package for Social Science (SPSS 22) was used to analyze the collected data. In this study

we investigated factors that affect global virtual teams’ performance

factors considered include cultural differences

language problems

time-zone differences

team size

technical problems

lack of trust

lack of sufficient training

and ICT problems. Also the findings indicated that lack of sufficient training is the highest level of effect on global virtual teams’ performance. On the other hand

Ali Yahya Gheni

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