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A Comparison of Different Estimation Methods to Handle Missing Data in Explanatory Variables
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Missing data is one of the problems that may occur in regression models. This problem is usually handled by deletion mechanism available in statistical software. This method reduces statistical inference values because deletion affects sample size. In this paper, Expectation Maximization algorithm (EM), Multicycle-Expectation-Conditional Maximization algorithm (MC-ECM), Expectation-Conditional Maximization Either (ECME), and Recurrent Neural Networks (RNN) are used to estimate multiple regression models when explanatory variables have some missing values. Experimental dataset were generated using Visual Basic programming language with missing values of explanatory variables according to a missing mechanism at random general pattern and some ratios of missing values (10%, 20%, and 30%) with error variance values of 0.5, 1. 5, and 2, which were included in sample sizes of 25, 50, 100, and 500 and evaluated using Mean Squared Error (MSE). Simulation results show that RNN outperforms the other methods, followed by EM at small sample sizes.

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Publication Date
Sat Mar 17 2012
Journal Name
Environmental Science And Pollution Research Volume
Equilibrium, kinetic, and thermodynamic biosorption of Pb(II), Cr(III), and Cd(II) ions by dead anaerobic biomass from synthetic wastewater
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Purpose Heavy metals are toxic pollutants released into the environment as a result of different industrial activities. Biosorption of heavy metals from aqueous solutions is a new technology for the treatment of industrial wastewater. The aim of the present research is to highlight the basic biosorption theory to heavy metal removal. Materials and methods Heterogeneous cultures mostly dried anaerobic bacteria, yeast (fungi), and protozoa were used as low-cost material to remove metallic cations Pb(II), Cr(III), and Cd(II) from synthetic wastewater. Competitive biosorption of these metals was studied. Results The main biosorption mechanisms were complexation and physical adsorption onto natural active functional groups. It is observed that

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Publication Date
Thu Nov 22 2018
Journal Name
Al-khwarizmi Engineering Journal
Experimental and Finite Elements Analysis Study of Warming Effect on Deboned Force for Embedded NiTinol Wire into Linear Low Density Polyethylene
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This study presents the debonding propagation in single NiTi wire shape memory alloy into linear low-density polyethylene matrix composite the study of using the pull-out test. The aim of this study is to investigate the pull-out tests to check the interfacial strength of the polymer composite in two cases, with activation NiTinol wire and without activation. In this study, shape memory alloy NiTinol wire 2 mm diameter and linear fully annealed straight shape were used. The study involved experimental and finite element analysis and eventually comparison between them. This pull-out test is considered a substantial test because its results have a relation with behavior of smart composite materials. The pull-out test was carried out by a u

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Publication Date
Sun Mar 01 2020
Journal Name
International Journal Of Pharmaceutical Research
Phytochemical investigation,anti-proliferative and antioxidant- activities of Iraqi Capparisspinosa L. (Family Capparidaceae) against MCF-7 human Breast cancer cell line
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Publication Date
Mon Feb 13 2023
Journal Name
Journal Of Educational And Psychological Researches
Evaluation of English Language Textbooks for Fifth and Sixth Graders Based on the American Council Criteria for Teaching Foreign Languages (ACTFL)
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Abstract

This study aims to identify the extent to which the criteria of the American Council for Teaching Foreign Languages (ACTFL) are included in the English language books for the fifth and sixth graders. To achieve the objective of the study, a content analysis card was prepared, where the classification of language proficiencies was divided into five main levels (beginner, intermediate, advanced, superior, and distinguished) of the four language skills (listening, speaking, reading, and writing), The content analysis card consisted of (89) indicators distributed at the four levels of language skills as follows: Listening (17), speaking (33), reading (15), and writing (26). The study sample consisted of Engl

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Publication Date
Sun Sep 03 2017
Journal Name
Baghdad Science Journal
Kinetic and Mechanistic Studies for the Gas-phase Reaction of Ozone with 2, 3-Dimethyl-2-Butene and 1, 3-Butadiene
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The reactions of ozone with 2,3-Dimethyl-2-Butene (CH3)2C=C(CH3)2 and 1,3-Butadiene CH2=CHCH=CH2 have been investigated under atmospheric conditions at 298±3K in air using both relative and absolute rate techniques, and the measured rate coefficients are found to be in good agreement in both techniques used. The obtained results show the addition of ozone to the double bond in these compounds and how it acts as function of the methyl group substituent situated on the double bond. The yields of all the main products have been determined using FTIR and GC-FID and the product studies of these reactions establish a very good idea for the decomposition pathways for the primary formed compounds (ozonides) and give a good information for the effe

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Publication Date
Wed Jan 05 2022
Journal Name
Iraqi Journal Of Science
The Inhibition Activity of Silver Nanoparticles Compared with D-Glycin and Imipenem Effect on the Biofilm Formation by Food-origin Salmonella
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Since decades silver was depended worldwide as a treatment to a lot of diseases
ranging from burn infections, anthrax, and typhoid fever to bacterial conjunctivitis
in stillbirth, but its effectiveness against biofilms is still undetermined. Salmonella is
a major cause of food poisoning outbreaks especially in the third world countries.
Thus, in the present study; the antimicrobial activity of silver nanoparticles (Ag-
NPs) against Salmonella enterica biofilm was examined; their activity was
compared with amino acid; D-Glycin and imipenem antibiotic. The result of the
study revealed that Ag-NPs exhibited considerable antimicrobial property against
Salmonella enterica biofilm where the minimum inhibitory concentrat

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Publication Date
Sun Mar 03 2013
Journal Name
Baghdad Science Journal
Preparation, Characterization and Spectroscopic Study of New Tridentate Schiff Base and its Cu(II), Ni(II) and Zn(II) Metal Complexes
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A new tridentate ligand has been synthesized derived from phenyl(pyridin-3-yl)methanone. Three coordinated metal complexes were prepared by complexation of the new ligand with Cu(II), Ni(II) and Zn(II) metal salts. The new Schiff base “benzyl -2-[phenyl(pyridin-3-yl)methylidene]hydrazinecarbodithioate” and the new metal complexes were characterized using various physico-chemical and spectroscopic techniques. From the analysis results, the expected structure to the metal complexes are octahedral in geometry for Cu(II) complex, square planner for Ni(II) and tetrahedral for Zn(II) complex. The new compounds are expected to show strong bioactivity against bacteria and cancer cells.

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Publication Date
Wed Jan 22 2025
Journal Name
Journal Of Baghdad College Of Dentistry
The validity of salivary microRNAs (hsa-miR-200a, hsa-miR-125a and hsa- miR-93) as oral squamous cell carcinoma biomarker
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Background: Oral squamous cell carcinoma represents the vast majority of oral cancer it is a common malignant tumor with an increasing incidence. Around the world, the 5 year mortality rate of oral cancer is about 50%. Thus novel biomarkers for early detection oral squamous cell carcinoma are needed. The level of three salivary microRNAs namely hsa-miR-200a, hsa-miR-125a and hsa- miR-93 were measured in saliva of patients with oral squamous cell carcinoma and compared their levels in saliva of healthy control subjects to determine their potential as oral cancer biomarker. Materials and methods: The level of these three microRNAs was measured by using revers transcription, preamplification and quantitative PCR. Results: Only miR-200a presen

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Publication Date
Sun Mar 02 2014
Journal Name
Baghdad Science Journal
An Approximated Solutions for nth Order Linear Delay Integro-Differential Equations of Convolution Type Using B-Spline Functions and Weddle Method
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The paper is devoted to solve nth order linear delay integro-differential equations of convolution type (DIDE's-CT) using collocation method with the aid of B-spline functions. A new algorithm with the aid of Matlab language is derived to treat numerically three types (retarded, neutral and mixed) of nth order linear DIDE's-CT using B-spline functions and Weddle rule for calculating the required integrals for these equations. Comparison between approximated and exact results has been given in test examples with suitable graphing for every example for solving three types of linear DIDE's-CT of different orders for conciliated the accuracy of the results of the proposed method.

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Publication Date
Sun Sep 15 2024
Journal Name
Advanced Journal Of Chemistry, Section A
Synthesis, Characterization and Study the Liquid Crystalline Properties of Some New Bent Compounds Derived from Diethylpyrimidine-2,4,6(1H,3H,5H)-Trione
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This article includes designed and synthesized for bent-shaped liquid crystal molecules starting from 5,5-diethylpyrimidine-2,4,6(1H,3H,5H)-trione and two moles of chloroacetylchloride in N, N-dimethyl formamide (DMF) and triethylamine (TEA) to product compound [I] ,then reacted the later compound with two moles of 4-hydroxybenzonitrile to yield nitrile compound [II]. Likewise, reaction 5,5-diethylpyrimidine-2,4,6(1H,3H,5H)-trione and two moles of ethylchloroacetate with fused sodium acetate in ethanol to create an ester compound [III], and then the later compound was reacted with two moles of hydrazine hydrate in ethanol to obtained hydrazide acid compound [IV]. After that, the compound [IV] reacted with two moles of ethyl acetoacetate in

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