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Performance Evaluation of Three Phase Spray Direct Contact Heat Exchanger
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The present investigation deals with experimental study of three-phase direct-contact heat exchanger, for water-Freon R11 system, where water is the continuous phase (liquid) and Freon R11 (liquid-gas) is the dispersed phase. The test section consisted of a cylindrical Perspex column with inner diameter 8cm and 1.2m long, in which, water was to be confined. Liquid Freon R11 drops were injected into the hot water filled column, through a special design of distributors at the bottom of the column. The liquid Freon R11 drops rose on their way up and evaporated into two-phase bubbles at atmospheric pressure. The study was devoted to express the effect of process variables such as column height, Freon R11 mass flow rate and initial temperature of water on the average percentage holdup, heat transfer rate, volumetric heat transfer coefficient and effectiveness.

The obtained experimental results showed that the average percentage holdup increased with increasing in the process variables. The heat transfer rate increased clearly with increasing in mass flow rate of Freon R11 while it increased very little when column height and initial temperature of water increased, it increased two times when increase the mass flow rate from 1.8 to 5.4 kg/hr. The volumetric heat transfer coefficient was found to decrease with increasing in column height and initial temperature of water, while it was increased with increasing in mass flow rate of Freon R11. The effectiveness was found to increase (maximum 90%) with increasing in column height and decreasing in the mass flow rate of Freon R11 and initial temperature of water. A statistical analysis was performed to get general correlations for the average percentage holdup, heat transfer rate, volumetric heat transfer coefficient and effectiveness as a function of the studied parameters.

 

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Publication Date
Wed Sep 30 2015
Journal Name
European Journal Of Chemistry
Reaction pathways and transition states of the C-C and C-H bond cleavage in the aromatic pyrenemolecule - A Density Functional study
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The activation and reaction energies of the C-C and C-H bonds cleavage in pyrene molecule are calculated applying the Density Functional Theory and 6-311G Gaussian basis. Different values for the energies result for the different bonds, depending on the location of the bond and the structure of the corresponding transition states. The C-C bond cleavage reactions include H atom migration, in many cases, leading to the formation of CH2 groups and H-C≡C- acetylenic fragments. The activation energy values of the C-C reactions are greater than 190.00 kcal/mol for all bonds, those for the C-H bonds are greater than 160.00 kcal/mol. The reaction energy values for the C-C bonds range between 56.497 to 191.503 kcal/mol. As for the C-H cleavage rea

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Publication Date
Sat Jun 18 2022
Journal Name
Sciencescholar Publication
Logical reasoning skills according to Piaget's model for chemistry students in the college of education for pure sciences Ibn al-Haytham in
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Abstract---The aim of the current research is to identify the level of logical reasoning skills in chemistry students at the Faculty of Education for Pure Sciences/ Ibn Al-Haytham for the academic year (2021-2022). The differences in their level of skills according to the gender variable (males and females) and the academic stages (first- second - third - fourth). The descriptive approach was adopted because it corresponds to the nature of the research objectives. The research sample consisted of (400 )students selected in a relatively random stratified way. The researcher constructed a logical reasoning test, which includes (6) sub-skills , which is (proportional - probabilistic- synthetic- deductive- logic- variable adjustment). The psych

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Publication Date
Thu Dec 01 2011
Journal Name
Journal Of Economics And Administrative Sciences
Organizational Transparency influence in reducing administrative corruption financially studing analytcal analysts of the same man from the upper leaders in iraqi Organizations
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The Organizational Transparency is regarded one of the effective means in the attempts of the restoration and working to prevent the corruption and reduce the negative managerial economic social and political effects.

Accordingly, this study aims at importance of performing an explorative analytical study in order to stand on the effect of the Organizational Transparency in the reduction of environment of Iraqi Organizations.

To achieve this study, three hypotheses were chosen; the first is the correlation relation and the second is the effect and the third is the differences, and statistical means represented by correlation coefficient "Spearman", "", "Mann- Whit

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Publication Date
Wed Nov 01 2017
Journal Name
Research Journal Of Pharmaceutical, Biological And Chemical Sciences
Preparation, Spectral studies and Biological Efficiency of Metal (II) Mixed Ligand Complexes Schiff Base derived from (Benzaldehyde and OAminoaniline) with 8-Hydroxyquinoline
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fication of benzaldehyde (C6H5CHO) and O- amino aniline O-C6H4(NH2)2 in ethanol with 8- Hydroxyquinoline (8HQ) . Formed compounds were acquired of 1:1:2 molar proportion reactions for metal ions and ligands (L) and 2(8HQ) during reaction for MCl2 .nH2O salt products complexes conformable into the forms [M(L)(8HQ)2] ,where M = Mn(II),Co(II) and Ni(II). Whole the compounds were identified during the basis of their; FT-IR and U.V spectrum, melting point, molar conduct, identify of the percentage from the metal at the complexes via flame (AAS), C, H and N content of the Schiff base (L) and metal complexes were analysis and magnetic susceptibility menstruations. A hexagonal coordinated metal complexes were proposed to the separated complexes of

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Publication Date
Wed May 19 2010
Journal Name
Journal Of College Of Science, University Of Babylon
H-Point Standard Addition Method for Simultaneous Determination of Cimetidine and Erythromycin Ethylsuccinate Drugs Using Bromothymol Blue as a Chromogenic Complexing Agent
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The H-Point Standard Addition Method (H-PSAM) has been applied for spectrophotometric simultaneous determination of Cimetidine and Erythromycin ethylsuccinate using Bromothymol Blue (BTB) as a chromogenic complexing agent in a buffer solution at pH 5.5.

Publication Date
Mon Oct 31 2016
Journal Name
International Journal Of Advanced Research
SINGLE NUCLEOTIDE POLYMORPHISMS (SNPS) IN EXON 3 AND 7 OF ESTROGEN RECEPTOR BETA (ESR2) GENE IN WOMEN WITH BREAST CANCER FROM IRAQ.
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This study was aimed to determine the mutations and single nucleotide polymorphisms (SNPs) in exon 3 and 7 of estrogen receptor beta (ESR2) gene in women with breast cancer from Iraq. Different samples (blood, fresh tissue with blood from same patient, and formalin fixed paraffin embedded, FFPE) were collected from women with breast cancer. Molecular analysis exon 3 and 7 in ESR2 has been studied by using PCR. It was found exon 3 and 7 in ESR2 were revealed as a single band with size 151 and 157 bp, respectively. There was no SNP in exon 3 has been identified. While three novel polymorphisms (ACT, AGG and GCA) were detected in exon 7, the type of those polymorphisms deletion for ACT and AGG while substitution polymorphism for GCA. From this

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Publication Date
Sun Jul 01 2012
Journal Name
International Journal Of Computer Mathematics
Numerical solution of the two-dimensional Helmholtz equation with variable coefficients by the radial integration boundary integral and integro-differential equation methods
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Publication Date
Tue Jan 01 2019
Journal Name
International Journal Of Research In Social Sciences And Humanities
A DISCOURSE ANALYSIS STUDY OF THE TRUTH AND REALITY IN NEWS WEBSITES ABOUT THE WARIN SYRIABETWEEN AL-JAZEERA ENGLISH AND BBC WORLD
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BN Rashid, International Journal of Research in Social Sciences and Humanities, 2019 - Cited by 1

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Publication Date
Tue Jan 20 2026
Journal Name
Journal Of Baghdad College Of Dentistry
Beta angle in a sample of Iraqi adults with Class I skeletal and dental relations and its correlation with other craniofacial measurements
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Background: This study aimed to determine the value of Beta angle for a sample of Iraqi adults with class I skeletal and dental relations and to verify the existence of sexual dimorphism and to find out the relation between this angle and other craniofacial measurements. Materials and Methods: Sixty dental students (23 males and 37 females) with an age ranged between 20-31 years old and having class I skeletal and dental relations were chosen for this study. Each student was subjected to clinical examination and digital true lateral cephalometric radiograph. The radiographs were analyzed using AutoCAD 2007 computer program to measure the angular and linear variables. Descriptive statistics were obtained for the measurements for both genders

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Publication Date
Thu Sep 15 2022
Journal Name
Journal Of Baghdad College Of Dentistry
The push out bond strength of bioceramic seal-er(Total Fill) after warm and cold obturation tech-niques An in vitro comparative
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Background: The goal of a root canal treatment is three dimensional obturation with a complete seal of the root canal system. The aim of this study was to evaluate and compare the effect of two warm obturation techniques, warm vertical compaction (WVC) and, carrier based obturation technique Gutta Core (GC), versus two cold obturation techniques, cold lateral compaction (CLC) and, single cone (SC) on push-out bond strength of bioceramic sealer (Total Fill) at three different root levels. Materials and Methods: Forty extracted maxillary first molars teeth with a straight round palatal root canal and mature apices were selected for this study. After sectioning the palatal roots to 11 mm from the root apex, the canals were prepared wit

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