Preferred Language
Articles
/
alkej-90
Study the Dissociation Enthalpies for R134a Clathrate Hydrate in Binary and Ternary Systems
...Show More Authors

In the present work the clathrate hydrate dissociation enthalpies of refrigerant R134a+ water system, and R134a + water + salt system were determined. The heat of dissociation of three types of aqueous salts solutions of NaCl, KBr and NaF at three concentrations (0.09, 0.17and 0.26) mol·kg−1 for each salt type, were enthalpy measured. The Clapeyron equation was used tocalculate heat of dissociation of experimental data for binary and ternary system.In order to find the effect of compressibility factor on heat dissociation enthalpy, the study was conducted by using equation of state proposed by Peng and Robinson Stryjek-Vera (PRSV). The obtained results of dissociation enthalpy for binary system were (143.8) kJ.mol-1 without gas compressibility factor (z) and (136.08) kJ.mol-1 with z where the variation between two values was (5.3%). For ternary system (R134a+ water +NaCl) at three concentrations of this salt, the calculated values were in the range of (146.7 - 154.1) kJ.mol-1without z and (138.02-145.14) kJ.mol-1with z where the variation rang between two values was (5.8-5.7) %. The other two types of salts given similar results within (0.886 - 0.129) % deviation rang about NaCl results without z and (0.818-0.149) % deviation rang with z values.

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Thu Jan 01 2015
Journal Name
Journal Of Nanomaterials
Comparative Studies on Thermal Performance of Conic Cut Twist Tape Inserts with SiO<sub>2</sub>and TiO<sub>2</sub>Nanofluids
...Show More Authors

This paper presents a comparison study on thermal performance conic cut twist tape inserts in laminar flow of nanofluids through a constant heat fluxed tube. Three tape configurations, namely, quadrant cut twisted tape (QCT), parabolic half cut twisted tape (PCT), and triangular cut twisted (VCT) of twist ratioy= 2.93 and cut depthde= 0.5 cm were used with 1% and 2% volume concentration of SiO2/water and TiO

... Show More
View Publication
Scopus (9)
Crossref (7)
Scopus Clarivate Crossref
Publication Date
Sun May 17 2026
Journal Name
Journal Of Baghdad College Of Dentistry
Effect of different palatal vault shapes and woven glass fiber reinforcement on dimensional stability of high impact acrylic denture base [part II]
...Show More Authors

Background: Change in palatal vault shape and Reinforcement of high impact acrylic denture base resin may in turn affect the dimensional accuracy of acrylic resin and affecting the fitness of the denture. The aim of study is to evaluate the effect of fiber reinforcement for high-impact acrylic resin denture base with different palatal vault shapes on linear dimensional change and effect of palatal vault shapes on linear dimensional changes of non-reinforced and fiber reinforced high impact denture base acrylic resin Material and method: Three different palatal vault shapes were prepared on standard casts using CNC (computer numerical control) machine. 60 samples of heat polymerized high impact acrylic resin maxillary denture base were fabri

... Show More
View Publication Preview PDF
Publication Date
Thu Jan 01 2015
Journal Name
Ibn Al-haitham J. For Pure & Appl. Sci.
Synthesis and Characterization of Some Metal Complexes of [N-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol- 4-ylcarbamothioyl) acetamide]
...Show More Authors

A new ligand [N- (1,5- dimethyl -3- oxo- 2 – phenyl - 2 ,3 – dihydro -1H- pyrazol -4- ylcarbamothioyl) acetamide] (AAD) was synthesized by reaction of acetyl isothiocyanate with 4-aminoantipyrine, The ligand was characterized by micro elemental analysis C.H.N.S., FT-IR ,UV-Vis and 1H-13CNMR spectra, some transition metals complex of this ligand were prepared and characterized by FT-IR, UV-Vis spectra, conductivity measurements, magnetic susceptibility and atomic absorption. From the obtained results the molecular formula of all prepared complexes were [M(AAD)2(H2O)2]Cl2 (M+2 = Mn, Co, Ni, Cu, Zn, Cd and Hg),the proposed geometrical structure for all complexes were octahedral.

Publication Date
Sun May 17 2026
Journal Name
Journal Of Baghdad College Of Dentistry
Effect of different palatal vault shapes and woven glass fiber reinforcement on dimensional stability of high impact acrylic denture base [Part I]
...Show More Authors

Background: Change in palatal vault shape and Reinforcement of high impact acrylic denture base resin may in turn affect the dimensional accuracy of acrylic resin and affecting the fitness of the denture.This study evaluated tostudy the effect of fiber reinforcement for high-impact acrylic resin denture base with different palatal vault shapes on adaptation or gap space between the denture base and the stone cast and compare with non-fiber reinforcement and effect of palatal vault shapes on adaptation of non-reinforced and fiber reinforced high impact denture base acrylic resin Material and method: Three different palatal vault shapes were prepared on standard casts using CNC (computer numerical control) machine. 60 samples of heat polymeri

... Show More
View Publication Preview PDF
Publication Date
Sat Jul 01 2023
Journal Name
Journal Of Medicinal And Chemical Sciences
Synthesis, Characterization, and Biological Activity of New Metal Ion Complexes with Schiff Base (Z)-3((E)-2-Hydroxybenzylidene) Hydrazineylidene) Indolin-2-One
...Show More Authors

The study involved preparing a new compound by combining between 2-hydroxybenzaldehyde and (Z)-3-hydrazineylideneindolin-2-one resulting in Schiff bases and metal ions: Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) forming stable minerals-based-Schiff complexes. The formation of resulting Schiff bases is detected spectrally using LC-Mss which gave corresponding results with theoretical results, 1H-NMR proves the founding of N=CH signal, FT-IR indicates the occurrence of imine band and UV-VIs mean is proved the ligand formation. On the other hand, minerals-based-Schiff was characterized using the same spectral means that relied with ligand (Schiff bases). Those means gave satisfactory results and proved the suggested distinguishable geometries.

... Show More
Publication Date
Sat Sep 28 2024
Journal Name
Journal Of The Pakistan Medical Association
Pulse transmission time and amplitude of digital pulse wave determined by fingertip plethysmography as a surrogate marker of brachial artery flowmediated dilatation
...Show More Authors

Objectives: To assess the changes in blood vessel stiffness and digital pulse wave amplitude because of flowmediateddilatation, and to explore how these two variables change when endothelial dysfunction isexperimentally induced.Method: The experimental study was conducted at the departments of physiology at the College of Medicine,Mustansiriyah University, and the College of Medicine, Al-Iraqia University, Baghdad, Iraq, from October 14, 2021, toMay 31, 2022, and comprised healthy young males who were subjected to the flow-mediated dilatation techniqueon the left brachial artery. Pulse transit time and the amplitude of the digital pulse wave were measured duringreactive hyperaemia for 2.5 minutes from the left middle finger using a

... Show More
View Publication Preview PDF
Scopus (1)
Scopus Clarivate Crossref
Publication Date
Thu Jul 14 2022
Journal Name
Egyptian Journal Of Medical Human Genetics
A single-nucleotide polymorphism of IL12A gene (rs582537 A/C/G) and susceptibility to chronic hepatitis B virus infection among Iraqi patients
...Show More Authors

A case–control study (80 patients with chronic hepatitis B virus [HBV] infection and 96 controls) was performed to evaluate the association of an IL12A gene variant (rs582537 A/C/G) with HBV infection. Allele G showed a signifcantly lower frequency in patients compared to controls (31.2 vs. 46.9%; probability [p]=0.009; corrected p [pc]=0.027) and was associated with a lower risk of HBV infection (odds ratio [OR]=0.49; 95% confdence interval [CI]=0.29–0.83). A similar lower risk was associated with genotypes CG (17.5 vs. 29.2; OR=0.25; 95% CI=0.08–0.81; p=0.02) and GG (10.0 vs. 16.7; OR=0.25; 95% CI=0.07–0.91; p=0.036), but the pc value was not signifcant (0.12 and 0.126, respec‑ tively). Serum IL35 levels showed signifcant difere

... Show More
Publication Date
Sun May 17 2026
Journal Name
Journal Of Baghdad College Of Dentistry
Evaluation of shear bond strength of artificial teeth to heat cure acrylic and high impact heat cure acrylic using autoclave processing method
...Show More Authors

Background: Debonding and fracture of artificial teeth from denture bases are common clinical problem, bonding of artificial teeth to heat cure acrylic and high impact heat cure acrylic denture base materials with autoclave processing method is not well known. The aim of this study was to evaluate the effect of autoclave processing method on shear bond of artificial teeth to heat cure denture base material and high impact heat cure denture base material. Materials and methods: Heat polymerized (Vertex) and high impact acrylic (Vertex) acrylic resins were used. Teeth were processed to each of the denture base materials after the application of different surface treatments. The sample (which consist of artificial tooth attached to the dentur

... Show More
View Publication Preview PDF
Publication Date
Mon Sep 23 2024
Journal Name
European Journal Of Orthodontics
Poly-Ether-Ether-Ketone versus dead-soft coaxial bonded retainers: a randomized clinical trial. Part 2: periodontal health and microbial biofilm assessment
...Show More Authors
Abstract<sec> <title>Background

Retainers have the potential to detrimentally impact periodontal health and contribute to tooth decay.

Objectives

To investigate periodontal health and bacterial biofilm related to Poly-Ether-Ether-Ketone (PEEK) fixed retainers as compared to Dead-soft coaxial fixed retainer (DSC).

Trial design

A two-arm parallel groups single-centre randomized c

... Show More
View Publication
Scopus (2)
Crossref (1)
Scopus Clarivate Crossref
Publication Date
Sat May 01 2021
Journal Name
Journal Of Physics: Conference Series
Metal Complexes of Multidentate N<sub>2</sub>S<sub>2</sub> Heterocyclic Schiff-base Ligands;Formation, Structural Characterisation and Biological Activity
...Show More Authors
Abstract<p>The synthesis of ligands with N<sub>2</sub>S<sub>2</sub> donor sets that include imine, an amide, thioether, thiolate moieties and their metal complexes were achieved. The new Schiff-base ligands; N-(2-((2,4-diphenyl-3-azabicyclo[3.3.1]nonan-9-ylidene)amino)ethyl)-2-((2-mercaptoethyl)thio)-acetamide (H<sub>2</sub>L<sup>1</sup>) and N-(2-((2,4-di-p-tolyl-3-azabicyclo[3.3.1]nonan-9-ylidene)amino)ethyl)-2-((2-mercaptoethyl)thio) acetamide (H2L<sup>2</sup>) were obtained from the reaction of amine precursors with 1,4-dithian-2-one in the presence of triethylamine as a base in the CHCl3 medium. Complexes of the general formula K<sub>2<</sub></p> ... Show More
View Publication
Scopus (12)
Crossref (4)
Scopus Crossref