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ijs-2871
UV-Exposure effect on the mechanical properties of PEO/PVA blends
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     Poly ethylene oxide PEO / Poly vinyl alcohol PVA  blends were prepared by cast method at different ratios of (25%PEO/75%PVA, 30%PEO/70%PVA, 35%PEO/65%PVA, 40%PEO/60%PVA, and 50%PEO/505PVA). Samples miscibility ,and thermal stability were studied  by using differential scanning calorimetry(DSC),and thermo gravimetric analysis (TGA) analysis. The results proved that there was one glass transition temperature (Tg=160°C) at 25%PEO\PVA ratio
)that was attributed to its miscibility. This miscibility associated with (Hydrogen  bonds) between (Hydroxyl group) in PVA, and PEO, whereas there were two glass transition temperature for the blends ratio more than 30%PEO,that was due its immiscibility. The results proved increase in glass transition temperature (Tg) with PEO loading increase: whereas the melting point was fixed about(Tm=310°C). TGA results showed that  PEO loading caused overlapping between degradation stages ,and shifting in the second stage to higher degradation temperature, that was due to the good  PVA, and PEO compatibility, and thermal  stability improved of polymer blends. The mechanical properties of the samples  involved were studied :it was found  that  the tensile strength decreased with PEO ratio increase: whereas ,the elongation at break increased  with PEO ratio . 25% PEO/PVA proved  better tensile strength than the others blend ratios and elongation-at-break values in comparison with that ratio more than 25%,which was due  to good miscibility. These results were enhanced with optical microscope and FTIR analysis. 25%PEO/PVA was sellected to  study the UV-Weathering effect on the mechanical properties according to its ultimate strength(26.67MPa) in comparision with the blends envolved.The stress strain curves for 25%PEO/PVA before and after UV-Weathering with periods of time(25,60,and 90Hr.) showed little changes in ultimate strength up  to (60Hr) exposure time,then there were little decrese in ultmate strength in(90Hr) exposure time . Ultimate tensile strength decrease was attributed to premature failur induced by polymer photo degradation. UV-Weathering caused yelowish of  exposed samples that was due to long chain conjugated polymer sequencesbond formation induced by oxidative  photo degradation . The results proved little changes within (60Hr),that was attributed to polymer stability.It was folowed by little changes in tensile strength and   the elongation at break decreased that was due to sample brittlence increase,which was induced  by irradiation ,that caused modulus of elasticity increase. It was experimentally observed that the value of thermal conductivity of (PVA= 0.099W/cm.K).The results proved decrease in thermal conductivity with PEO loading increase.

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Publication Date
Fri Dec 01 2023
Journal Name
Physical Chemistry Research
Thermophysical Study of Ethylene Glycol + H<inf>2</inf>O and Ethylene Glycol + (DMF/H<inf>2</inf>O) at 298.15 K
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n this research, some thermophysical properties of ethylene glycol with water (H2O) and two solvent mixtures dimethylformamide/ water (DMF + H2O) were studied. The densities (ρ) and viscosities (η) of ethylene glycol in water and a mixed solvent dimethylformamide (DMF + H2O) were determined at 298.15 K, t and a range of concentrations from 0.1 to1.0 molar. The ρ and η values were subsequently used to calculate the thermodynamics of mixing including the apparent molar volume (ϕv), partial molar volume (ϕvo) at infinite dilution. The solute-solute interaction is presented by Sv results from the equation ∅_v=ϕ_v^o+S_v √m. The values of viscosity (B) coefficients and Falkenhagen coefficient(A) of the Jone-Dole equation and Gibbs free

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Publication Date
Mon Sep 18 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Light Induced Hydrogen Production From Ethanolic Aqueous Solutions Sensitizzed By 2,4-Dimetboxy Benzylidene-2- Hydroxy Aniline And Some of Its Metal Complexes
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Hydrogen   productions  were  achieved    by  irradiating  ethanol ic aqueous solutions (20%. v/v) containing  mixtures of  the  ligand  2,4- dimethoxybcnzylidene-2-hydroxy    aniline     (HL)     or    one    of     i ts complexes  (ML2)   wi th  the  following  divalent  ions:  fVbl  (II),  Fc(IT), Co(II). Ni( rt ), Cu(H) and  Zn (11), as photosensi1izers, methyl  viol ogen (MY.:-)    as   electron   acceptor.  ethylene    diamine &nbsp

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Publication Date
Wed May 10 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Synthesis, Characterization and Analytical Study of Metal Complexes Derived from 1,2-Bis-(4´-Amino-2´,3´- Dimethyl-1´- Phenyl-Pyrazolinyl)- Diimino Ethane
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       Six transition metal complexes of Cr (III), Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) were prepared using 1,2-bis -(4-Amino-2,3-dimethyl-1- phenyl-pyrazolinyl)-diimino ethane(L) as ligand.  These complexes were characterized by elemental analysis, magnetic susceptibility, UV/VIS and FT-IR spectroscopy. These data showed that the solid complexes of Mn(II), Co(II), Zn(II) were tetrahedral geometry, and Cr(III) was octahedral while the symmetry around  Ni(II) and Cu(II) ions with the new ligand were square planar of the formula [ML]Cl2 ,  M=Ni(II) and Cu(II).        

      A simple method for the determina

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Publication Date
Sun Jan 12 2025
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
Sun Mar 06 2016
Journal Name
Baghdad Science Journal
Comparison Between Conventional and Microwave Methods For Extraction Pectin and Degree of Esterification from Orange (Citrus sinesis) and Grapefruit (Citrus paradisi) Peels
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In this study Microwave and conventional methods have been used to extract and estimate pectin and its degree of esterification from dried grapefruit and orange peels. Acidified solution water with nitric acid in pH (1.5) was used. In conventional method, different temperature degrees for extraction pectin from grape fruit and orange(85 ,90 , 95 and 100?C) for 1 h were used The results showed grapefruit peels contained 12.82, 17.05, 18.47, 15.89% respectively, while the corresponding values were 5.96, 6.74, 7.41 and 8.00 %, respectively in orange peels. In microwave method, times were 90, 100, 110 and 120 seconds. Grapefruit peels contain 13.86, 16.57, 18.69, and 17.87%, respectively, while the corresponding values were of 6.53, 6.68, 7.2

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Publication Date
Tue Nov 30 2021
Journal Name
Iraqi Journal Of Science
Evaluation of Left Ventricle Performance in Patients with Ischemic Heart Disease Using Single Photon Emission Computed Tomography (SPECT) in Comparison with Echocardiography
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Background: Ischemic heart disease is a major cause of the diastolic heart failure. Risk of heart failures was increased with microvascular coronary disease, which is characterized by left ventricular stiffness  with impaired relaxation and reduced compliance. Aim of this study is to estimate the effect of the severity of myocardium ischemia on the left ventricle ejection fraction and left ventricular volume using SPECT with 99mTc MIBI and to compare the results  with the echocardiography. The study included 117 subjects with ischemic heart disease were examined using SPECT and echocardiography techniques. The following

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Publication Date
Mon May 22 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Excess Molar Volumes and Viscosities of Mixtures Containing Dimethylformamide (DMF) with benzene, o-xylene, 1, 4- Dioxane and Tetrahydrofuran at 298.15 K.
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          Measurements of excess molar volumes VE , viscosities η , excess viscosities Δ ln η  and excess molar activation energies of viscous flow ΔGE , are reported for binary mixtures of dimethylformamide (DMF) with , benzene , o-xylene , 1,4- dioxane and tetrahydrofuran are reported from density and viscosity measurements at 298.15 k and at atmospheric pressure over the entire composition range . The excess values are positive for the mixture (DMF+ polar solvent) and negative deviation from ideality for the mixture (DMF + non-polar solvent) over the whole composition range and discussed in the light of molecular interaction in the mixture.

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Publication Date
Tue Sep 08 2020
Journal Name
Baghdad Science Journal
Using Real-Time PCR to Investigate Some of Antibiotic Resistance Genes from Streptococcus agalactiae Isolates from ewe Mastitis cases in Nineveh province
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In this study, from a total of 856 mastitis cases in lactating ewes, only 34 Streptococcus agalactiae isolates showed various types of resistance to three types of antibiotics (Penicillin, Erythromycin and Tetracycline). St. agalactiae isolates were identified according to the standard methods, including a new suggested technique called specific Chromogenic agar. It was found that antibiotic bacterial resistance was clearly identified by using MIC-microplate assay (dilution method). Also, by real-time PCR technique, it was determined that there were three antibiotics genes resistance ( pbp2b, tetO and mefA ). The high percentage of isolate carried of a single gene which was the Tetracycline (20.59%) followed by percentage Penicillin was

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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
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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.

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Publication Date
Thu Jan 12 2017
Journal Name
Journal Of Agricultural And Food Chemistry
Using Standing Gold Nanorod Arrays as Surface-Enhanced Raman Spectroscopy (SERS) Substrates for Detection of Carbaryl Residues in Fruit Juice and Milk
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