Preferred Language
Articles
/
ijs-4864
Fabrication and Characterization of High-Performance Crosslinked PVA/ PMDA Doped with H2SO4
...Show More Authors

     In the present study, pure Poly(viny1 alcohol) (PVA) and  pyromellitic dianhydride (PMDA) cross linked PVA with (0,5,10,15 and 20)wt.% and doped with different molarity (5,9)M of sulfuric acid (H2SO4) were prepared by the solution casting method and were characterized as a function of  frequency in the range (1-100) KHz.

     The FT-IR results showed that the strong broad band observed at 3738.05 and 3857.63 cm-1 may be assigned to O-H stretching due to the strong hydrogen bond of intramolecular and intermolecular type in PVA film.  When PVA is doped with 5M and 9M H2SO4,  a new peak was noticed at 813 cm-1, this peak may be due to the formation of hydrogen bond between the carbonyl (C=O) group of PVA and the H+ ion from the acid.

      As the PMDA concentration increases, the peak intensity of the O–H band 3738.05 cm−1 gradually decreases due to the reaction of more –OH groups of the PVA molecules with the –COOH group. Hence, it is difficult for the crosslinked PVA polymer chains to pack and form crystal regions, so the crosslinked PVA polymer chains become more flexible.

        The a.c. conductivity increases with the increase of frequency. FTIR spectra specified that the chemical reaction did occur between the PVA and the acid, therefore  hydrogen ion (H+) can easily be  separated from the carbonyl group and become free to move which explains proton conductivity of PVA.

    The increase of PMDA concentration has increased free volume and ionic mobility in the film with increasing cross-linkages.

     Dielectric constant decreases with increasing H2SO4 molarity for every frequency.

Scopus Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Thu Jun 30 2011
Journal Name
Al-khwarizmi Engineering Journal
Characterization of Delamination Effect on Free Vibration of Composite Laminates Plate Using High Order Shear Deformation Theory
...Show More Authors

 A dynamic analysis method has been developed to investigate and characterize embedded delamination on the dynamic response of composite laminated structures. A nonlinear finite element model for geometrically large amplitude free vibration intact plate and delamination plate analysis is presented using higher order shear deformation theory where the nonlinearity was introduced  in the Green-Lagrange sense. The governing equation of the vibrated plate were derived using the Variational approach. The effect of different orthotropicity ratio, boundary condition and delamination size on the non-dimenational fundamental frequency and frequency ratios of plate for different stacking sequences are studied. Finally th

... Show More
View Publication Preview PDF
Publication Date
Fri Jul 03 2020
Journal Name
Agriculture
Potato Phosphorus Response in Soils with High Value of Phosphorus
...Show More Authors

Phosphorus (P) is an element that is potatoes require in large amounts. Soil pH is a crucial factor impacting phosphorus availability in potato production. This study was conducted to evaluate the influence of P application rates on the P efficiency for tuber yield, specific gravity, and P uptake. Additionally, the relationship between soil pH and total potato tuber yield was determined. Six rates of P fertilization (0–280 kg P ha−1) were applied at twelve different sites across Northern Maine. Yield parameters were not responsive to P application rates. However, regression analysis showed that soil pH was significantly correlated with total potato tuber yield(R2 = 0.38). Sites with soil pH values < 6 had total tuber yields,

... Show More
View Publication
Crossref (21)
Crossref
Publication Date
Sun Mar 04 2018
Journal Name
Iraqi Journal Of Science
the Polymer optical fiber sensor side-pumped with polymer clad doped lasing compounds
...Show More Authors

Optical fibers were produced by the system manufactured for this purpose and then, PMMA core of polymer optical fiber (POF) and PMMA doped Rhodamine B (RhB) claddings were studied and determine their UV–vis absorption and emission. The study adopted the mechanism of lateral pumping of the product polymer optical fiber by using laser with 404 nm excitation to study optical specifications of the factory fiber. It was noted that there were blue shift in maximum peak wavelength in absorption and fluorescence from the doped polymer before use it as clad. The obtained results by using the doping polymer with (RhB) for clad the amplified spontaneous emission ASE seems in fluorescence study. The side excitation shows that there were no an over

... Show More
View Publication Preview PDF
Publication Date
Wed Jul 29 2020
Journal Name
Iraqi Journal Of Science
High AdiponectinHormone Modulation ofBlood Erythroid Parameters and its Relation with Erythropoietin in Patients with Diabetic Nephropathy
...Show More Authors

Background: Serum adiponectin is a hormone of adipose tissue that activateslipid metabolism and exertsphysiological functions. Its level usually fluctuates in several metabolic diseases,including renal insufficiency and diabetes; it loses its protective role against diseases and becomes a potentially risk factor for erythroid abnormalities.

Objectives: The study was designed to assess the association between adiponectin  hormone, blood erythroid and various parameters in groups of patients.

Method:The study included 130 patientsand 42 healthy subjects. Parameters of serum adiponectin, erythropoietin (EPO), red blood cells (RBC), hemoglobin (Hb), hematocrit (Hct), ren

... Show More
View Publication Preview PDF
Scopus Crossref
Publication Date
Wed Mar 01 2017
Journal Name
Nano Hybrids And Composites
Synthesis of ZnS QDs with Different Values of pH and White Light Generation from Fabrication of TPD: PMMA/ZnS Hybrid Devices
...Show More Authors

Quantum dots (QDs) of zinc sulfide (ZnS) was prepared by chemical reaction with different potential of hydrogen (pH) and used to fabricate organic quantum dot hybrid junction device. The optical properties of QDs were characterized by ultraviolet-visible (UV-Vis.) and photoluminescence (PL) spectrometer. The results show that the prepared QDs were nanocrystalline with defects formation. The energy gap (Eg)calculated from PL were 3.64, 3.53 and 3.35 eV for pH=8, 10 and 12 respectively. This decreasing of energy gaps is results of the effect the pH solution increases, which in turn leads to the shifted of the PL spectrum toward red shifted, which makes the energy bands at surface states are shallow ban

... Show More
View Publication
Crossref (3)
Crossref
Publication Date
Tue Apr 09 2013
Journal Name
Chemistry And Materials Research
Hydrogen Bonds Effects on the Electrical Properties of Pectin/Pva Graphene Nanocomposites
...Show More Authors

Electrical properties were studied for Pectin/PVA graphene composites films and the effect of aqueous interaction on their properties. The conductivity and the dielectric constant of this composite are important because Polysaccharide like pectin is increasingly being used in biomedical applications and as nanoparticles coating materials. The Dielectric and conductivity of composite films were compared in dry and wet condition the differences in the results were attributed to the water molecules and the hydrogen bond which connect the three composite compounds (Pectin, PVA and Graphene) together. These connections were allowed the hydrogen and hydroxyl group’s migrations in the composite super molecules. On the other hand, graphene was pr

... Show More
Preview PDF
Publication Date
Fri Jan 11 2019
Journal Name
Iraqi Journal Of Physics
Study of starch, sugar blending effect on the biodegradability of (PVA) for packaging applications
...Show More Authors

PVA, Starch/PVA, and Starch/PVA/sugar samples of different
concentrations (10, 20, 30 and 40 % wt/wt) were prepared by casting
method. DSC analysis was carried; the results showed only one glass
transition temperature (Tg) for the samples involved, which suggest
that starch/PVA and starch/PVA/sugar blends are miscible. The
miscibility is attributed to the hydrogen bonds between PVA and
starch. This is in a good agreement with (FTIR) results. Tg and Tm
decrease with starch and sugar content compared with that for
(PVA). Systematic decrease in ultimate strength, due to starch and
sugar ratio increase, is attributed to (PVA), which has more hydroxyl
groups that made its ultimate strength higher than that for

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Thu Mar 25 1993
Journal Name
كلية العلوم. / جامعة بغداد
ISOLATION AND CHARACTERIZATION OF EXTREMELY HALOPHILIC BACTERIA FROM SADDAM RIVER REGIONS AND THE RULE OF MEMBRANE PROTEINS IN THE RESISTANCE TO HIGH SALINITY
...Show More Authors

This study included isolation and characterization of extremely halophilic bacteria from Al-Massab Al-Aam region in South of Iraq Fifty isolates were identified by using numerical taxonomy 40 strains belonged to the genus Halobacterium which inclucted Hb. halobium Hb. cutirubrum Hb. salinarium Hb. saccharovorum Hb. valismortis and Hb. volcanii. Ten strains belonged to the genus Halococcus which included Hc. morrhuae Hc. saccharolyticus. Growth curves were sensitive mutants determined for wild type and salt Generation time in logarthmic phase was measured and found to be (10.37 2hr 7 0.59) for Hb. salinarium / 18 (6.490 hr 0.24) for Hb. cutirubrum / 32, (6.700 hr + 0.488) for Hb. valismortis / 20, (11.243 hr + 0.96) for Hb. volcanii / 7. (7

... Show More
Publication Date
Thu Apr 29 2021
Journal Name
Egyptian Journal Of Chemistry
Fabrication and Study of ZnO thin Films using Thermal Evaporation Technique
...Show More Authors

Pure SnSe thin film and doped with S at different percentage (0,3,5,7)% were deposited from alloy by thermal evaporation technique on glass substrate at room temperature with 400±20nm thickness .The influences of S dopant ratio on characterization of SnSe thin film Nano crystalline was investigated by using Atomic force microscopy(AFM), X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), Hall Effect measurement, UV-Vis absorption spectroscopy to study morphological, structural, electrical and optical properties respectively .The XRD showed that all the films have polycrystalline in nature with orthorhombic structure, with preferred orientation along (111)plane .These films was manufactured of very fine crystalline size in the ra

... Show More
View Publication
Scopus (1)
Scopus Clarivate Crossref
Publication Date
Thu Jun 15 2023
Journal Name
International Journal Of Nanoscience
Fabrication and Enhancement of Organic Photodetectors Based on Iron Phthalocyanine Films
...Show More Authors

Iron–phthalocyanine (FePc) organic photoconductive detector was fabricated using pulsed laser deposition (PLD) technique to work in ultraviolet (UV) and visible regions. The organic semiconductor material (iron phthalocyanine) was deposited on n-type silicon wafer (Si) substrates at different thicknesses (100, 200 and 300) nm. FePc organic photoconductive detector has been improved by two methods: the first is to manufacture the detector on PSi substrates, and the second is by coating the detector with polyamide–nylon polymer to enhance the photoconductivity of the FePc detector. The current–voltage (I–V) characteristics, responsivity, photocurrent gain, response time and the quantum efficiency of the fabricated photoconduc

... Show More
View Publication
Scopus (1)
Crossref (1)
Scopus Clarivate Crossref