Preferred Language
Articles
/
jih-62
Mesomorphic and Dielectric Properties of Heterocyclic Liquid Crystals with Different Terminal Groups
...Show More Authors

  A new hetrocyclic liquid crystal compounds containing 1,3,4-oxadiazole with different substituted in para position (Bromo, Chloro, Nitro and Methyl) were synthesized and characterized by melting points, FTIR Spectroscopy and 1HNMR spectroscopy for [Cl-SR6] and [NO2-SR6] compounds. The liquid crystalline properties of the synthesized compounds were studied by using hot-stage polarizing optical microscopy (POM), so they determined the transition enthalpies and entropies by using differential scanning calorimetery (DSC). All of the compounds show mesomorphic properties. The compounds [Br-SR6], [Cl-SR6] and [NO2SR6] exhibit an enantiotropic dimorphism smectic (Sm) phase, while the compounds [MeSR6] showed nematic (N) phase throw cooling only. Continuously, permittivity dielectric properties, electrical conductivity, relaxation times and activation energies have been studied in the range of temperatures (70-150)°C at two frequencies (500) Hz and (1000) Hz. Generally, the results show the dielectric permittivity and relaxation time values increasing when raising temperature, while electrical conductivity values decrease with increasing temperature. The activation energy values were determined in terms of the Arrhenius plot.         

View Publication Preview PDF
Quick Preview PDF
Publication Date
Fri Jan 19 2018
Journal Name
Journal Of Global Pharma Technology
Synthesis, Characterization and Study of Electrical Properties of Some New Aromatic Polyester
...Show More Authors

This research discloses the synthesis of various polyester resins, the polyesters containing homoring aromatic and others heterocyclic were synthesized by the condensation polymerization of suitable monomers (which are containing variety function groups in different structures) with phthalic anhydride. The main objective is synthesis of new polyester with keeping a reasonable electrical insulating behavior. The structural of polymer was characterized by Fourier Transform infra-red spectroscopy FTIR and HNMR. The dielectric constant (real ε' and imaginary parts ε") and AC conductivity (σAC) for all the polyester samples are studied by varying the frequency (30, 50, 70, 90, 120, 300, 500Hz and 1KHZ) at 25⁰ C. Indeed, study of the electri

... Show More
Publication Date
Wed Mar 10 2021
Journal Name
Baghdad Science Journal
Some properties of bismuth glass solubility visual containing 15% of zinc oxide Mall with concentrated phosphoric acid
...Show More Authors

Conducted the study of the experimental conditions of the interaction of glass the visual Alpmuth containing 15% Mall of zinc with phosphoric acid ????? various degrees of thermal and clip areas prone to interact different way turntable

View Publication Preview PDF
Publication Date
Wed Jan 01 2020
Journal Name
Biochemical And Cellular Archives
EVALUATION OF WATER STRESS EFFECT ON SOME CHEMICAL PROPERTIES OF SEVERAL SUNFLOWER VARIETIES CALLUS TREATED WITH ULTRAVIOLET
...Show More Authors

The study was carried out in plant tissue culture laboratory, University of Baghdad during the period 2017-2019, as factorial experiment in complete randomized design, to study the effect of PEG at (0, 2, 4, 6 and 8%) on physiological and chemical changes in callus of three sunflower (Ishaqi 1, Aqmar and Al-haga) induced by the cultivation of the young stem in vitro under water stress. The content of callus cells of SOD, POD, CAT and APX enzymes as well as content of hydrogen peroxide were determined as indicators to determine the effect of PEG in callus tissue cells cultivated on medium equipped with the PEG concentrations. The results showed that cultivars were differs significantly and Al-hajavariety was superior in increasing SOD to 24.

... Show More
Scopus (3)
Scopus
Publication Date
Sat Oct 18 2025
Journal Name
Journal Of Baghdad College Of Dentistry
Elevation in surface temperature of root canals obturated with different thermoplasticized gutta-percha obturation techniques-an in vitro study
...Show More Authors

Background: Many studies have been conducted to evaluate the effect of using a hot material in the root canal and its potential for causing damage to the tooth supporting structure. Materials and methods: thirty permanent premolars were obturated with thermoplasticized Gutta-Percha using three different obturation techniques: soft core, Thermafil, and obtura to evaluate the rise in temperature on the root surface using a multipurpose digital thermometer. Results: temperature increases was significantly greater for Obtura versus Soft core (p<0.003), not significant for Thermafil versus Soft core (p<0.087), and Thermafil versus Obtura (p<0.125). Conclusions: temperatures rise on the root surface were below the critical level and, therefore, s

... Show More
View Publication Preview PDF
Publication Date
Mon Sep 01 2025
Journal Name
Journal Of Oral Biology And Craniofacial Research
Morphological &amp; chemo mechanical analysis of exposed cervical dentin treated with three different desensitizing pastes (comparative in vitro study)
...Show More Authors

Background Obstructing dentinal tubules is a valuable approach for managing dentin hypersensitivity. Although various agents promote dentin remineralization, direct comparisons between theobromine, bioactive glass (BAG), and nano-hydroxyapatite (Nano-HAP) under simulated oral conditions remain limited. To fill this gap, this in vitro study aimed to evaluate and compare the effectiveness of these three treatments on exposed cervical dentin. The assessment focused on their chemical, morphological, and mechanical effects on dentin. Materials and methods Forty-eight human dentin slabs were obtained from the cervical portions of twelve sound premolar teeth. Baseline Raman spectroscopy and VMH tests were done to exclude outliers. All specimens we

... Show More
View Publication
Scopus Crossref
Publication Date
Thu Dec 06 2018
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Comparing the Quality of Life among Patients with Relapsing Remitting Multiple Sclerosis in Iraq Using Different Disease Modifying Therapies
...Show More Authors

Multiple sclerosis (MS) is a chronic, inflammatory, immune mediated disease of the central nervous system, mostly affecting young adults with mean age of 30 years, twice as high in women compared to men. The etiology of MS is not fully elucidated. MS symptoms are directly related to demyelination and axonal loss, along with other psychological symptoms, can result in functional limitations, disability and reduced quality of life (QoL).  The QoL assessments in patients with a chronic disease may contribute to improving treatment and could even be of prognostic value. The goals  of this study were  to  compare the QoL of  Iraqi patients with relapsing remitting multiple sclerosis (RRMS),using three different diseas

... Show More
View Publication Preview PDF
Scopus (7)
Scopus Crossref
Publication Date
Thu Jan 27 2022
Journal Name
Nanomaterials
Improving the Melting Duration of a PV/PCM System Integrated with Different Metal Foam Configurations for Thermal Energy Management
...Show More Authors

The melting duration in the photovoltaic/phase-change material (PV/PCM) system is a crucial parameter for thermal energy management such that its improvement can realize better energy management in respect to thermal storage capabilities, thermal conditions, and the lifespan of PV modules. An innovative and efficient technique for improving the melting duration is the inclusion of an exterior metal foam layer in the PV/PCM system. For detailed investigations of utilizing different metal foam configurations in terms of their convective heat transfer coefficients, the present paper proposes a newly developed mathematical model for the PV/PCM–metal foam assembly that can readily be implemented with a wide range of operating condition

... Show More
View Publication
Scopus (33)
Crossref (34)
Scopus Clarivate Crossref
Publication Date
Wed Mar 08 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Electrical Insulation Breakdown Strength and Thermal Conductivity of Different Blended Nanocomposites of New Epoxy Resins
...Show More Authors

This research studies the development and synthesis of blended nanocomposites filled with Titanium dioxide (TiO2). Blended nanocomposites based on unsaturated polyester resin (UPR) and epoxy resins were synthesized by reactive blending. The optimum quantity from nano partical of titanium dioxide was selected and different weight proportions 1%, 3%, 5%, and 7% ratios of new epoxy are blended with UPR resin. The dielectric breakdown strength and thermal conductivity properties of the blended nanocomposites were compared with those of the basis material (UPR and 3% TiO2).The results show good compatibility epoxy resins with the UPR resin on blending, dielectric breakdown strength values  are higher while thermal conductivity values of

... Show More
View Publication
Publication Date
Fri May 01 2020
Journal Name
Applied Thermal Engineering
Thermal performance of a flat-plate solar collector using aqueous colloidal dispersions of graphene nanoplatelets with different specific surface areas
...Show More Authors

The effects of using aqueous nanofluids containing covalently functionalized graphene nanoplatelets with triethanolamine (TEA-GNPs) as novel working fluids on the thermal performance of a flat-plate solar collector (FPSC) have been investigated. Water-based nanofluids with weight concentrations of 0.025%, 0.05%, 0.075%, and 0.1% of TEA-GNPs with specific surface areas of 300, 500, and 750 m2/g were prepared. An experimental setup was designed and built and a simulation program using MATLAB was developed. Experimental tests were performed using inlet fluid temperatures of 30, 40, and 50 °C; flow rates of 0.6, 1.0, and 1.4 kg/min; and heat flux intensities of 600, 800, and 1000 W/m2. The FPSC’s efficiency increased as the flow rate and hea

... Show More
Crossref (42)
Crossref
Publication Date
Sat Jan 30 2016
Journal Name
Ibn Al-haitham J. For Pure & Appl. Sci.
Study of Some Structural and Optical Properties of AgAlSe2 Thin Films
...Show More Authors

The structural properties of ternary chalcopyrite AgAlSe2 compound alloys and thin films that prepared by the thermal evaporation method at room temperature on glass substrate with a deposition rate (5±0.1) nm s-1 for different values of thickness (250,500 and 750±20) nm, have been studied, using X-ray diffraction technology. As well as, the optical properties of the prepared films have been investigated. The structural investigated shows that the alloy has polycrystalline structure of tetragonal type with preferential orientation (112), while the films have amorphous structure. Optical measurement shows that AgAlSe2 films have high absorption in the range of wavelength (350-700 nm). The optical energy gap for allowed direct transition we

... Show More
Preview PDF