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Improving the Dielectric, Thermal, and Electrical Properties of Poly (Methyl Methacrylate)/Hydroxyapatite Blends by Incorporating Graphene Nanoplatelets
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In this article, the casting method was used to prepare poly(methyl methacrylate)/hydroxyapatite (PMMA/HA) nanocomposite films incorporated with different contents (0.5, 1, and 1.5 wt%) of graphene nanoplatelets (Gnp). The chemical properties and surface morphology of the PMMA/HA blend and PMMA/HA/Gnp nanocomposite were characterized using FTIR, and SEM analysis. Besides, the thermal conductivity, dielectric and electrical properties at (1–107 Hz) of the PMMA/HA blend and PMMA/HA/Gnp composites were investigated. The structural analysis showed that the synthesized composites had a low agglomerated state, with multiple wrinkles of graphene flakes in the PMMA/HA blend. The thermal conductivity was improved by more than 35-fold its value for pure PMMA. The AC and DC electrical conductivities of PMMA/HA/Gnp composites were enhanced with increasing the amount of Gnp and the estimated exponent (s) being between 1.25 and 1.3. The values of the real part (ɛ′) and imaginary part (ε′′) of the dielectric constant as well as electrical impedance depend on the Gnp ratio. The value of ɛ′ was reduced at the lower frequency (< 105 Hz) and became constant at the higher frequency which attributed to the relaxation time. The values of ε″ are small at low frequencies and increase with increased frequency due to the electronic polarization effects as well as to the dipoles not beginning to follow the field variation at higher frequencies. The increase in the dielectric loss, tan(δ), with an increase in Gnp content, to 0.5 wt%, due to the interfacial polarization mechanism occurred in the composite’s films corresponding to frequencies

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Publication Date
Sat Jul 01 2023
Journal Name
Journal Of Engineering
Independent Thermal Network Through Thermal Synergy Between Four Architectural Units
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The manifestations of climate change are increasing with the days: sudden rains and floods, lakes that evaporate, rivers that experience unprecedentedly low water levels, and successive droughts such as the Tigris, Euphrates, Rhine, and Lape rivers. At the same time, energy consumption is increasing, and there is no way to stop the warming of the Earth's atmosphere despite the many conferences and growing interest in environmental problems. An aspect that has not received sufficient attention is the tremendous heat produced by human activities. This work links four elements in the built environment that are known for their high energy consumption (houses, supermarkets, greenhouses, and asphalt roads) according t

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Publication Date
Thu Dec 31 2015
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Density, Viscosity and Refractive Index of the Ternary System (Ethanol + N-Hexane +3-Methyl Pentane) at 20, 30, 40 °C and 101.325 Kpa
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Experimental densities, viscosities η, and refractive indices nD data of the ternary  ethanol+ n-hexane + 3-methyl pentane system have been determined at temperatures 293.15,303.15 and 313.15 K and at atmospheric pressure then these properties were calculated theoretically by using mixing rules for densities, viscosities and refractive indices .After that the theoretical data and the experimental data were compared due to the high relative errors in viscosities an equation of viscosity was proposed to decrease the relative errors.

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Publication Date
Sat Sep 01 2012
Journal Name
Journal Of Economics And Administrative Sciences
Testing the Assumption of Linearity for Sales of State Company for Electrical Industries
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In this study, the four tests employed for non-linear dependence which is Engle (1982), McLeod &Li (1983), Tsay (1986), and Hinich & Patterson (1995). To test the null hypothesis that the time series is a serially independent and identical distribution process .The linear structure is removed from the data which is represent the sales of State Company for Electrical Industries, through a pre-whitening model, AR (p) model .From The results for tests to the data is not so clear.

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Publication Date
Tue May 01 2018
Journal Name
Journal Of Physics: Conference Series
The partial substitution of copper with nickel oxide on the Structural and electrical properties of HgBa<sub>2</sub> Ca<sub>2</sub> Cu<sub>3x</sub>Ni<sub>x</sub> O<sub>8+δ</sub> superconducting compound
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Publication Date
Fri Jul 01 2016
Journal Name
Journal Of Engineering And Sustainable Development
EVALUATION OF MECHANICAL PROPERTIES OF HIGH PERFORMANCE SELF-CONSOLIDATED CONCRETE ENHANCED BY DISCRETE STEEL AND POLYPROPYLENE FIBERS
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High performance self-consolidating concrete HP-SCC is one of the most complex types of concrete which have the capacity to consolidated under its own weight, have excellent homogeneity and high durability. This study aims to focus on the possibility of using industrial by-products like Silica fumes SF in the preparation of HP-SCC enhanced with discrete steel fibers (DSF) and monofilament polypropylene fibers (PPF). From experimental results, it was found that using DSF with volume fraction of 0.50 %; a highly improvements were gained in the mechanical properties of HP-SCC. The compressive strength, splitting tensile strength, flexural strength and elastic modulus improved about 65.7 %, 70.5 %, 41.7 % and 80.3 % at 28 days age, respectively

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Publication Date
Tue Jun 30 2020
Journal Name
Journal Of Economics And Administrative Sciences
Organizational culture and its role in improving the quality of educational service at the university center Tindouf from the perspective of professors.
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This paper examines the impact of the organizational culture prevailing at the university center, Ali KafiTindouf, on the quality of the educational service provided by the university center Ali KafiTindouf from the point of view of the teachers of the center. The questionnaire method was used to determine the effect between the variables studied, by the distribution of 33 questionnaires on a random sample of the study community.

The study found that the organizational culture prevailing at the university center of Ali KafiTindouf contributed to reaching higher levels in the awareness and quality of the educational service provided by the teachers of the center.<

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Publication Date
Sun Feb 10 2019
Journal Name
Iraqi Journal Of Physics
Electrical and morphological study of thermally evaporated (Sb2S3)1-xSnx thin films
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(Sb2S3)1-xSnx thin films with different concentrations (0, 0.05 and
0.15) and thicknesses (300,500 and 700nm) have been deposited by
single source vacuum thermal evaporation onto glass substrates at
ambient temperature to study the effect of tin content, thickness and
on its structural morphology, and electrical properties. AFM study
revealed that microstructure parameters such as crystallite size, and
roughness found to depend upon deposition conditions. The DC
conductivity of the vacuum evaporated (Sb2S3)1-x Snx thin films was
measured in the temperature range (293-473)K and was found to
increase on order of magnitude with

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Publication Date
Tue Dec 31 2019
Journal Name
Journal Of Economics And Administrative Sciences
Measuring the Range Application of Internal Marketing for HRM Philosophy in the Public Company for Electrical and Electronic Industries
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The reason behind choosing this topic " internal marketing (IM) of human resource management (HRM)" is to highlight the advantages of using IM in the organization framework. The problem of the research paper lies in not paying enough attention to employees genuine needs as they interact with each other in the sake of organization prosper. This research paper can be used as indictor to expose the weaknesses that the organization encounters daily. The current research paper attempts at examining the possibility of developing philosophy of internal marketing of human resources and its most practices, empowering staff, training courses, motivations and recognitions, and within departments communication, in order to reach targeted res

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Publication Date
Sun Feb 10 2019
Journal Name
Iraqi Journal Of Physics
The role of atmospheric non-thermal plasma in the bacteria inactivation
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Non-thermal atmospheric pressure plasma has emerged as a
new promising tool in medicine and biology. In this work, A DBD
system was built as a source of atmospheric pressure non-thermal
Plasma suitable for clinical and biological applications. E. coli and
staphylococcus spp bacteria were exposed to the DBD plasma for a
period of time as inactivation (sterilization) process. A series of
experiments were achieved under different operating conditions. The
results showed that the inactivation, of the two kinds of bacteria, was
affected (increasing or decreasing) according to operation conditions
because they affects, as expected, the produced plasma properties
according to those conditions.

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Crossref
Publication Date
Tue Sep 01 2015
Journal Name
Journal Of Engineering
Experimental Study on the Effect of Using Metallic Brushes on the Charging and Discharging Time of Thermal Energy Storage Unit
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Phase change materials are known to be good in use in latent heat thermal energy storage (LHTES) systems, but one of their drawbacks is the slow melting and solidification processes. So that, in this work, enhancing heat transfer of phase change material is studied experimentally for in charging and discharging processes by the addition of high thermal conductive material such as copper in the form of brushes, which were added in both PCM and air sides. The additions of brushes have been carried out with different void fractions (97%, 94% and 90%) and the effect of four different air velocities was tested. The results indicate that the minimum brush void fraction gave the maximum heat transfer in PCM and reduced the time

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