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bsj-2993
Acoustic and Thermal Insulation of Nanocomposites for Building Material: Improvement Of Sound And Thermal Insulation Properties Of Nanocomposite
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This work aims to enhance acoustic and thermal insulation properties for polymeric composite by adding nanoclay and rock wool as reinforcement materials with different rations. A polymer blend of (epoxy+ polyester) as matrix materials was used. The Hand lay-up technique was used to manufacture the castings. Epoxy and polyester were mixed at different weight ratios involving (50:50, 60:40, 70:30, 80:20, and 90:10) wt. % of (epoxy: polyester) wt. % respectively. Impact tests for optimum sample (OMR), caustic and thermal insulation tests were performed. Nano clay (Kaolinite) with ratios ( 5 and 7.5% ) wt.% , also hybrid reinforcement materials involving (Kaolite 5 & 7.5 % wt.% + 10% volume fraction of rockwool ) were added as reinforcement materials to the optimum sample. Results of impact test prove that the optimum sample has (80:20) wt. % of mixing ratio of (epoxy: polyester) wt. % for using as matrix materials. Moreover, the adding of nanoclay (Kaolinite) with ratio (7.5 wt.%) leads to the highest sound insulation. The sound intensity started at (99.8) db at 100 Hz, and reached to (101.3) db at 10000 Hz., which is much lower than the values obtained from the un-reinforced blend, of which the sound intensity started at (107.2) db and reached to (108.7) db., at the same range of frequencies. Thermal conductivity results show that the optimum matrix with (7.5 %) wt. % has the lowest value about (0.443 k.w\m .c).

        The results show that the blend reinforced with nano clay in a weight fraction (7.5)% has the best sound insulation, so that the sound intensity started at (99.8) db at 100 Hz., and reached (101.3) db at 10000 Hz., which is much lower than the values obtained from the unreinforced blend, of which the sound intensity started at (107.2) db and reached (108.7) db., applying the same range of frequencies. The same casting (blend+7.5% nanoclay) showed the lowest value of thermal conductivity (xxxx) W.m°C in comparison with castings that were made of unreinforced blend and those  hybridized with rockwool.

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Publication Date
Fri Jul 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
Performance Evaluation for Higher and Medium Leadership in Institutional Work Quality.
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This Research aims to define role of the system of evaluating the performance for higher leadership in determining the level of institutional work quality in the Ministry of Agriculture, by measuring system efficiency of evaluating the performance for higher leadership and its effect in institutional work quality, the searcher reached through the theoretical framing and involved studies to build default plan define the relation between Research variables formed from system of evaluating leadership performance as independent variable contains six subsidiary dimensions: (Polarization, evaluating the performance of personnel, training, motivation, se

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Publication Date
Sat Dec 01 2018
Journal Name
Political Sciences Journal
Iraq after war and strategy of reconstruction : Analytical study in reality and future horizon
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Abstract (Iraq post – war reconstruction strategy: analytical study in fact and future prospects.) There search aims at identifying the causes of internal instability in Iraq from the political ,economic , social and security aspects , to diagnose the imbalance and to work towards finding real solutions to this . The study also aims at identifying the reconstruction proposals to completely eliminate the organizationof the terrorist advocate, as well as to know. theproblem of research lies in the ability of Iraqi political elites to achieve internal stability and to employ reconstruction proposals at all levels . The hypothesis of the research lies in the equation that the process of building stability (political – economic)and (socia

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Publication Date
Mon Jan 07 2013
Journal Name
Nanoscience And Nanotechnology
Low Frequency Dielectric Study of PAPA-PVA-GR Nanocomposites
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Publication Date
Tue Jan 01 2019
Journal Name
Aip Conference Proceedings
Electrical characteristics of nickel/epoxy - Unsaturated polyester blend nanocomposites
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Publication Date
Tue Feb 28 2017
Journal Name
Journal Of Engineering
Non-Isothermal Crystallization Kinetics Model of PBT/ MWCNTs Nanocomposites
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The non-isothermal crystallization kinetics and crystalline properties of nanocomposites poly butyleneterephthalate, [PBT] /multiwalled-carbon nanotubes (MWCNTs) were tested by differential scanning calorimetry (DSC). PBT/(MWCNTs) nanocomposite was prepared by ultrasonicated of MWCNTs (0.5, 1, 2, 4 wt %) in dichloromethane (DCM) and after that the powdered PBT polymer was added to the MWCNTs solution. The non-isothermal crystallization results show that increasing the MWCNTs contents, decreased the melting temperature (Tm) of PBT/(MWCNTs) nanocomposite as compared with pure PBT, while resulting in improving the degree of crystallinity. These results indicated that a little amount of MWCNTs can be evident strong nucleating agent in PBT na

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Publication Date
Fri Jul 21 2023
Journal Name
Journal Of Engineering
Simulation of Heat Storage and Heat Regeneration in Phase Change Material
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The present study explores numerically the energy storage and energy regeneration during Melting and Solidification processes in Phase Change Materials (PCM) used in Latent Heat Thermal Energy Storage (LHTES) systems. Transient two-dimensional (2-D) conduction heat transfer equations with phase change have been solved utilizing the Explicit Finite Difference Method (FDM) and Grid Generation technique. A Fortran computer program was built to solve the problem. The study included four different Paraffin's. The effects of container geometrical shape, which included cylindrical and square sections of the same volume and heat transfer area, the container volume or mass of PCM, variation of mass flow rate of heat transfer fluid (HTF), and temp

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Publication Date
Mon Dec 18 2017
Journal Name
Al-khwarizmi Engineering Journal
Fabrication of Carbon Nanotube Reinforced Al2O3/Cr2O3 Nanocomposites by Coprecipitation Process
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In this research, the effect of multi-walled carbon nanotubes (MWCNTs) on the alumina/chromia (Al2O3/Cr2O3) nanocomposites has been investigated. Al2O3/Cr2O3-MWCNTs nanocomposites with variable contents of Cr2O3 and MWCNTs were fabricated using coprecipitation process and followed by spark plasma sintering. XRD analysis revealed a good crystallinity of sintered nanocomposites samples and there was only one phase presence of Al2O3-Cr2O3 solid solution. Density, Vickers microhardness, fracture toughness and fracture strength have been measured in the sintered samples. The results show tha

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Publication Date
Tue Jan 01 2019
Journal Name
Energy Procedia
Humidity effect on diffusion and length coefficient of radon in soil and building materials
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Publication Date
Fri Feb 01 2019
Journal Name
Journal Of The College Of Education For Women
The Sound of the letter (ق) in the Contemporary Arabic Dialects
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The Sound of the letter (ق) in the Contemporary Arabic Dialects

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Publication Date
Mon Mar 25 2019
Journal Name
Al-academy
The Aesthetics of Sound Use in Cinematography Discourse: مهيمن اسماعيل افرام
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The sound in the cinema and television occupies a large space in the level of use and expression. In addition to the functional aspect of the elements of the sound such as the dialogue, music, effects and silence, in shaping and supporting the narrative structure of the image in the dramatic work, it has today become and in light of the technical developments of the sound, an aesthetic value in the structure and formulation of the contents and ideas presented in the work. The sound also created a variety of forms before the work-factories in the artistic functioning, which enhances the emotional and expressive dimension of the image, and the researcher, as a result of many new developments in the expression o

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