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bsj-4136
Thermal Conductivity Performance of Silica Aerogel after Exposition on Different Heating under Ambient Pressure
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         The varied thermal conductivity (insulation) of silica aerogel with heating for different pH has been investigated, it has been depended on ambient pressure drying method in the preparing silica aerogel samples, also six different pH of samples (1, 2, 3, 7, 8 and 9) were treated under five degree of heating with (50,100,150,200 and 250) ᴼC. This technique is important to test the carry-outs hydrophobic silica to temperature without high-quality material changes in the basic characteristics. The hot-wire technique is used in this work to examine the thermal conductivity, Fourier Transform Infrared Spectroscopy (FTIR) depended to characterize the bonds and their artificial by heating. Results show that the samples affected by heating through decreasing the density leading to obtaining more insulation metal, moreover varied pH is an important role in thermal conductivity. The average thermal conductivity of all aerogel samples in this work is (0.01- 0.0061 mW m-10 C-1) this means that it is still below thermal conductivity for air equals to (0.02257) mW m-10 C-1 . Meanwhile, we concluded that the insulation property of silica aerogel is affected by heat treatment and gives it more thermal insulation property.

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Publication Date
Fri Dec 31 2021
Journal Name
Iraqi Journal Of Laser
Laser Microdrilling and Nanodrilling of 8009 Aluminium Alloy using Nanoparticles
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 The microdrilling and nanodrilling holes are produced by a Q-switched Nd :YAG laser (1064 nm) interaction with 8009 Al alloy using nanoparticles. Two kinds of nanoparticles were used with this alloy. These nanoparticles are tungsten carbide (WC) and silica carbide (SiC). In this work, the microholes and nanoholes have been investigated with different laser pulse energies (600, 700 and 800)mJ, different repetition rates (5Hz and 10Hz) and different concentration of nanoparticles (90%, 50% and 5% ). The results indicate that  the microholes and nanoholes have been achieved when the laser pulse energy is 600 mJ, laser repetition rate is 5Hz, and the concentration of the  nanoparticles (for the two types of n

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Publication Date
Sat Feb 01 2020
Journal Name
Alexandria Engineering Journal
Impact of development on Baghdad’s urban microclimate and human thermal comfort
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Publication Date
Thu Jun 30 2011
Journal Name
Al-khwarizmi Engineering Journal
Performance Improvement of Neural Network Based RLS Channel Estimators in MIMO-OFDM Systems
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The objective of this study was tointroduce a recursive least squares (RLS) parameter estimatorenhanced by using a neural network (NN) to facilitate the computing of a bit error rate (BER) (error reduction) during channels estimation of a multiple input-multiple output orthogonal frequency division multiplexing (MIMO-OFDM) system over a Rayleigh multipath fading channel.Recursive least square is an efficient approach to neural network training:first, the neural network estimator learns to adapt to the channel variations then it estimates the channel frequency response. Simulation results show that the proposed method has better performance compared to the conventional methods least square (LS) and the original RLS and it is more robust a

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Publication Date
Sun May 01 2016
Journal Name
Journal Of Engineering
Temperature Effect on Power Drop of Different Photovoltaic Modules
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Solar module operating temperature is the second major factor affects the performance of solar photovoltaic panels after the amount of solar radiation. This paper presents a performance comparison of mono-crystalline Silicon (mc-Si), poly-crystalline Silicon (pc-Si), amorphous Silicon (a-Si) and Cupper Indium Gallium di-selenide (CIGS) photovoltaic technologies under Climate Conditions of Baghdad city. Temperature influence on the solar modules electric output parameters was investigated experimentally and their temperature coefficients was calculated. These temperature coefficients are important for all systems design and sizing. The experimental results revealed that the pc-Si module showed a decrease in open circuit v

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Publication Date
Sun Oct 01 2017
Journal Name
Journal Of Economics And Administrative Sciences
Evaluating the performance of Inspector General Office of the Ministry of health in accordance with normative people and people results for the European excellence model EFQM 2013
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Abstract:

Current research has sought to apply the criteria of potential for altmizalaorbi model EFQM 2013 in assessing the performance of the Inspector General's Office/Ministry of health, so as to keep up with a modern and advanced management methods in the evaluation of performance, as well as to link performance to a citizen's life, and it takes him beyond the accepted service capabilities today, but of budget duties between dealers servicing responsibilities and future planning, financial control, competitiveness, human resources needs and maintaining quality and development, as well as the constant quest for continuous improvement, is the spirit of the principle underpinning the European Foundation Quality managemen

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Publication Date
Wed Oct 01 2025
Journal Name
Al-anbar University Journal Of Law And Political Sciences
شرط التفاوض تحت رقابة الغير "دراسة مقارنة"
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Publication Date
Mon Mar 01 2004
Journal Name
Al-academy
تصنيع الطابوق الحراري الثقيل من خامات محلية
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تصنيع الطابوق الحراري الثقيل من خامات محلية

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Publication Date
Thu Jun 01 2017
Journal Name
Journal Of Economics And Administrative Sciences
Use some of the scheduling rules for nursing staffs to improve operational performance _ Applied Research in al- Shahed al-Sadr General Hospital
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             Hospitals are part of the service organizations and most importantly at the level of individuals because they are tied to the people health and their daily lives , the nursing service is one of the important services provided by hospitals, and nurses are the human resource that offers this service, from this standpoint the idea of  ​​research came to prepare work Scheduling for nurses in a scientific way to improve performance operational for their services and provide efficient service available 24 hours a day, the research use one of the modern and scientific rules of scheduling its “schedule of

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Publication Date
Thu Jun 04 2020
Journal Name
Fibers
A Comparative Study of the Performance of Slender Reinforced Concrete Columns with Different Cross-Sectional Shapes
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Most reinforced concrete (RC) structures are constructed with square/rectangular columns. The cross-section size of these types of columns is much larger than the thickness of their partitions. Therefore, parts of these columns are protruded out of the partitions. The emergence of columns edges out of the walls has some disadvantages. This limitation is difficult to be overcome with square or rectangular columns. To solve this problem, new types of RC columns called specially shaped reinforced concrete (SSRC) columns have been used as hidden columns. Besides, the use of SSRC columns provides many structural and architectural advantages as compared with rectangular columns. Therefore, this study was conducted to explain the structura

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Publication Date
Thu Mar 25 2021
Journal Name
Dental Materials Journal
Mechanical and thermal stress evaluation of PEEK prefabricated post with different head design in endodontically treated tooth: 3D-finite element analysis
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