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Enhancing the Performance of Piezoelectric Energy Harvesters Using Permanent Magnets
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A cantilevered piezoelectric beam with a tip mass at its free end is a common energy harvester configuration. This paper introduces a new principle of designing such a harvester which increases the generated voltage without changing the natural frequency of the harvester: The attraction force between two permanent magnets is used to add stiffness to the system. This magnetic stiffening counters the effect of the tip mass on the natural frequency. Three setups incorporating piezoelectric bimorph cantilevers of the same type in different mechanical configurations are compared theoretically and experimentally to investigate the feasibility of this principle. Theoretical and experimental results show that magnetically stiffened harvesters have important advantages over conventional setups. They generate more voltage and they can be tuned across a wide range of excitation frequencies.

 

 

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Publication Date
Sun May 02 2021
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Application of banking institutions' governance variables and their impact on financial performance as measured by (ROA & ROE): an applied study on a sample of local Islamic banks listed on the Iraq Stock Exchange
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The research seeks to achieve its goal of demonstrating the impact of applying banking governance variables on the financial performance of Islamic banks, and the independent research variables are represented by (X) by (the number of independent members in the board (X1), the number of directors in the board (X2), the number of committees emanating from the board ( X3), the percentage of shares owned by major shareholders in the board (X4), the number of members of the Sharia supervisory board (X5)), and the dependent variable (Y) is represented by (rate of return on assets (Y1), rate of return on equity (Y2)).

The research sample included (4) Islamic banks, namely (Iraqi Islamic Bank, National Islamic Bank, Jihan Islamic Bank,

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Publication Date
Tue Jun 20 2023
Journal Name
Baghdad Science Journal
Assessment of image quality of cervical spine complications using Three Magnetic Resonance Imaging Sequences
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Examining and comparing the image quality of degenerative cervical spine diseases through the application of three MRI sequences; the Two-Dimension T2 Weighed Turbo Spin Echo (2D T2W TSE), the Three-Dimension T2 Weighted Turbo Spin Echo (3D T2W TSE), and the T2 Turbo Field Echo (T2_TFE). Thirty-three patients who were diagnosed as having degenerative cervical spine diseases were involved in this study. Their age range was 40-60 years old. The images were produced via a 1.5 Tesla MRI device using (2D T2W TSE, 3D T2W TSE, and T2_TFE) sequences in the sagittal plane. The image quality was examined by objective and subjective assessments. The MRI image characteristics of the cervical spines (C4-C5, C5-C6, C6-C7) showed significant difference

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Publication Date
Sat Mar 01 2008
Journal Name
Iraqi Journal Of Physics
Smoothing of Image using adaptive Lowpass Spatial Filtering
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Lowpass spatial filters are adopted to match the noise statistics of the degradation seeking
good quality smoothed images. This study imply different size and shape of smoothing
windows. The study shows that using a window square frame shape gives good quality
smoothing and at the same time preserving a certain level of high frequency components in
comparsion with standard smoothing filters.

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Publication Date
Wed Apr 28 2021
Journal Name
Journal Of Engineering
Deasphalting of Atmospheric Iraqi Residue using Different Solvents
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Different solvents (light naphtha, n-heptane, and n-hexane) are used to treat Iraqi Atmospheric oil residue by the deasphalting process. Oil residue from Al-Dura refinery with specific gravity 0.9705, API 14.9, and 0.5 wt. % sulfur content was used. Deasphalting oil (DAO) was examined on a laboratory scale by using solvents with different operation conditions (temperature, concentration of solvent, solvent to oil ratio, and duration time). This study investigates the effects of these parameters on asphaltene yield. The results show that an increase in temperature for all solvents increases the extraction of asphaltene yield. The higher reduction in asphaltene content is obtained with hexane solvent at operating conditions of (90 °C, 4/1

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Publication Date
Mon Jan 01 2001
Journal Name
Scientific Nursing Journal
Labelling of circulating phagocyting cells using methylene blue
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To asses methylene blue as a cell marker, the cells of the buffy coat were labelled by incubating them in a medium containing a lable [Methylene blue] which is prepared in a concentration of 1%[1, 2, 3, 4, 5, 6] drops were tried at different periods of incubation [+/-,+/-, 1+/-, 1+/-] at 37 C degree. The results showed that monocytes and polymorphs are the main cells involved in the phagocytosis of this dye

Publication Date
Wed Apr 28 2021
Journal Name
Journal Of Engineering
Deasphalting of Atmospheric Iraqi Residue using Different Solvents
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Different solvents (light naphtha, n-heptane, and n-hexane) are used to treat Iraqi Atmospheric oil residue by the deasphalting process. Oil residue from Al-Dura refinery with specific gravity 0.9705, API 14.9, and 0.5 wt. % sulfur content was used. Deasphalting oil (DAO) was examined on a laboratory scale by using solvents with different operation conditions (temperature, concentration of solvent, solvent to oil ratio, and duration time). This study investigates the effects of these parameters on asphaltene yield. The results show that an increase in temperature for all solvents increases the extraction of asphaltene yield. The higher reduction in asphaltene content is obtained with hexane solvent at operating conditions of (90 °C

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Publication Date
Tue Aug 01 2023
Journal Name
Baghdad Science Journal
Degradation of Indigo Dye Using Quantum Mechanical Calculations
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The semiempirical (PM3) and DFT quantum mechanical methods were used to investigate the theoretical degradation of Indigo dye. The chemical reactivity of the Indigo dye was evaluated by comparing the potential energy stability of the mean bonds. Seven transition states were suggested and studied to estimate the actually starting step of the degradation reaction. The bond length and bond angle calculations indicate that the best active site in the Indigo dye molecule is at C10=C11.  The most possible transition states are examined for all suggested paths of Indigo dye degradation predicated on zero-point energy and imaginary frequency. The first starting step of the reaction mechanism is proposed. The change in enthalpy, Gibbs free energ

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Publication Date
Sat Jan 01 2022
Journal Name
Ieee Access
Assessment of Delamination Under Insulation Using Ridge Waveguide
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Publication Date
Thu May 22 2025
Journal Name
Journal Of Posthumanism
Impact of Using Dust / Fiber in Flexible Pavement
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Flexible paving is the most popular type of paving used in road building and one of the biggest problems facing the world's paving business is the rising demand for scarce natural resources. Uncontrolled. Numerous studies have shown that secondary materials reduce the need for traditional materials, offer efficient waste disposal technology and lower the overall cost of paving. The current study aimed to evaluate the efficiency of both fibers and dust on the sustainability and cost of flexible pavement by studying each of polyester fibers as a waste of the textile industry and fibers or rubber particles as one of the rubber waste products, in addition to studying the efficiency of using cement dust and marble dust on the paving proc

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Publication Date
Tue Sep 27 2022
Journal Name
Journal Of Engineering Research And Sciences
Images Compression using Combined Scheme of Transform Coding
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Some problems want to be solved in image compression to make the process workable and more efficient. Much work had been done in the field of lossy image compression based on wavelet and Discrete Cosine Transform (DCT). In this paper, an efficient image compression scheme is proposed, based on a common encoding transform scheme; It consists of the following steps: 1) bi-orthogonal (tab 9/7) wavelet transform to split the image data into sub-bands, 2) DCT to de-correlate the data, 3) the combined transform stage's output is subjected to scalar quantization before being mapped to positive, 4) and LZW encoding to produce the compressed data. The peak signal-to-noise (PSNR), compression ratio (CR), and compression gain (CG) measures were used t

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