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ijp-1084
Bandwidth Improvement of a Cone-Inverted Cylindrical and Cross Hybrids Dielectric Resonator Antennas
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In this work, two cone-inverted cylindrical and cross-hybrid dielectric resonator antennas are stacked and excited by the coaxial probe method with an operating standard resonant frequency of 5.438 GHz. A drawback of these standard Dielectric Resonator Antennas (DRAs) is their narrow bandwidth. For good antenna performance, a stacked DR geometry and a thick dielectric substrate having a low dielectric constant are desired since this provides large bandwidth, better radiation power, reduces conductor loss and nonappearance of surface waves. Many approaches, such as changing the shape of the dielectric resonator, have been used to enhance bandwidth. Using DRA, having the lowest dielectric constant, increases the bandwidth and the electromagnetic energy. In the current work, bandwidth improvement was significantly achieved by the proposed geometry by varying the antenna size.  A novel hybrid DRA configuration is used to increase the bandwidth of the antenna to 89.27% and 149.23% due to cone-inverted cylindrical and cross-hybrid dielectric resonator antennas, respectively. The DRA is designed numerically via Finite Difference Time Domain (FDTD) method. Several parameters like return loss, input impedance (verified at ) and radiation pattern are calculated. Furthermore, the stacked-hybrid technique is used to enhance the antenna's performance which is useful for broadband communication and the demand of wireless.

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Publication Date
Thu Mar 01 2018
Journal Name
Journal Of Engineering
Improvement of the Water Use Efficiency and Yield of Eggplant by Using Subsurface Water Retention Technology
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Sustainable crop production in a coarse soil texture is challenging due to high water permeability and low soil water holding capacity. In this paper, subsurface water retention technology (SWRT) through impermeable polyethylene membranes was placed at depth 35 cm below ground surface and within the root zone to evaluate and compare the impact of these membranes and control treatment (without using the membranes) on yield and water use efficiency of eggplant inside the greenhouse. The study was conducted in Al-Fahamah Township, Baghdad, Iraq during spring growing season 2017. Results demonstrated the yield and water use efficiencies were 3.483 kg/m2 and 5.653 kg/m3, respectively for SWRT treatment p

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Publication Date
Sun Mar 06 2016
Journal Name
Baghdad Science Journal
Investigation of the dielectric Properties of (PPAB) terminated by phenylenediamine doped by Na2[Fe(CN)5.NO].2H2O using Lumped equivalent circuit
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The aim of this paper is to demonstrate the effect of Na2[Fe(CN)5.NO].2H2O impurity (0.1 M) concentration on the dielectrical properties of poly (P-Aminobenzaldehyde) terminated by pheneylenediamine in the frequency and temperature ranges (1-100)KHz and (283-348) K respectively.These properties include dissipation factor, series and parallel resistance, series and parallel capacitance, real and imaginary part of the dielectric constant, a.c conductivity and impedance (real and imaginary) part, that have been deduced from equivalent circuit. The investigation shows that adding Na2[Fe(CN)5.NO].2H2O as additive to the polymer lead to increase of the dielectric constant with increasing temperature and it is decreasing with increasing the freq

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Publication Date
Mon Jan 01 2024
Journal Name
Journal Of Engineering
Improvement Marshall Properties of Hot Mix Asphalt Concrete Using Polyphosphoric Acid
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Modified asphalt is considered one of the alternatives to address the problems of deficiencies in traditional asphalt concrete, as modified asphalt addresses many of the issues that appear on the pavement layers in asphalt concrete, resulting from heavy traffic and vehicles loaded with loads that exceed the design loads and the large fluctuations in the daily and seasonal temperatures of asphalt concrete. The current study examined the role of polyphosphoric acid (PPA) as a modified material for virgin asphalt when it was added in different proportions (1%, 2%, 3%, 4%) of the asphalt weight. The experimental program includes the volumetric characteristics associated with the Marshall test, the physical properties, and th

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Publication Date
Mon Jun 19 2023
Journal Name
Journal Of Engineering
Improvement of Soil by Using Polymer Fiber Materials Underneath Square Footing
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The change in project cost, or cost growth, occurs from many factors, some of which are related to soil problem conditions that may occurs during construction and/or during site investigation period. This paper described a new soil improvement method with a minimum cost solution by using polymer fiber materials having a length of (3 cm) in both directions and (2.5 mm) in thickness, distributed in uniform medium dense .
sandy soil at different depths (B, 1.5B and 2B) below the footings. Three square footings has been used (5,7.5 and 10 cm) to carry the above investigation by using lever arm loading system design for such purposes.
These fibers were distributed from depth of (0.1B) below the footing base down to the investigated dep

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Publication Date
Sun Mar 07 2010
Journal Name
Baghdad Science Journal
Improvement of thermostable productivity ?-amylase from local isolate Bacillus licheniformis H14.
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(28)Bacterial local isolates of Bacillus sp. were obtained from soil samples. Isolates were tested for thermostable alpha- amylase production on solid media; fifteen isolates were able to develop clear zone around the bacterial growth after floating the plates with iodine reagent (Lugol's solution). There were further tested in submerged culture which led to selection of Bacillus sp. H14since it was the most efficient .Microbial and biochemical tests showed that the local isolate Bacillus sp.H14was refered to the species B.licheniformis that signed as H14 was refered to the species B.licheniformis H14 .,To get ahigher yield of alpha – amylase(48.70unit/mg protein) production from the local isolate B.licheniformis H14 . This study used

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Publication Date
Thu Jun 10 2010
Journal Name
Iraqi Journal Of Laser
Improvement of Nonlinear Optical Properties for Mixture Laser Dyes Doped PMMA
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The spectral characteristics and the nonlinear optical properties of the mixed donor (C-480) acceptor (Rh-6G) have been determined. The spectral characteristics are studied by recording their absorption and fluorescence spectra. The nonlinear optical properties were measured by z-scan technique, using Q-switched Nd: YAG laser with 1064 nm wavelength. The results showed that the optimum concentration of acceptor is responsible for increasing the absorption and the emission bandwidth of donor to full range and to 242 nm respectively by the energy transfer process, also the efficiency of the process was increased by increasing the donor and acceptor concentration. The obtained nonlinear properties results of the mixture C-480/ Rh-6G showed

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Publication Date
Sat Jan 01 2011
Journal Name
Iraqi Journal Of Physics
Radiation contrast improvement by suitable choice of x-ray radiation spectrum
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Different bremsstrahlung spectra from tungsten anode x-ray tube generated at 30, 40 and 50 kV have been examined theoretically and experimentally for an attempt to find a most suitable spectrum to radiograph a test object of 0.01 cm thickness of Cu and Ag. The high contrast using this suitable spectrum is demonstrated and the possible effects of fluorescent radiation are discussed.

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Publication Date
Mon Mar 13 2017
Journal Name
Journal Of Baghdad College Of Dentistry
Buccal Cortical Bone Thickness in Iraqi Arab Adults by Cone Beam Computed Tomography for Orthodontic Mini-Implants
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ABSTRACT Background: Cortical bone thickness is important for the stability of mini implants. Placing mini implants in sites of favorable cortical bone thickness would guarantee better initial stability and long-term success. The aim of this study was to investigate gender, side and jaw differences of the buccal cortical bone thickness as a guide for orthodontic mini screw placement. Materials and Methods: The sample was selected from the patients attending the Specialized Health Center in Al-Sadr City / 3D department. Thirty patients (15 males and 15 females) were selected and cone beam computerized tomographic images were done. Then the buccal cortical bone thickness was measured at thirteen inter radicular sites in the maxilla and mandib

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Publication Date
Thu Mar 15 2018
Journal Name
Journal Of Baghdad College Of Dentistry
Radiological Evaluation of the Anatomic Characteristic of Lingual Foramina and Their Vascular Canals in the Anterior Region of the Mandible Using Cone Beam Computed Tomography
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Background: presence of lingual vascular foramina and canals in the interforaminal region may increase the risk ofsurgical complications during implant placement or any surgical procedure in this area. Aim of this study is the radiological evaluation of the anatomic characteristic of the lingual foramina and their vascular canals in the anterior of the mandible using cone beam computed tomography. Materials and Methods: Prospective study including 72 Iraqi subjects (31 male and 41 female) ranging from 20 to 59 years, all subjects attended Al-Sharaa dental clinic in AL-Najaf AL-Ashraf city, scanned with CBCT from September 2016 to February 2017. Using 3dimentional and sagittal cross section to detect lingual foramina and their vascular canal

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Publication Date
Fri Dec 15 2017
Journal Name
Journal Of Baghdad College Of Dentistry
Radiological Evaluation of The Anatomic Characteristic of Lingual Foramina and Their Vascular Canals in The Anterior Region of The Mandible Using Cone Beam Computed Tomography
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Background: presence of lingual vascular foramina and canals in the interforaminal regionmay increase the risk ofsurgical complications during implant placement or any surgical procedure in this area.Aim of this study is the radiological evaluation of the anatomic characteristic of the lingual foramina and their vascular canals in the anterior of the mandible using cone beam computed tomography. Materials and Methods: Prospective study including 72 Iraqi subjects (31 male and 41 female) ranging from 20 to 59 years, all subjects attended AL- Sharaa dental clinic in AL-Najaf AL-Ashraf city, scanned with CBCT from September 2016 to February 2017. Using 3dimentional and sagittal cross section to detect lingual foramina and their vascular canals

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