Preferred Language
Articles
/
ijp-1084
Bandwidth Improvement of a Cone-Inverted Cylindrical and Cross Hybrids Dielectric Resonator Antennas
...Show More Authors

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.

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Fri Jun 20 2025
Journal Name
Baghdad Science Journal
The Role of Fear and Predator Dependent Refuge on a Stage Structure Prey-Predator System
...Show More Authors

The present paper investigates the role of fear and predator dependent refuge in the prey-predator system. The system describes the interaction between prey and a stage structure of predator that incorporates Holling II functional response. The predator splits into two compartments immature (juvenile) and mature (adult). The mature predators can hunt and reproduce but this capability is not found in the immature predators, the immature depend on their parents. The growth rate of prey decreases due to the existence of mature predators. The existence, uniqueness, and boundedness of the solution of the system are investigated. Three equilibrium points of the system are determined. The local stability of the system is studied. The global stabil

... Show More
View Publication
Scopus Clarivate Crossref
Publication Date
Sat Apr 01 2023
Journal Name
Journal Of Engineering
Estimation of Water and Energy Saving by Rainwater Harvesting: Sulaimani City as a Case Study
...Show More Authors

Rainwater harvesting could be a possible solution to decrease the consequences of water scarcity and energy deficiency in Iraq and the Kurdistan Region of Iraq (KRI). This study aims to calculate the water and energy (electricity) saved by rainwater harvesting for rooftops and green areas in Sulaimani city, KR, Iraq. Various data were acquired from different formal entities in Sulaimani city. Moreover, Google Earth and ArcMap 10.4 software were used for digitizing and calculating the total rooftop and green areas. The results showed that for the used runoff coefficients (0.8 and 0.95), the harvested rainwater volumes were 2901563 and 12197131 m³ during the study period (2005 – 2006) and (2019-2020). Moreover, by compa

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Wed Sep 01 2021
Journal Name
Acta Pharmaceutica Sinica B
Discovery of a potent and dual-selective bisubstrate inhibitor for protein arginine methyltransferase 4/5
...Show More Authors

View Publication
Scopus (22)
Crossref (22)
Scopus Clarivate Crossref
Publication Date
Wed Jun 01 2022
Journal Name
Journal Of Engineering
The Design and Simulation of a Novel Optical Adder Depending on Optical Tri-state Gates
...Show More Authors

Essential approaches involving photons are among the most common uses of parallel optical computation due to their recent invention, ease of production, and low cost. As a result, most researchers have concentrated their efforts on it. The Basic Arithmetic Unit BAU is built using a three-step approach that uses optical gates with three states to configure the circuitry for addition, subtraction, and multiplication. This is a new optical computing method based on the usage of a radix of (2): a binary number with a signed-digit (BSD) system that includes the numbers -1, 0, and 1. Light with horizontal polarization (LHP) (↔), light with no intensity (LNI) (⥀), and light with vertical polarization (LVP) (↨) is represen

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sat Jan 01 2022
Journal Name
International Journal Of Low-carbon Technologies
Performance evaluation of the photovoltaic thermal system with a fin array and surface zigzag layout
...Show More Authors
Abstract<p>Solar photovoltaic (PV) has many environmental benefits and it is considered to be a practical alternative to traditional energy generation. The electrical conversion efficiency of such systems is inherently limited due to the relatively high thermal resistance of the PV components. An approach for intensifying electrical and thermal production of air-type photovoltaic thermal (PVT) systems via applying a combination of fins and surface zigzags was proposed in this paper. This research study aims to apply three performance enhancers: case B, including internal fins; case C, back surface zigzags; and case D, combinations of fins and surface zigzags; whereas the baseline smooth duct rep</p> ... Show More
View Publication
Scopus (13)
Crossref (13)
Scopus Clarivate Crossref
Publication Date
Tue Jun 01 2021
Journal Name
Baghdad Science Journal
On Blow-up Solutions of A Parabolic System Coupled in Both Equations and Boundary Conditions
...Show More Authors

This paper is concerned with the blow-up solutions of a system of two reaction-diffusion equations coupled in both equations and boundary conditions. In order to understand how the reaction terms and the boundary terms affect the blow-up properties, the lower and upper blow-up rate estimates are derived. Moreover, the blow-up set under some restricted assumptions is studied.

View Publication Preview PDF
Scopus (11)
Crossref (3)
Scopus Clarivate Crossref
Publication Date
Thu Sep 15 2022
Journal Name
Journal Of Baghdad College Of Dentistry
Serum ferritin level and B12 in a sample of Iraqi re-current aphthous stomatitis patients
...Show More Authors

Background: Recurrent aphthous stomatitis (RAS) is one of the most common oral mucosal disorders with a prevalence of 50-66%. The prevalence of hematinic deficiencies including ferritin and vitamin B12 deficiencies and their role in the prophylaxis and development of RAS is not well known. Many studies have demonstrated a high prevalence of hematinic deficiencies in patients with RAS. This study aimed to compare the serum level of ferritin and vitamin B12 in patients with recurrent aphthous ulcers and healthy controls. Subjects, Materials and Methods: The data were collected from patients who needed blood analysis to exclude anemia from November 2020 to May 2021. The study was approved by the institutional ethics committee. After recordi

... Show More
View Publication Preview PDF
Scopus (3)
Crossref (3)
Scopus Crossref
Publication Date
Sun Jun 30 2019
Journal Name
Journal Of The College Of Education For Women
Common Origin of Languages: A Comparative Study between the Holy Quran and the Heavenly Religions
...Show More Authors

This research is a new reading of some of the words in the Holy Quran, which is very old. It is a human reading in which religions are intertwined by recognizing the relationship between man and his fellow man in the unity of existence and the unity of the source of religions and the unity of language. The importance of this research in comparing some of the Arabic words has been contained among books believed by followers that it is from the one God Sunday.

When words are spoken in one way in the form of one creature, from the beginning of creation to the present day, this indicates the single origin of the languages..

The research tools were books of heavenly religions, the Quran, dictionaries and interpretations.

... Show More
View Publication Preview PDF
Publication Date
Fri Nov 22 2019
Journal Name
Chalcogenide Letters
CONCENTRATION EFFECTS ON ELECTRONIC AND SPECTROSCOPIC PROPERTIES OF ZnCdS WURTZOIDS: A DENSITY FUNCTIONAL THEORY STUDY
...Show More Authors

Publication Date
Thu Dec 18 2025
Journal Name
Journal Of Baghdad College Of Dentistry
A Comparative Immunohistochemical Expression of Cyclin D1 in Keratocystic Odontogenic Tumor, Dentigerous and Radicular Cysts
...Show More Authors

Background: Odontogenic cysts include a group of osseodestructive lesions that frequently affect the jaws. Those cysts could derive from odontogenic epithelium and occur in the tooth-bearing regions of the jaws. The aims of this study were to evaluate the immunohistochemical expression of Cyclin D1 in Keratocystic Odontogenic Tumor, Dentigerous cyst and Radicular cyst in epithelium and connective tissue capsule. Materials and Methods: In this study, thirty formalin fixed paraffin embedded tissue blocks of Odontogenic cysts and Tumor, consist of 14 Keratocystic Odontogenic Tumor, 8 dentigerous cysts and 8 radicular cysts were analyzed immunohistochemically for the presence of Cyclin D1 proteins. Results: Strong to moderate expression of Cy

... Show More
View Publication Preview PDF
Crossref (1)
Crossref