Design and numerical verification of a polarization-independent grating coupler using a double-layer approach for visible wavelengths applications
(1)
Publication Date
Sun May 17 2020
Journal Name
Iraqi Journal Of Science
Deriving The Upper Blow-up Rate Estimate for a Parabolic Problem
Blow-up solutions
Parabolic problem
Heat equation
Neumann boundary condition
outward normal vector
In this paper, the blow-up solutions for a parabolic problem, defined in a bounded domain, are studied. Namely, we consider the upper blow-up rate estimate for heat equation with a nonlinear Neumann boundary condition defined on a ball in Rn.
(1)
Publication Date
Sun Dec 01 2019
Journal Name
Applied Soft Computing
(7)
(5)
Publication Date
Mon Jan 01 2024
Journal Name
Lecture Notes In Networks And Systems
Publication Date
Tue Sep 01 2015
Journal Name
Nano Science And Nano Technology
Preparation CuInSe2 (CIS) by arrested precipitation method as alight absorption layer of photovoltaic solar-cells
CuInSe2
Nanoink
Arrested precipitation
Selenization
Ar- Atmosphere
The CuInSe2 (CIS) nanocrystals are synthesized by arrested precipitation from molecular precursors are added to a hot solvent with organic cap- ping ligands to control nanocrystal formation and growth. CIS thin films deposited onto glass substrate by spray - coating, then selenized in Ar- atmosphere to form CIS thin films. PVs were made with power conversion efficiencies of 0.631% as -deposited and 0.846% after selenization, for Mo coated, under AM 1.5 illumination. X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS) analysis it is evident that CIS have the chalcopyrite structure as the major phase with a preferred orientation along (112) direction and the atomic ratio of Cu : In : Se in the nanocrystals is nearly 1 : 1 : 2
Publication Date
Fri May 01 2015
Journal Name
Journal Of Engineering
A Real-Coded Genetic Algorithm with System Reduction and Restoration for Rapid and Reliable Power Flow Solution of Power Systems
load flow analysis
load modeling
power system modeling
real coded genetic algorithms
simulation
voltage measurement
The paper presents a highly accurate power flow solution, reducing the possibility of ending at local minima, by using Real-Coded Genetic Algorithm (RCGA) with system reduction and restoration. The proposed method (RCGA) is modified to reduce the total computing time by reducing the system in size to that of the generator buses, which, for any realistic system, will be smaller in number, and the load buses are eliminated. Then solving the power flow problem for the generator buses only by real-coded GA to calculate the voltage phase angles, whereas the voltage magnitudes are specified resulted in reduced computation time for the solution. Then the system is restored by calculating the voltages of the load buses in terms
... Show MorePublication Date
Fri Jul 29 2022
Journal Name
Journal For Vascular Ultrasound
A Comparative Study of the Right and Left Carotid Arteries in Relation to Age for Patients With Diabetes and Hypertension
Introduction:
Introduction: Age
hypertension
and diabetes can cause significant alterations in arterial structure and function
including
changes in lumen diameter (LD)
intimal-medial thickness (IMT)
flow velocities
and arterial compliance. These are also considered
risk markers of atherosclerosis and cerebrovascular disease. A difference between right and left carotid artery blood flow and
IMT has been reported by some researchers
and a difference in the incidence of nonlacunar stroke has been reported between
the right and left brain hemispheres. The aim of this study was to determine whether there are differences between the right and
left common carotid arteries and internal carotid arteries in patients with hypertension and diabetes for 2 age groups.
Methods: We studied 250 patients with both diabetes and hypertension. Patients were divided into 2 age groups with the
old age group being 56 to 75 years and the young age group 35 to 55 years. The bilateral common carotid and internal carotid
arteries were evaluated with B-mode ultrasound and Doppler examinations. The LD and IMT were measured for both common
carotid arteries
and spectral waveform parameters and indices were recorded for both internal carotid arteries.
Results: The difference in LD between the left and right common carotid arteries for the old age group was 11.64% and for the
young age group was 6.42%
with significant P values of <.05 for both age groups. The difference in IMT between the left and
right common carotid arteries was 18.27% in the old age group compared with 15.38% in the young age group
with significant
P values of <.05. There was a difference in peak systolic velocity between the left and right internal carotid arteries of 4.85%
in the old age group which was not significant
compared with 14.28% in the young age group with a significant P value <.05
whereas the difference in end-diastolic velocity between the left and right internal carotid arteries was not significant for both
age groups. Differences between the right and left internal carotid arteries for resistive index
pulsatility index
and pressure
gradient were significant only in the young age group.
Conclusion: We found significant differences between the right and left common carotid and internal carotid arteries in
patients with diabetes and hypertension which were more prominent in the young age group. Values for common carotid IMT
and LD were significantly higher in the left common carotid artery versus the right common carotid artery in both age groups.
Differences between the 2 carotid sides may be attributed to anatomic variations in the common carotid artery origins which
lead to differences in stress between the 2 sides
Age, hypertension, and diabetes can cause significant alterations in arterial structure and function, including changes in lumen diameter (LD), intimal-medial thickness (IMT), flow velocities, and arterial compliance. These are also considered risk markers of atherosclerosis and cerebrovascular disease. A difference between right and left carotid artery blood flow and IMT has been reported by some researchers, and a difference in the incidence of nonlacunar stroke has been reported between the right and left brain hemispheres. The aim of this study was to determine whether there are differences between the right and left common carotid arteries and internal carotid arteries in patient
(5)
(2)
Publication Date
Mon Mar 18 2019
Journal Name
Al-khwarizmi Engineering Journal
Best Level of Parameters for a Critical Buckling Load for Circular Thin- Walled Structure Subjected to Bending
Circular thin walled structures have wide range of applications. This type of structure is generally exposed to different types of loads, but one of the most important types is a buckling. In this work, the phenomena of buckling was studied by using finite element analysis. The circular thin walled structure in this study is constructed from; cylindrical thin shell strengthen by longitudinal stringers, subjected to pure bending in one plane. In addition, Taguchi method was used to identify the optimum combination set of parameters for enhancement of the critical buckling load value, as well as to investigate the most effective parameter. The parameters that have been analyzed were; cylinder shell thickness, shape of stiffeners section an
... Show More
Publication Date
Tue Sep 08 2020
Journal Name
Baghdad Science Journal
Convergence Analysis for the Homotopy Perturbation Method for a Linear System of Mixed Volterra-Fredholm Integral Equations
Homotopy perturbation method
linear system of second kind mixed Volterra-Fredholm integral equations.
In this paper, the homotopy perturbation method (HPM) is presented for treating a linear system of second-kind mixed Volterra-Fredholm integral equations. The method is based on constructing the series whose summation is the solution of the considered system. Convergence of constructed series is discussed and its proof is given; also, the error estimation is obtained. Algorithm is suggested and applied on several examples and the results are computed by using MATLAB (R2015a). To show the accuracy of the results and the effectiveness of the method, the approximate solutions of some examples are compared with the exact solution by computing the absolute errors.
(5)
(1)
Publication Date
Fri Nov 01 2019
Journal Name
Indian Journal Of Natural Sciences
The Numerical and Experimental Work of Chaos System in Three Dimensions Phase Spaceusing Rossler Circuit
In this paper, we deal with a dynamical system that can demonstrate a chaotic attractor of Rossleroscillator. We simulate the Rosslerequations numerically then we investigate the model experimentally. Numerically, the Rossler parameter a and b were fixed and c was changed.The evolution of the system exhibits period, period-doubling, second period doubling, and chaos when control parameters are changed. This evolution can be seen by analyze the time series, the bifurcation diagrams and phase space. Experimentally, the evolution of the system exhibited the same numerical behavior by changing the resistance (Rv) in Rossler circuit that represent as control parameter.
Publication Date
Sat Feb 06 2021
Journal Name
Engineering, Technology & Applied Science Research
Experimental and Numerical Analysis of Bubbles Distribution Influence in BubbleDeck Slab under Harmonic Load Effect
Reducing a structure’s self-weight is the main goal and a major challenge for most civil constructions, especially in tall buildings and earthquake-affected buildings. One of the most adopted techniques to reduce the self-weight of concrete structures is applying voids in certain positions through the structure, just like a voided slab or BubbleDeck slab. This research aims to study, experimentally and theoretically, the structural behavior of BubbleDeck reinforced concrete slabs under the effect of harmonic load. Tow-way BubbleDeck slab of 2500mm×2500m×200mm dimensions and uniformly distributed bubbles of 120mm diameter and 160mm spacing c/c was tested experimentally under the effect of harmonic load. Numerical analysis was als
... Show More