Preferred Language
Articles
/
eRY3n4oBVTCNdQwCWqHi
MODELING AND COMPARISON OF CLOSED-LOOP AND OPENLOOP ADAPTIVE OPTICS SYSTEMS
...Show More Authors

Astronomers have known since the invention of the telescope that atmospheric turbulence affects celestial images. So, in order to compensate for the atmospheric aberrations of the observed wavefront, an Adaptive Optics (AO) system has been introduced. The AO can be arranged into two systems: closedloop and open-loop systems. The aim of this paper is to model and compare the performance of both AO loop systems by using one of the most recent Adaptive Optics simulation tools, the Objected-Oriented Matlab Adaptive Optics (OOMAO). Then assess the performance of closed and open loop systems by their capabilities to compensate for wavefront aberrations and improve image quality, also their effect by the observed optical bands (near-infrared band and visible band), the shape of the telescope aperture (circular and hexagonal) and the atmospheric seeing conditions. The results showed that open-loop systems perform better than closed-loop systems at good seeing and vice versa. Also showed that closed-loop provides stability in the correction process over time, while the open-loop is a faster phase compensator

View Publication
Publication Date
Thu Apr 12 2018
Journal Name
Lubricants
Importance of Emulsification in Calibrating Infrared Spectroscopes for Analyzing Water Contamination in Used or In-Service Engine Oil
...Show More Authors

View Publication
Scopus (14)
Crossref (11)
Scopus Crossref
Publication Date
Sun Feb 02 2025
Journal Name
Engineering, Technology & Applied Science Research
A Numerical Study of Concrete Composite Circular Columns encased with GFRP I-Section using the Finite Element Method
...Show More Authors

This paper presents ABAQUS simulations of fully encased composite columns, aiming to examine the behavior of a composite column system under different load conditions, namely concentric, eccentric with 25 mm eccentricity, and flexural loading. The numerical results are validated with the experimental results obtained for columns subjected to static loads. A new loading condition with a 50 mm eccentricity is simulated to obtain additional data points for constructing the interaction diagram of load-moment curves, in an attempt to investigate the load-moment behavior for a reference column with a steel I-section and a column with a GFRP I-section. The result comparison shows that the experimental data align closely with the simulation

... Show More
View Publication
Scopus (1)
Scopus Crossref
Publication Date
Sun Nov 07 2021
Journal Name
Review Of International Geographical Education Online
Requirements of Formulating a National Strategy for Developing the Cybersecurity System in Iraq According to GCI.v4(2019) Index
...Show More Authors

The present study aims to present a proposed realistic and comprehensive cyber strategy for the Communications Directorate for the next five years (2022-2026) based on the extent of application and documentation of cybersecurity measures in the Directorate and the scientific bases formulating the strategy. The present study is significant in that it provides an accurate diagnosis of the capabilities of the cyber directorate in terms of strengths and weaknesses in its internal environment and the opportunities and threats that surround it in the external environment, based on the results of the assessment of the reality of cybersecurity according to the global Cybersecurity index, which provides a strong basis for building its strategic dire

... Show More
Preview PDF
Scopus (3)
Scopus
Publication Date
Tue Nov 09 2021
Journal Name
Energies
Natural Convection Effect on Solidification Enhancement in a Multi-Tube Latent Heat Storage System: Effect of Tubes’ Arrangement
...Show More Authors

The solidification process in a multi-tube latent heat energy system is affected by the natural convection and the arrangement of heat exchanger tubes, which changes the buoyancy effect as well. In the current work, the effect of the arrangement of the tubes in a multi-tube heat exchanger was examined during the solidification process with the focus on the natural convection effects inside the phase change material (PCM). The behavior of the system was numerically analyzed using liquid fraction and energy released, as well as temperature, velocity and streamline profiles for different studied cases. The arrangement of the tubes, considering seven pipes in the symmetrical condition, are assumed at different positions in the system, i

... Show More
View Publication
Scopus (18)
Crossref (18)
Scopus Clarivate Crossref
Publication Date
Sun Feb 25 2024
Journal Name
Baghdad Science Journal
The Effect Of Optimizers On The Generalizability Additive Neural Attention For Customer Support Twitter Dataset In Chatbot Application
...Show More Authors

When optimizing the performance of neural network-based chatbots, determining the optimizer is one of the most important aspects. Optimizers primarily control the adjustment of model parameters such as weight and bias to minimize a loss function during training. Adaptive optimizers such as ADAM have become a standard choice and are widely used for their invariant parameter updates' magnitudes concerning gradient scale variations, but often pose generalization problems. Alternatively, Stochastic Gradient Descent (SGD) with Momentum and the extension of ADAM, the ADAMW, offers several advantages. This study aims to compare and examine the effects of these optimizers on the chatbot CST dataset. The effectiveness of each optimizer is evaluat

... Show More
View Publication Preview PDF
Scopus (3)
Crossref (1)
Scopus Crossref
Publication Date
Mon Jun 01 2020
Journal Name
Iop Conference Series: Materials Science And Engineering
The possibility of Using the Low-Cost External Antenna with Smartphone for Accurate Surveying Applications by RTX Technology
...Show More Authors
Abstract<p>Real Time Extended (RTX) technology works to take advantage of real-time data comes from the global network of tracking stations together with inventor locating and compression algorithms to calculate and relaying the orbit of satellite, satellite atomic clock, and any other systems corrections to the receivers, which lead to real-time correction with high accuracy. These corrections will be transferred to the receiver antenna by satellite (where coverage is available) and by IP (Internet Protocol) for the rest of world to provide the accurate location on the screen of smartphone or tablet by using specific software. The purpose of this study was to assess the accuracy of Global Navig</p> ... Show More
View Publication Preview PDF
Scopus (3)
Crossref (1)
Scopus Crossref
Publication Date
Fri Sep 01 2023
Journal Name
Journal Of Building Engineering
Discharge performance assessment of a vertical double-pipe latent heat storage unit equipped with circular Y-shaped fins
...Show More Authors

This paper aims to study the effect of circular Y-shaped fin arrangement to improve the low thermal response rates of a double-tube heat exchanger containing Paraffin phase change material (PCM). ANSYS software is employed to perform the computational fluid dynamic (CFD) simulations of the heat exchanger, including fluid flow, heat transfer, and the phase change process. The optimum state of the fin configuration is derived through sensitivity analysis by evaluating the geometrical parameters of the Y-shaped fin. For the same height of the fins (10 mm), the solidification time is reduced by almost 22%, and the discharging rate is enhanced by almost 26% using Y-shaped fins compared with the straight fins. The results demonstrate that the sol

... Show More
View Publication
Scopus (54)
Crossref (16)
Scopus Clarivate Crossref
Publication Date
Sun Dec 29 2019
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
The static aging effect on the seedless synthesis of different ranges FAU-type zeolite Y at various factors
...Show More Authors

This work investigates generating of pure phase Faujasite-type zeolite Y at the ranges chosen for this study via a static aging step in the absence of seeds synthesis. Nano-sized crystals may result when LUDOX AS-40 is used as a silica source for gel composition of range 6 and the crystallization step may be conducted for a period of 4 to 19 hr at 100 ⁰C. Moreover, large-crystals with high crystallinity pure phase Y zeolite can be obtained at hereinabove conditions but when hydrous sodium metasilicate is used as a silica source. The other selected ranges also offer pure phase Y zeolite at the same controlled conditions.

Crossref (14)
Crossref
Publication Date
Sun May 10 2020
Journal Name
Baghdad Science Journal
Temperature Impacts on the Cardiac Activity of the Snail Pomacea canaliculata from Shatt Al-Arab Region, Basrah, Iraq
...Show More Authors

The effects of temperature on an exotic aquatic snail Pomacea canaliculata  (Lamarck, 1819) collected from the Shatt Al-Arab intertidal zone were investigated. A series of laboratory experiments were conducted during the summer period of 2017. Individuals of new born snails hatched in the laboratory from adult snails were collected from Shatt Al-Arab intertidal zone, and subjected to five fixed temperatures: 15, 25, 35, 40 and 45 Cº, after short term thermal acclimation. The heartbeats (HB) were counted at each temperature level. The results showed significant  direct increase of HB from 15 Cº (19.8 HB/min) up to 25 Cº (76 HB/min) (P<0.05)  as well as from 25 Cº to 35 Cº (93 HB/min). At 40 Cº the snail HB

... Show More
View Publication Preview PDF
Scopus (2)
Crossref (1)
Scopus Clarivate Crossref
Publication Date
Thu Dec 01 2022
Journal Name
Chemical Data Collections
Removal of an anionic Eosin dye from aqueous solution using modified activated carbon prepared from date palm fronds
...Show More Authors

View Publication
Scopus (28)
Crossref (18)
Scopus Clarivate Crossref