Preferred Language
Articles
/
jih-3093
Simulation and Analysis the Attenuation Effect of Atmospheric Layers on a Laser Beam Within the Visible Range
...Show More Authors

Abstract: The power and the size of the final spot of the laser beam reaching the target are very important requirements in most of the laser applications and fields such as medical, military, and scientific, so studying laser propagation in the atmosphere is a very important topic. The propagation of the laser beam through the atmosphere is subject to several attenuation processes that deplete the power and expand the beam. Through the simulation results of the free electron laser within the visible region of the electromagnetic spectrum (400-700nm), it was found that the attenuation increases with decreasing wavelength. Laser propagation in the presence of rain and snow leads to a very large loss of power compared to propagation in normal weather conditions free of rain and snow. Atmosphere turbulence depends largely on changes in temperature, so the turbulence decreases with altitude from sea level, which makes laser work at high altitudes, such as the stratosphere, a good option with better results.

 

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Mon Aug 12 2024
Journal Name
Applied Physics A
Fabrication and characterization of visible-enhanced CeO2/Si photodetectors using pulsed laser deposition
...Show More Authors

Nanostructured photodetectors have garnered great attention due to their enriched electronic and optical properties. In this work, we aim to fabricate a high-performance CeO2/Si photodetector by growing a CeO2 nanostructure film on a silicon substrate using the pulsed laser deposition (PLD) technique at different laser energy densities. The impact of laser energy density and the number of pulses on the morphological, optical, and electrical properties was studied. Field emission scanning electron microscopy (FESEM) results show that the CeO2 film has a spherical grain morphology with an average grain size ranging from 33 to 54 nm, depending on the laser energy density. The film deposited at various numbers of laser pulses also has spherical

... Show More
View Publication
Scopus (1)
Scopus Clarivate Crossref
Publication Date
Thu Mar 01 2018
Journal Name
Journal Of Engineering
Numerical Simulation of Thermal-Hydrodynamic Behavior within Solar Air Collector
...Show More Authors

Solar collectors, in general, are utilized to convert the solar energy into heat energy, where it is employed to generate electricity. The non-concentrating solar collector with a circular shape was adopted in the present study. Ambient air is heated under a translucent roof where buoyant air is drawn from outside periphery towards the collector center (tower base). The present study is aimed to predict and visualize the thermal-hydrodynamic behavior for airflow under inclined roof of the solar air collector, SAC. Three-dimensional of the SAC model using the re-normalization group, RNG, k−ε turbulence viscus model is simulated. The simulation was carried out by using ANSYS-FLUENT 14.5. The simulation

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Oct 08 2002
Journal Name
Iraqi Journal Of Laser
Study of Laser Propagation Parameters in the Underdense Plasma Region Using a Two Dimensional Simulation Code
...Show More Authors

The propagation of laser beam in the underdense deuterium plasma has been studied via computer simulation using the fluid model. An appropriate computer code “HEATER” has been modified and is used for this purpose. The propagation is taken to be in a cylindrical symmetric medium. Different laser wavelengths (1 = 10.6 m, 2 = 1.06 m, and 3 = 0.53 m) with a Gaussian pulse type and 15 ns pulse widths have been considered. Absorption energy and laser flux have been calculated for different plasma and laser parameters. The absorbed laser energy showed maximum for  = 0.53 m. This high absorbitivity was inferred to the effect of the pondermotive force.

View Publication Preview PDF
Publication Date
Sat Mar 01 2025
Journal Name
Wasit Journal Of Engineering Sciences
Blue Laser Underwater Optical Visible Light Communication Using Recursive OFDM
...Show More Authors

Water covers more than 75% of the earth's surface in the form of the ocean. The ocean investigation is far-fetched because the underwater environment has distinct phenomenal activities. The expansion of human activities inside underwater environments includes environmental monitoring, offshore field exploration, tactical surveillance, scientific data collection, and port security. This led to increased demand for underwater application communication systems. Therefore, the researcher develops many methods for underwater VLC Visible Light Communications. The new technology of blue laser is a type of VLC that has benefits in the application of underwater communications. This research article investigated the benefits of underwater blu

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed May 10 2023
Journal Name
Journal Of Engineering
Effect of the Iranian Seperation Dikes on the Water Salinity Patterns Within Al Huweizah Marsh
...Show More Authors

Al Huweizah Marsh is considered as the largest marsh at the southern part of Iraq. About one third of the marsh is located within the Iranian territory. Iran began to construct earth dikes along the Iraqi-Iranian international borders to separate the Iranian part of the marsh. The electrical conductivity, EC, value was adopted to be the indicator for the water salinity within the marsh. A steady two-dimensional water quality routing model was implemented by using the RMA2 and RMA4 softwares within the SMS computer package to estimate the distribution of the
EC values within the marsh seasonally during the wet, moderate and dry water years. The EC distribution Patterns were estimated considering the expected two cases of the marsh futu

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Mar 13 2023
Journal Name
Diagnostics
The Effect of a Bioactive Oral System and CO2 Laser on Enamel Susceptibility to Acid Challenge
...Show More Authors

This study evaluated the structural changes of enamel treated by the Regenerate system and carbon dioxide (CO2) laser against acid challenge. Thirty human enamel slabs were prepared and assigned into three groups: Group I: untreated (control); Group II: treated with the Regenerate system; and Group III exposed to CO2 laser. All specimens were subjected to an acid challenge (pH 4.5–7.0) for 14 days. Specimens were evaluated and compared at 120 points using five Raman microspectroscopic peaks; the phosphate vibrations ν1, ν2, ν3, and ν4 at 960, 433, 1029, and 579 cm−1, respectively, and the carbonate at 1070 cm−1, followed by Vickers microhardness test. The ratio of carbonate to phosphate was correlated to the equivalent mic

... Show More
View Publication Preview PDF
Scopus (3)
Crossref (3)
Scopus Clarivate Crossref
Publication Date
Fri Feb 01 2019
Journal Name
Journal Of Economics And Administrative Sciences
The effect of Investment in Human Capital on Economic Growth in Algeria A standard Study within the period of: 1970 – 2015
...Show More Authors

The summary:

This research paper presents a standard economic study. This study aims to build an economic standard form of the investment effect in Human Capital on Economic Growth in Algeria. The study showed that there is an inverse relationship between the investment and human capital. This is expressed by expending on education and economic growth. This contradicts with the economic theory. Such matter could be explained by that expending on education does not contribute in the economic growth. This refers to that the education sector result does not employee or save jobs. Thus, it does not contribute in growth; in addition, the Algerian economy depends on petrol in the first class. This means the ab

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed May 10 2023
Journal Name
Journal Of Engineering
Vibration Control Analysis of a Smart Flexible Cantilever Beam Using Smart Material
...Show More Authors

This paper features the modeling and design of a pole placement and output Feedback control technique for the Active Vibration Control (AVC) of a smart flexible cantilever beam for a Single Input Single Output (SISO) case. Measurements and actuation actions done by using patches of piezoelectric layer, it is bonded to the master structure as sensor/actuator at a certain position of the cantilever beam.
The smart structure is modeled based on the concept of piezoelectric theory, Bernoulli -Euler beam theory, using Finite Element Method (FEM) and the state space techniques. The number of modes is reduced using the controllability and observability grammians retaining the first three
dominant vibratory modes, and for the reduced syste

... Show More
View Publication Preview PDF
Crossref (4)
Crossref
Publication Date
Mon Feb 04 2019
Journal Name
Journal Of The College Of Education For Women
The Analysis of Regional Development in Abu Ghraib Municipality within the Available Sources
...Show More Authors

The judgment enjoys many potential sources. If we look at these sources with analytical view that enable us to identify the potentials of strength in them which is the existence of features that distinct each place from the other one, which can be considered opportunities that provide the designer and the planner the possibility to design and planning which is based on subs taken from the reality of the available data of the location.
At this point outstands the role of development sources as one of the processes of re-configuring the place which appear as a result of a reality that requires setting new goals for the society and to achieve these goals it takes observations dealing with the place policies that should be taken, so this

... Show More
View Publication Preview PDF
Publication Date
Tue Dec 01 2009
Journal Name
Iraqi Journal Of Physics
Study of the heat treatment effect on electrical and porosity of Cermet Coating layers (Zro2 – Y2O3) prepared by Thermal Spraying
...Show More Authors

The technical of Flame Thermal Spray had been used in producing a cermet
composite based on powders of stabilized zirconium oxide containing amount of
Yatteria oxide (ZrO2- 8Y2O3) reiforced by minerals powders of bonding material
(Ni-Cr- Al- Y) in different rates of additions (25, 35, 50) on stainless steel base type
(304) after preparing it by the way of Grit Blasting.
Before heat treatment, the coated cermet layers were characterized for porosity
and electric resistivity. All samples were heat treated in vacuum furnace at different
temperature and times. The physical tests had been operated after heat treatment
and gave best results especially porosity, which found to be reduced dramatically
and producing hig

... Show More
View Publication Preview PDF