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Corneal Parameters Measurement in Healthy Subjects Using Scheimpflug and Anterior Segment Optical Coherence Tomography
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Purpose:  To compare the central corneal thickness (CCT),minimum corneal thickness (MCT) and corneal power measured using theScheimpflug-Placido device and optical coherence tomography (OCT) in healthy eyes. Study Design:  Descriptive observational. Place and Duration of Study:  Al-Kindy college of medicine/university of Baghdad, from June 2021 to April 2022. Methods:  A total of 200 eyes of 200 individuals were enrolled in this study. CCT and MCT measurements were carried out using spectral-domain optical coherence tomography (Optovue) and a Scheimpflug-Placido topographer (Sirius).The agreement between the two approaches was assessed using Bland-Altman analysis in this study. Results:  Mean age was 28.54 ± 6.6 years, mean spherical equivalent of refraction was -3.57 ± 3.35 D. Mean CCT by Optovue, and Sirius were534.13 ± 27.88 μm, and 540.2 ± 27.85μm, respectively.Mean CCT differences between them were -6.070± 6.593 μm, (p < 0.05). Minimum thickness by Optovue was 526.79 ± 27.81, and by Sirius was 537.44 ± 27.56, mean difference between the two devices was 10.66 ± 6.89,p= 0.00. The net power by OCT was 43.44 ± 1.456, mean K by Sirius was 43.597 ± 1.408, with p=0.000. Maximum level of agreement between the two devices is -18.99 to 6.85 for CCT, is widest for minimum thickness -24.166 to 2.85 and narrowest for differences between net corneal power by OCT and mean K By Sirius is -0.87 to 1.18. Conclusion:  In clinical practice, the two devices cannot be used interchangeably. CCT and keratometry should be evaluated and followed up using the same device.

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Publication Date
Tue Jun 12 2007
Journal Name
Iraqi Journal Of Laser
Nonlinear Optical Properties of CdS Thin Film Nanoparticles Using z-Scan Technique
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In the present work, a z-scan technique was used to study the nonlinear optical properties, represented by the nonlinear refractive index and nonlinear absorption coefficients of nanoparticles cadmium sulfide thin film. The sample was prepared by the chemical bath deposition method. Several testing were done including, x-ray, transmission and thickness of thin film. z-Scan experiment was performed at two wavelengths (1064 nm and 532 nm) and different energies. The results showed the effect of self-focusing in the material at higher intensities, which evaluated n2 to be (0.11-0.16) cm2/GW. The effect of two-photon absorption was studied, which evaluated β to be (24-106) cm/GW. In addition, the optical limiting behavior has been studied.

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Publication Date
Sat Dec 30 2023
Journal Name
Iraqi Journal Of Science
Simulation of Gaussian Pulses Propagation Through Single Mode Optical Fiber Using MATLAB
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Computer-aided modeling and simulation software programs are essential tools
to predict how an optical communication component, link, or network will function
and perform. This paper aims to investigate the various effects on pulses
propagation in optical transmission systems utilizing the MATLAB program.
Dispersion and Attenuation effects are explored. The simulation of Gaussian pulses
propagation through single mode optical fiber, simplifies the design of optical
communication system and make the design process more efficient, less expensive,
and faster.

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Publication Date
Thu Jun 30 2022
Journal Name
Iraqi Journal Of Laser
PDF Tunable Optical filters Using Etched Polarization Maintaining Fiber Hybrid Sagnac Interferometer
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: In modern optical communication system, noise rejection multiple access interference (MAI) must be rejected in dense access network (DAN). This paper will study the dual optical band pass and notch filters. They will be extracted with tunable FWHM using 10cm (PMF) with different cladding diameters formed with etching 125μm PMF after immersing it with 40% of hydrofluoric acid (HF). This fiber acts as assessing fiber to perform Sagnac interferometer with splicing regions that placed 12cm (SMF) for performing hybrid Sagnac interferometer that consists of Mach-Zehnder instead of Sagnac loop which is illuminated by using laser source with centroid wavelength of 1546.7nm and FWHM of 286 pm or 9 ns in the time domain. . Firs

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Publication Date
Mon Sep 16 2024
Journal Name
Journal Of Optics
Improvement Of The Efficiency Of Optical Sensors Of Polypyrrole Using Graphene Oxide
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This research explores the preparation of polypyrrole (PPy) using chemical oxidation and its enhancement with graphene oxide (GO) for optical sensor applications. PPy was synthesized by polymerizing pyrrole monomers with ferric chloride (Fe2Cl3) as the oxidant. The resulting PPy was then combined with GO to form a composite material, aiming to improve its electrical and optical properties. Polypyrrole nanofibers were obtained and after adding graphene oxide, the sensitivity increased. Characterization techniques including UV-Vis spectroscopy, DC conductivity measurements, Field Emission Scanning Electron Microscopy (FESEM) and response of photocurrent analysis were employed. The incorporation of GO into PPy resulted in a significant reducti

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Publication Date
Wed Apr 25 2018
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Using Approximation Non-Bayesian Computation with Fuzzy Data to Estimation Inverse Weibull Parameters and Reliability Function
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        In real situations all observations and measurements are not exact numbers but more or less non-exact, also called fuzzy. So, in this paper, we use approximate non-Bayesian computational methods to estimate inverse Weibull parameters and reliability function with fuzzy data. The maximum likelihood and moment estimations are obtained as non-Bayesian estimation. The maximum likelihood estimators have been derived numerically based on two iterative techniques namely “Newton-Raphson” and the “Expectation-Maximization” techniques. In addition, we provide compared numerically through Monte-Carlo simulation study to obtained estimates of the parameters and reliability function i

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Publication Date
Tue May 03 2022
Journal Name
Teikyo Medical Journal
Tooth agenesis and palatal dimensions associated with craniofacial deformity- Cone Beam Computed Tomography based study
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Cleft / palate is one of the common congenital deformities in craniofacial region, associated with different types of dental anomalies like (Tooth agenesis, impaction, and supernumerary teeth) with marked changes in palatal dimensions. This study aimed to determine the prevalence of teeth agenesis and dental anomalies in cleft lip/palate patients using CBCT, and to compare the palatal dimension of cleft group with control subjects. Twenty-eight cleft cases collected during the period from 2015 to 2022, CBCT images evaluated, the study sample classified into two groups (14 bilateral and 14 unilateral cleft lip/palate) and the non-cleft control group (14 CBCT images). The presence of dental anomalies was assessed in relation to clef

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Publication Date
Fri Jun 24 2022
Journal Name
Iraqi Journal Of Science
Measurement of Radon Concentration in Fly Ash Samples from Electric Power Stations in Iraq in The Middle & South by using Nuclear Track Detector CR-39
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In this study, concentrations of Radon were measured for fifty two samples of Fly Ash taken from five thermal power plants in the middle and south of Iraq [Al-Rashed, Al-Dura, Al-Musaeb, Al-Naserya, Al-Basrah (AlHaretha)].
The radon concentrations in samples measured by registrat alpha-emitting radon (222Rn) by using (CR-39) track detector, The concentrations values were calculated by a comparison with standard samples The results shows that the radon concentrations is between (91.931-30.645 Bq/m3)

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Publication Date
Thu Jan 17 2019
Journal Name
Energy Procedia
Irradiation of the thin films of MnS with fast neutrons and the possibility of using the new characteristics in optical detector
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The optical detectors which had been used in medical applications, and especially in radioactive treatments, need to be modified studied for the effects of radiations on them. This study included preparation of the MnS thin films in a way that vacuum thermal evaporation process at room temperature 27°C with thickness (400+-10nm) nm and a sedimentation rate of 0.39nm/sec on glass floors. The thin films prepared as a detector and had to be treated with neutron irradiation to examine the results gained from this process. The results decay X-ray (XRD) showed that all the prepared thin films have a multi-crystalline structure with the dominance of the direction (111), the two samples were irradiated with a neutron irradiation source (241Am-9Be)

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Publication Date
Fri Jul 01 2016
Journal Name
Journal Of Engineering
Determination of Mono-crystalline Silicon Photovoltaic Module Parameters Using Three Different Methods
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For modeling a photovoltaic module, it is necessary to calculate the basic parameters which control the current-voltage characteristic curves, that is not provided by the manufacturer. Generally, for mono crystalline silicon module, the shunt resistance is generally high, and it is neglected in this model. In this study, three methods are presented for four parameters model. Explicit simplified method based on an analytical solution, slope method based on manufacturer data, and iterative method based on a numerical resolution. The results obtained for these methods were compared with experimental measured data. The iterative method was more accurate than the other two methods but more complexity. The average deviation of

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Publication Date
Fri Apr 01 2022
Journal Name
Journal Of Engineering
Prediction of Shear Strength Parameters of Gypseous Soil using Artificial Neural Networks
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The shear strength of soil is one of the most important soil properties that should be identified before any foundation design. The presence of gypseous soil exacerbates foundation problems. In this research, an approach to forecasting shear strength parameters of gypseous soils based on basic soil properties was created using Artificial Neural Networks. Two models were built to forecast the cohesion and the angle of internal friction. Nine basic soil properties were used as inputs to both models for they were considered to have the most significant impact on soil shear strength, namely: depth, gypsum content, passing sieve no.200, liquid limit, plastic limit, plasticity index, water content, dry unit weight, and initial

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