The growing demand for optical fibers is due to their superior the ability to transmit information with high efficiency and minimal loss across extensive distances. In this study, four optical fibers with core radii ranging from (2.05-5.05) μm, and with a numerical aperture of 0.1624 were analyzed. The modal properties of these fibers were calculated at a wavelength of 1030 nm using the RP Fiber Calculator software (free version 2025). Furthermore, the impact of increasing the core radius on these properties was examined. The results showed that multimode fibers are formed when the core radius is much larger than the wavelength used. In contrast, single-mode fiber is obtained when this condition is not met. Five modes properties were calculated: cut-off wavelength, effective area, power in the core, propagation constant and effective refractive index. The geometric distribution of the amplitudes of all modes was graphically represented.
Abstract Background: Crown lengthening is a surgical procedure that apically positions the gingival edge and/or removes supporting bone in order to increase the amount of supra gingival tooth structure for restorative or cosmetic purposes.
The objective of the study: The purpose of this study was to evaluate the efficacy of the 940nm diode laser in esthetic crown lengthening surgery through clinical observations, patient questionnaires, clinical photographs, and gingival healing following gingival operations. Material and methods: In this randomized clinical trial, 16 patients (11 females and 5 males) had their crowns surgically lengthened using a diode laser (940 nm) in continuou
... Show MoreCopper oxide thin films were deposited on glass substrate using Successive Ionic Layer Adsorption and Reaction (SILAR) method at room temperature. The thickness of the thin films was around 0.43?m.Copper oxide thin films were annealed in air at (200, 300 and 400°C for 45min.The film structure properties were characterized by x-ray diffraction (XRD). XRD patterns indicated the presence of polycrystalline CuO. The average grain size is calculated from the X-rays pattern, it is found that the grain size increased with increasing annealing temperature. Optical transmitter microscope (OTM) and atomic force microscope (AFM) was also used. Direct band gap values of 2.2 eV for an annealed sample and (2, 1.5, 1.4) eV at 200, 300,400oC respect
... Show MoreThis study was carried out to determine the effects of some environmental variables on biodiversity index value of benthic invertebrates' community in samples that collected monthly from two adjacent sites nearby the confluence of Tigris and Diyala rivers within Baghdad city that’s from November 2007 - October 2008. Results showed differences in chemical and physical characteristics for each river. Where the annual averages of these characteristics in Rivers Tigris and Diyala respectively for: water temperature (20, 19) Cº, pH (8, 8), Dissolved oxygen DO(8,4 ) mg/l , EC(1152,2979)µc/cm , Turbidity (28,74) NTU, Total Hardness of CaCO3 (485,823)mg/l, and finally NO3 (4,6)mg/l. Concerning the biological groups, included types of Insect
... Show MoreFluorescent proteins (FPs) have revolutionised the life sciences, but the chromophore maturation mechanism is still not fully understood. Here we photochemically trap maturation at a crucial stage and structurally characterise the intermediate.
This work describes an experimental setup to evaluate the photodynamictoxicity of 650 nm diode laser and 532 nm Frequency-doubled Q-Switched Nd:YAG laser on the growth of Candida albicans as well as the potential fungicidal effect when combining the laser irradiation with specific photosensitizers namely methylene blue, toluidine blue, acridine orange and safranin O. In this study the findings showed that the number of colony-forming units per millilitre (CFU/ml) of C. albicans decreased with increasing exposure time. In particular in the case of the frequency doubled Nd:YAG laser combined with safranin O, the best lethal effect occurred at 11 minutes exposure time with 2.26 J/cm² energy density (89.18% reduction) in comparison with the
... Show MoreThe aim of this research is to employ starch as a stabilizing and reducing agent in the production of CdS nanoparticles with less environmental risk, easy scaling, stability, economical feasibility, and suitability for large-scale production. Nanoparticles of CdS have been successfully produced by employing starch as a reducing agent in a simple green synthesis technique and then doped with Sn in certain proportions (1%, 2%, 3%, 4%, and 5%).According to the XRD data, the samples were crystallized in a hexagonal pattern, because the average crystal size of pure CdS is 5.6nm and fluctuates in response to the changes in doping concentration 1, 2, 3, 4, 5 %wt Sn, to become 4.8, 3.9, 11.5, 13.1, 9.3 nm respectively. An increase in crystal
... Show MoreHemorrhoids are one of the most common surgical conditions. The hemorrhoid may cause symptoms that are: bleeding, pain, prolapse, itching, spoilage of feces, and psychologic discomfort. There are many methods for treatment of hemorrhoid like, medical therapy, rubber band ligation, electerocoagulation, stapled hemorrhoidpexy, photocoagulation, sclerothereapy, doppler guided artery ligation, Cryosurgery, and surgery. All methods for treatment of hemorrhoids have advantages, disadvantages, and limitations. Conventional haemorrhoidectomy was the traditional operation for the treatment of hemorrhoids. But recently other modalities of treatment had been used as an alternative operations including CO2 laser haemorrhoidectomy. This work aims to
... Show MoreThis paper comprises the design and operation of mono-static backscatter lidar station based on a pulsed Nd: YAG laser that operates at multiple wavelengths. The three-color lidar laser transmitter is based on the collinear fundamental 1064 nm, second harmonic 532 nm and a third harmonic 355nm output of a Nd:YAG laser. The most important parameter of lidar especially daytime operations is the signal-to-noise ratio (SNR) which gives some instructions in designing of lidar and it is often limit the effective range. The reason is that noises or interferences always badly affect the measured results. The inversion algorithms have been developed for the study of atmospheric aerosols. Signal-to-noise ratio (SNR) of three-color channel re
... Show MoreBaTiO3 thin films have been deposited on Si (111) and glass substrates by using pulsed laser deposition technique. The films were characterized by using X-ray diffraction, atomic force microscope and optical transmission spectra. The films growth on Si after annealing at 873K showed a polycrystalline nature, and exhibited tetragonal structure, while on glass substrate no growth was noticed at that temperature. UV-VIS transmittance measurements showed that the films are highly transparent in the visible wavelength region and near-infrared region for sample annealing on glass substrate. The optical gap of the film were calculated from the curve of absorption coefficient (αhν) 2 vs. hν and was found tobe 3.6 eV at substrate temperature 5
... Show MoreThe real and imaginary part of complex dielectric constant for InAs(001) by adsorption of oxsagen atoms has been calculated, using numerical analysis method (non-linear least square fitting). As a result a mathematical model built-up and the final result show a fairly good agreement with other genuine published works.