Due to the remarkable progress in photovoltaic technology, enhancing efficiency and minimized the costs have emerged as global challenges for the solar industry. A crucial aspect of this advancement involves the creation of solar cell antireflection coating, which play a significant role in minimizing sunlight reflection on the cell surface. In this study, we report on the optimization of the characteristics of CeO2 films prepared by pulsed laser deposition through the variation of laser energy density. The deposited CeO2 nanostructure films have been used as an effective antireflection coating (ARC) and light-trapping morphology to improve the efficiency of silicon crystalline solar cell. The film’s thickness increases as laser fluence increase. The refractive index of the antireflective film is measured as a function of laser fluence. The properties of CeO2 thin films’ were characterized by various techniques. X-ray diffraction measurements show the grown films were crystalline with cubic and hexagonal phases. The degree of crystallinity of the film increases with the increase in the laser fluence. Scanning electron microscope results reveal that the film’s morphology and film uniformity improved as the laser fluence increases. Raman shift of the CeO2 film as a function of laser energy density was investigated. Photovoltaic properties show that the conversion efficiency of the silicon solar cell increases from 8.37 to 14.04% after deposited with ARC CeO2 film at laser energy density of 76.39 J/cm2. The CeO2 films deposited at 76.39 J/cm2 laser pulse energy density have highest hydrophobicity among all the prepared samples.
Background: Acne is a common disorder experienced by adolescents and persists into adulthood in approximately 12%–14% of cases with psychological and social implications of high gravity. Fractional resurfacing employs a unique mechanism of action that repairs a fraction of skin at a time. The untreated healthy skin remains intact and actually aids the repair process, promoting rapid healing with only a day or two of downtime. Aims: This study, was designed to evaluate the safety and effectiveness of fractional photothermolysis (fractionated Er: YAG laser 2940nm) in treating atrophic acne scars. Methods: 7 females and 3 males with moderate to severe atrophic acne scarring were enrolled in this study that attained private clinic for Derm
... Show MoreAbstract
This research aims to assess the practice of physical activities by people with intellectual disabilities and its challenges during the Coronavirus (COVID-19) pandemic from their families' point of view. The research sample consisted of (87) individuals from families with intellectual disabilities in the Makkah region. The sample was selected by the simple random method where the researcher used the descriptive analytical approach. A questionnaire of (32) items was used as the research tool to collect data. The findings of the study showed that the assessment level of practicing physical activities by people with intellectual disabilities was low. The public facilities dimension ranked first with a moder
... Show MoreTwo Prototypes of Transversely Excited at atmospheric pressure (TEA) Nitrogen laser systems (One Stage Blumlein Circuit and Two Stage Blumlein Circuit) were fabricated and operated. High voltage power supply with variable operating voltage (0-20 kv) and operating current (1-3A) was built and tested successfully. The gas flow rate of 15 L/ min and 10 L/ min for OSBC and TSBC was used. The performance of the fabricated systems was studied extensively reaching to the optimum operating conditions. The obtained laser output energy for the first system has linear relationship with the applied voltage. The maximum output energy was about (1.14 mJ) with (10.40) ns pulse duration and the half-wave divergence angle was about (0.1455 m rad). In the
... Show MoreAir pollution is one of the important problems facing Iraq. Air pollution is the result of uncontrolled emissions from factories, car exhaust electric generators, and oil refineries and often reaches unacceptable limits by international standards. These pollutants can greatly affect human health and regular population activities. For this reason, there is an urgent need for effective devices to monitor the molecular concentration of air pollutants in cities and urban areas. In this research, an optical system has been built consisting of aHelium-Neonlaser,5mWand at 632.8 nm, a glass cell with a defined size, and a power meter(Gentec-E-model: uno) where a scattering of the laser beam occurs due to air pollution. Two pollutants were examin
... Show MoreTin oxide (Sn) nanoparticles were prepared by pulsed laser ablation (PLA) method at different laser energies (400-700mJ). (UV, XRD, AFM, SEM, EDS) methods were employed to determine the properties of nanomaterials. The optical properties showed that the energy gap decreased with increasing laser power; the structural properties showed the relationship between density and angle; Miller's coefficients for net angles were determined and the morphology properties showed the element's surface shape and surface roughness. Also, Tin oxide nanoparticles with added to Staphylococcus aureus bacteria isolated from the ear and cultured by striking method on nutrient agar to know the effect of tin oxide nanoparticles on the growth o
... Show MoreLaser assisted skin wound closure offers many distinct advantages over conventional closure
techniques. The objective of this in vitro experimental study, carried out at the Institute of Laser for
Postgraduate Studies/Baghdad University, was to determine the effectiveness of 980 nm diode laser in
welding of human skin wounds. Multiple 3-4 cm long full thickness incisions in a specimen of human
skin obtained from the discarded panniculus of an Abdominoplasty operation were tried to be laser
welded using a 4 mm spot diameter laser beam from a 980 nm diode laser at different laser parameters
and modes of action. The tensile strength at the weld site was analyzed experimentally. Although laser
assisted wound welding did
In this work, electron number density calculated using Matlab program code with the writing algorithm of the program. Electron density was calculated using Anisimov model in a vacuum environment. The effect of spatial coordinates on the electron density was investigated in this study. It was found that the Z axis distance direction affects the electron number density (ne). There are many processes such as excitation; ionization and recombination within the plasma that possible affect the density of electrons. The results show that as Z axis distance increases electron number density decreases because of the recombination of electrons and ions at large distances from the target and the loss of thermal energy of the electrons in high distance
... Show Moreto evaluate the effect of various Nd:YAG frequency doubled laser parameters on the acid
dissolution and the progression of in vitro caries like lesions in human enamel.
Materials and Methods: Human extracted caries free upper first premolar teeth were collected for
this study. The irradiated teeth were divided into two groups. The first group was irradiated with
continuous Nd:YAG laser radiation, and the second group was irradiated with chopped Nd:YAG laser
radiation. For the first group, power and exposure time were changed while for the second group
power and number of pulses were changed. The spot diameter was kept constant for all the samples.
Results: using 1.5 W and 3 seconds (exposure time), best results among
Urinary stones are one of the most common painful disorders of the urinary system. Four new technologies have transformed the treatment of urinary stones: Electrohydraulic lithotripsy, ultrasonic lithotripsy, extracorporeal shock wave lithotripsy, and laser lithotripsy.The purpose of this study is to determine whether pulsed holmium laser energy is an effective method for fragmenting urinary tract stones in vitro, and to determine whether stone composition affects the efficacy of holmium laser lithotripsy. Human urinary stones of known composition with different sizes, shapes and colors were used for this study. The weight and the size of each stone were measured. The surgical laser system which used in our study is Ho:YAG laser(2100nm)
... Show MoreIn this paper we report the use of supersonic jet laser induced fluorescence (LIF) spectroscopy to facilitate the study of the spectra of some organometallic sandwich compounds particularly the metallocenes. The charge-transfer processes within these compounds, especially ligand to metal charge transfer within decamethylrhenocene ( - C5 Me5)2 Re were of particular interest. The spectrum shows a high degree of structures, indicating that there are several levels populated and these molecules are able to undergo many possible transitions