This study investigates the surgical and thermal effects on oral soft tissues produced by CO2 laser emitting at 10.6 micrometers with three different fluences 490.79, 1226.99 and 1840.4 J/cm2. These effects are specifically; incision depth, incision width and the tissue damage width and depth. The results showed that increasing the fluence and /or the number of beam passes increase the average depths of ablation. Moreover, increasing the fluence and the number of beam passes increase the adjacent tissue damage in width and depth. Surgeons using CO2 laser should avoid multiple pulses of the laser beam over the same area, to avoid unintentional tissue damage.
The creation and characterization of laser-generated plasma are affected by laser irradiance, representing significant phenomena in many applications. The present work studied the spectroscopy diagnostic of laser irradiance effect on Zn plasma features created in the air by a Q-switched Nd: YAG laser at the fundamental wavelength (1064nm). The major plasma parameters (electron temperature and electron density) have been measured using the Boltzmann plot and the Stark broadening methods. The value of electrons temperature ranged from 6138–6067 K, and the electron density in the range of 1.4×1018 to 2×1018 cm-3, for laser irradiance range from 2.1 to 4.8×108 (W/cm2
... Show MoreThe laser micro-cutting process is the most widely commonly applied machining process which can be applied to practically all metallic and non-metallic materials. While this had challenges in cutting quality criteria such as geometrical precision, surface quality and numerous others. This article investigates the laser micro-cutting of PEEK composite material using nano-fiber laser, due to their significant importunity and efficiency of laser in various manufacturing processes. Design of experiential tool based on Response Surface Methodology (RSM)-Central Composite Design (CCD) used to generate the statistical model. This method was employed to analysis the influence of parameters including laser speed,
... Show MoreBackground: It is well known that the low level laser irradiation has act on immune system cells in a number of ways, one of them includes increasing phagocytic activity of irradiated cells. This study was established to shed light on the possible effect of laser irradiation on phagocytic activity of polymorphoneutrophils.
Subjects and methods: Fresh blood samples were obtained from twenty healthy volunteers for phagocytosis assay. The polymorphoneutrophils were isolated from blood and examined their phagocytic capacity befor and after exposure to laser irradiation.
Results: The present study revealed a significant increase in the mean percentage of phagocytosis after exposure to diode laser of wave le
Thi s study included the effect of chronic exposure of di fferent concentrations of Nan on the biology of fresh water zroDplonk ton species Moina 41.112' ( Cladcxe'ra The concentrations used for chronic exposure were 03, 0.75. 1 960 to investigate iI effects on the life cycle and la lables of this species after exposure period and the range of this exposure effects on the rate of expectation for further life, also the effect of salinity on reproduotive parameters was studied which included average of total number of eggs and young produced, volume clutch's (6.95. indiclutch for control group , 14.516 indi clutch for 0.596a ,3_65 ind./ clutch for (175 5(.. and 03 Ind} cruel] for 1960) and number of Clutch's (5.5 clutch/ female for control gr
... Show MoreAl-Qudis power plant was chosen, as one of the power stations of Baghdad, to investigate the effects of Cadmium that emitted from combustion of crude oil in that power plant on the workers' glutathione serum level. Air samples were taken seasonally during August 2011- July 2012 from four sites at Al- Qudis power plant which are oil treatment unit 1(site 1), oil treatment 2 (site2), pre –chimney 1(site 3) and pre-chimney 2 (site 4), to measure levels of heavy metal (cadmium) under study. Blood samples were collected from the workers to estimate the heavy metal Cadmium. Air cadmium levels during summer (August and September) were varied from 6.26 ± 0.6 μg/m3 at site 1 to 6.89 ± 0.67 μg/m3 at site 3, while in spring (end of March, and
... Show MoreAl-Qudis power plant was chosen, as one of the power stations of Baghdad, to investigate the effects of Cadmium that emitted from combustion of crude oil in that power plant on the workers' glutathione serum level. Air samples were taken seasonally during August 2011- July 2012 from four sites at Al- Qudis power plant which are oil treatment unit 1(site 1), oil treatment 2 (site2), pre –chimney 1(site 3) and pre-chimney 2 (site 4), to measure levels of heavy metal (cadmium) under study. Blood samples were collected from the workers to estimate the heavy metal Cadmium. Air cadmium levels during summer (August and September) were varied from 6.26 ± 0.6 μg/m3 at site 1 to 6.89 ± 0.67 μg/m3 at site 3, while in spring (end of March, and
... Show MoreThis research aims to identify the effect of numbered heads strategy on developing oral expression skills among fifth-grade primary students in Bisha Province. To achieve this, the researcher prepared a research tool represented in the observation card which consists of (27) statements distributed in four axes. The tool was sent to (5) experts in the field to verify their validity. In light of their corrections, the tool was developed to be valid for gathering field information. To verify the validity of the content and the reliability of the tool, the researcher applied it to a sample consists of (20) students from outside the research group. The overall coefficient of correlation between the statements of the tool is as follows: (.95,
... Show MoreIn this study, plastic wastes named (PET and PVC) were used to prepare polymer matrix composite (PMC) which can be used in different applications. Composite materials were prepared by mixing unsaturated polyester resin (UP) with plastic wastes, two types of plastic waste were used in this work included polyethylene-terephthalate (PET) and Polyvinyl chloride (PVC) with various weight fractions (0, 5,10,15, 20 and 25%) added as a filler in flakes form. In this work, some of the tests that were carried out included (tensile, bending, and compressive strength) as mechanical tests, in addition to (thermal conductivity and water absorption) as physical tests. The values of tensile, compressive strength and Young's modulus of UP increased after
... Show MorePseudomonas aeruginosa, a ubiquitous environmental organism, is a difficult-to-treat opportunistic pathogen due to its broad-spectrum antibiotic resistance and its ability to form biofilms. In this study, we investigate the link between resistance to a clinically important antibiotic, imipenem, and biofilm formation. First, we observed that the laboratory strain P. aeruginosa PAO1 carrying a mutation in the oprD gene, which confers resistance to imipenem, showed a modest reduction in biofilm formation.We also observed an inverse relationship between imipenem resistance and biofilm formation for imipenem-resistant strains selected in vitro, as well as for clinical isolates.We identified two clinical isolates of P. aeruginosa from the sputum
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