This paper presents the effect of relativistic and ponderomotive nonlinearity on cross-focusing of two intense laser beams in a collisionless and unmagnetized plasma. It should be noted here that while considering the self-focusing due to relativistic electron mass variation, the electron ponderomotive density depression in the channel may also be important. Therefore/these two nonlinearties may simultaneously affect the self-focusing process. These nonlinearities depend not only on the intensity of one laser but also on the second laser. Therefore, one laser beam affects the dynamics of the second beam and hence the process of cross-focusing takes place. The electric field amplitude of the excited electron plasma wave (EPW) has been cal

In this work, the elemental constituents of smoker and nonsmoker
teeth samples of human were analyzed by Laser induced breakdown
spectroscopy method (LIBS). Many elements have been detected in
the healthy teeth samples, the important once are Ca, P, Mg, Fe, Pb
and Na. Many differences were found between (female and male)
teeth in Ca, P, Mg, Na and Pb contents. The concentrations of most
toxic elements were found significantly in the smoker group. The
maximum concentrations of toxic elements such as Pb, Cd and Co
were found in older male age above 60 year. Also, it was found that
the minimum concentrations of trace elements such as Ca, P and Na
exist in this age group. From these results it is clear that the

In this work, lead oxide nanoparticles were prepared by laser ablation of lead target immersed in deionized water by using pulsed Nd:YAG laser with laser energy 400 mJ/pulse and different laser pulses. The chemical bonding of lead oxide nps was investigated by Fourier Transform Infrared (FTIR); surface morphology and optical properties were investigated by Scanning Electron Microscope (SEM) and UV-Visible spectroscopy respectively, and the size effect of lead oxide nanoparticles was studied on its antibacterial action against two types of bacteria Gram-negitive (Escherichia coli) and Gram-positive (Staphylococcusaurus) by diffusion method. The antibacterial property results show that the antibacterial activity of the Lead oxide NPs was

Dielectric barrier discharges (DBD) can be described as the presence of contact with the discharge of one or more insulating layers located between two cylindrical or flat electrodes connected to an AC/pulse dc power supply. In this work, the properties of the plasma generated by dielectric barrier discharge (DBD) system without and with a glass insulator were studied. The plasma was generated at a constant voltage of 4 kV and fixed distance between the electrodes of 5 mm, and with a variable flow rate of argon gas (0.5, 1, 1.5, 2 and 2.5) L/min. The emission spectra of the DBD plasmas at different flow rates of argon gas have been recorded. Boltzmann plot method was used to calculate the plasma electron temperature (Te), and Stark broadeni

 Abstract Objective: Comparison of femtosecond small incision lenticule extraction (FS-SMILE) versus Femtosecond laser Insitu keratomileusis (FS-LASIK) regarding dry eye disease (DED) and corneal sensitivity (CS) after those refractive surgeries. Methods: A comparative prospective study conducted for a period of 2 years; from March 2017 until February, 2019. Enrolled patients were diagnosed with myopia. Fifty patients (100 eyes) were scheduled for bilateral FS-SMILE and the other 50 patients (100 eyes) had been scheduled for bilateral FS-LASIK. Both groups were followed for six months after surgery. The age, gender, and preoperative refraction for both groups were matched. Complete evaluation of dry eye disease had been

 Abstract Objective: Comparison of femtosecond small incision lenticule extraction (FS-SMILE) versus Femtosecond laser Insitu keratomileusis (FS-LASIK) regarding dry eye disease (DED) and corneal sensitivity (CS) after those refractive surgeries. Methods: A comparative prospective study conducted for a period of 2 years; from March 2017 until February, 2019. Enrolled patients were diagnosed with myopia. Fifty patients (100 eyes) were scheduled for bilateral FS-SMILE and the other 50 patients (100 eyes) had been scheduled for bilateral FS-LASIK. Both groups were followed for six months after surgery. The age, gender, and preoperative refraction for both groups were matched. Complete evaluation of dry eye disease had been

Abstract
The study was conducted in Baghdad and aimed to:
The impact of moving the educational activities in the conservation of literary
texts and the development of literary taste in the fifth grade students moral "by
verifying the validity of hypotheses Elsafreeten following forms:
The first hypothesis:
- There are no differences in women with statistical significance between means
of scores of students three experimental groups, the experimental group first
used upstream activities in the teaching material of literature and texts, the
second experimental group used the activities of building in the teaching
material itself and the experimental group the third use activities concluding
taught the same

The aim of this investigation is to study and analysis the role of governance in the evaluation of the and social performance of the economic units to be addressed through the concept of corporate governance and then to the social performance and its relationship to corporate governance.

The most important obtained results from this research is that the corporate governance of extreme importance, and derive their importance from being an essential tool to contribute to the transparency and fair disclosure of the financial results of economic units in the fight against financial and administrative corruption in economic units, thus providing protection and confidence of all parties, and the evaluating soci

The present study aimed at identifying the role of supervisory and training practices in the field   education program in achieving course objectives from the perspective of the student teachers in the Faculty of Science and Arts in sharourah, and its relationship to some variables (gender, specialization,estimation). To achieve this, the researcher used the descriptive-analytical method, and the study tool was designed, which consists of (24) items distributed on two axes: the objectives of field education and supervisory and training practices.Then, the study tool was applied to the research sample represented in the entire study community, which consists of (65) male and female students in the Faculty of Sciences and Arts in