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 calculated. Comparison of the theory with the recent experimental observations has also been presented.
The behavior and shear strength of full-scale (T-section) reinforced concrete deep beams, designed according to the strut-and-tie approach of ACI Code-19 specifications, with various large web openings were investigated in this paper. A total of 7 deep beam specimens with identical shear span-to-depth ratios have been tested under mid-span concentrated load applied monotonically until beam failure. The main variables studied were the effects of width and depth of the web openings on deep beam performance. Experimental data results were calibrated with the strut-and-tie approach, adopted by ACI 318-19 code for the design of deep beams. The provided strut-and-tie design model in ACI 318-19 code provision was assessed and found to be u
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Most universities in the world are largely committed to creating credible and transparent admission standards that provide justice in admission and have the ability to predict students' performance in their chosen programs. Hence, this study aimed to reveal the predictive ability of the acceptance criteria for the level of performance of master's students in the College of Education at Sultan Qaboos University. Quantitative data were collected from (115) students' admission documents for those accepted in the postgraduate programs for the academic year 2019-2020, and GPA data was collected from students’ transcripts for the fall semester of 2019. Qualitative data were also collected from the interviews
... Show MoreDC glow discharges were generated between a thin cylindrical anode and a flat cathode, streamers are thought to propagate by photo-ionization; the parameters of photo-ionization depend on the He: CO ratio. Therefore we study streamers in He ( 90%, 80% and 70% ) with (10%, 20% and 30%) CO respectively. The streamer diameter is essentially the change by increase for similar voltage and pressure in all He-CO mixtures.
Abstract This research scrutinizes the impact of external magnetic field strength variations on plasma jet parameters to enhance its performance and flexibility. Plasma jets are widely used for their high thermal and kinetic energy in both medical and industrial fields. The study employs optical emission spectroscopy to measure electron temperature, electron density, and plasma frequency in a plasma jet subjected to varying magnetic field strengths (25, 50, 100, 150, and 250 mT). The results indicate that a stronger magnetic field results in higher electron temperature (1.485 to 1.991 eV), electron density (5.405 × 1017 to 7.095 × 1017), and plasma frequency 7.382 × 1012 to 8.253 × 1012 Hz. As well as the research investigates the influ
... Show MoreBackground Cardiovascular disease (CVD) is a leading cause of death worldwide. Ischemic heart disease is a major cause of morbidity and mortality. Lack of blood supply to the brain can cause tissue death if any of the cerebral veins, carotid arteries, or vertebral arteries are blocked. An ischemic stroke describes this type of event. One of the byproducts of methionine metabolism, the demethylation of methionine, is homocysteine, an amino acid that contains sulfur. During myocardial ischemia, the plasma level of homocysteine (Hcy) increases and plays a role in many methylation processes. Hyperhomocysteinemia has only recently been recognized as a major contributor to the increased risk of cardiovascular disease (CVD) owing to its eff
... Show MoreDiamond-like carbon, amorphous hydrogenated films forms of carbon, were pretreated from cyclohexane (C6H12) liquid using plasma jet which operates with alternating voltage 7.5kv and frequency 28kHz. The plasma Separates molecules of cyclohexane and Transform it into carbon nanoparticles. The effect of argon flow rate (0.5, 1 and 1.5 L/min) on the optical and chemical bonding properties of the films were investigated. These films were characterized by UV-Visible spectrophotometer, X-ray diffractometer (XRD) Raman spectroscopy and scanning electron microscopy (SEM). The main absorption appears around 296, 299 and 309nm at the three flow rate of argon gas. The value of the optical energy gap is 3.37, 3.55 and 3.68 eV at a different flow rate o
... Show MoreObjectives: To assess the changes in blood vessel stiffness and digital pulse wave amplitude because of flowmediateddilatation, and to explore how these two variables change when endothelial dysfunction isexperimentally induced.Method: The experimental study was conducted at the departments of physiology at the College of Medicine,Mustansiriyah University, and the College of Medicine, Al-Iraqia University, Baghdad, Iraq, from October 14, 2021, toMay 31, 2022, and comprised healthy young males who were subjected to the flow-mediated dilatation techniqueon the left brachial artery. Pulse transit time and the amplitude of the digital pulse wave were measured duringreactive hyperaemia for 2.5 minutes from the left middle finger using a
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The research aims to define the theoretical framework for corporate governance and its mechanisms and shed light on corporate governance in Iraq as well as the theoretical framework for the quality of financial reports and their relationship and the role of corporate governance in activating them. A commercial bank as a sample for the research, and a survey list was prepared to show the extent to which the research sample banks are committed to applying internal governance mechanisms. imposed on them by the local environment, which leads to improving the quality of financial reports for these banks.
I found that it does not meet some of the requirements, including browsing and organizing structural elements, which is something in which the researcher found a scope for research, and from here she can formulate the problem of her research with the following question: Is there an actual need to develop user interface designs in the websites of Iraqi colleges of fine arts? The research included four chapters (the first chapter - the research problem - the second chapter (theoretical framework), which included three sections, the first is to identify the user interface, the second topic is the structural elements, and the third topic includes the rules of interface design and the dimensions of interaction), as well as the third chapter i
... Show MorePurpose – determine the impact of the promotional mix in achieving competitive advantage in industrial organizations.
Problem- indicated a clear deficiency in employing the dimensions of the marketing mix in ensuring a competitive advantage for the researched organization.
Design/methodology/approach – Al-Dora Refinery was selected as a field of application. The sample was chosen by an intentional sample of (143) individuals in the Human Resources departments. The questionnaire was adopted as a data acquisition tool that was prepared based on a set of ready-made standards after being subjected to a number of v
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