When employing shorter (sub picosecond) laser pulses, in ablation kinetics the features appear which can no longer be described in the context of the conventional thermal model. Meanwhile, the ablation of materials with the aid of ultra-short (sub picosecond) laser pulses is applied for micromechanical processing. Physical mechanisms and theoretical models of laser ablation are discussed. Typical associated phenomena are qualitatively regarded and methods for studying them quantitatively are considered. Calculated results relevant to ablation kinetics for a number of substances are presented and compared with experimental data. Ultra-short laser ablation with two-temperature model was quantitatively investigated. A two-temperature model for the description of transition phenomena in a non-equilibrium electron gas and a lattice under picosecond laser irradiation is proposed. Some characteristics are hard to measure directly at all. That is why the analysis of physical mechanisms involved in the ablation process by ultra-short laser pulses has to be performed on the basis of a theoretical consideration of `indirect' experimental data. For Copper and Nickel metal targets, the two-temperature model calculations explain that the temperature of the electron subsystem increased suddenly and approached a peak value at the end of laser pulse. In addition, the temperature profile of lattice temperature subsystem evolution slowly, and still increasing after the end of laser pulse. A good agreement prevails when a comparison between the present results and published results.
Praise be to God alone, and after:
This is a research entitled: “A fundamental study of judicial jurisprudence rules and their applications in the Hanbali school of thought,” in which the researcher studied eight legal jurisprudential rules considered by the Hanbalis and others.
At the conclusion of his research, the researcher reached a number of results, including: the importance of taking care of judicial rules, and the need for judges and their assistants to them, including: the need for students of science in Hanbali jurisprudence to study these rules according to the doctrine, and to highlight their applications to them, including: the importance of the rules under study, and their impact on rulings Jurisprudenc
... Show MoreIn a common language based on interpretation and diagnosis in the symbols and signs, the subject of Sufism and artistic semiotics is manifested in the construction and intensity of the reading of the text and the dismantling of its intellectual systems.
The emergence of Sufism in its religious features and the spiritual revelations related to the divine love of life in absolute reality, And images and language in a stream of intellectual and artistic unique and harmonious communicates with the subject of the themes of the Arab literature and its implications, but it is separated by a special entity signals and symbols related to the mysticism and worship.
The unleashing of the imagination and the diagnosis,
Vascular plants that have been identified during the study seasons in the Island. The cultivated plants were 126 species belong to 103 genera and to 49 families of the year 2001-2002 . The natural vegetation in this Island has been subjected to a total disturbance and subsidence due to the comprehensive turbidity of the Island environment.Number of names of that natural vegetation has been mentioned in the study within the weed plants.The results of the study of the period of flowering and their attitudes show clear seasonal differences. During the cold months of winter, the number of the cultivated and the natural plants was at the rate of 15%.These kinds of flowers require high level of care to increase their numbers. While in the spring
... Show MoreThe aim of this study is to get practical evidence from the Egyptian business environment The Impact of Audit Committees Effectiveness and External Audit Quality on Timeliness of annual Financial Report. Design and methodology: The study based on the content analysis technique to examine the annual reports of a sample of (30) companies listed on the Egyptian Stock Exchange (EGX100) during the period (2016-2019) with a total of (120) respondents. To test the research hypotheses, the results of the study indicate that there is a negative significant impact of audit committees on timeliness of annual financial report. Moreover, while there is a negative impact on the quality of the external audit on the timing of issuing the annual
... Show MoreObesity is a disease describe a case of excessive accumulation of body fats. Obesity is linked to the morbidity of human health, such as the development of hypertension. The study designed to investigate the levels of glucose, urea, creatinine, and lipid profile parameters in sera of obese female and hypertensive obese female. The study included 90 subjects who divided onto three groups equally, in which they are healthy control, normotensive obese, and hypertensive obese. A significant elevation (P<0.01) has observed in the level of glucose, urea, creatinine, triglycerides (TGs), cholesterol, LDL-C, and VLDL-C in obese females compared with control, yet only TGs and VLDL-C were si
KE Sharquie, JR Al-Rawi, AA Noaimi, HM Al-Hassany, Journal of drugs in dermatology: JDD, 2012 - Cited by 47
In this report Silver doped Tin Sulfide (SnS) thin films with ratio of (0.03) were prepared using thermal evaporation with a vacuum of 4*10-6 mbar on glass with (400) nm thickness and the sample annealing with ( 573K ). The optical constants for the wavelengths in the range (300-900) nm and Hall effect for (SnS and SnS:3% Ag) films are investigated and calculated before and after annealing at 573 K. Transition metal doped SnS thin films the regular absorption 70% in the visible region, the doping level intensification the optical band gap values from 1.5- 2 eV. Silver doped tin sulfide (SnS) its direct optical band gap. Hall Effect results of (SnS and SnS:3% Ag) films show all films were (p-type) electrical conductivity with resistivity of
... Show MoreIron oxide(Fe3O4) nanoparticles of different sizes and shapes were synthesized by solve-hydrothermal reaction assisted by microwave irradiation using ferrous ammonium sulfate as a metal precursor, oleic acid as dispersing agent, ethanol as reducing agent and NaOH as precipitating agent at pH=12. The synthesized Fe3O4 nano particles were characterized by X-ray diffraction (XRD), FTIR and thermal analysis TG-DTG. Sizes and shapes of Fe3O4 nanoparticles were characterized by Scanning Electron Microscopy (SEM), and atomic force microscopy (AFM).