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.
To study the response of the celery plant to nitrogen fertilization and spray with salicylic acid in the leaves content of nutrients, the research was conducted in one of the fields of the Department of Horticulture and Gardening Engineering / College of Agriculture / University of Baghdad within the 2019-2018 season. The research was carried out as a global experiment and with the design of complete randomized sectors (RCBD) and with three replicates, the first factor included the addition of nitrogen with three levels and its symbol (N) (N1 control), (N2) g / m2 18 ), (N3) 37 g / m2 and the second factor spraying acid salicylic is denoted by
The anatomical study of the epidermis leaflet for seven species and variety wild belonging to the genus Medicago L. species are: M. constricta Dur., M. coronata L., M. intertexta L., M. intertexta.var. ciliaris L., M. laciniata L., M. lupulina L., M. minima L. and M. sativa L. were studied, The search included epidermis characters and stomatal complexes addition to venation system in leaflets. It is revealed through the study, epidermis leaflet type Amphistomatic (the stomata spread on the upper and lower surface) as well as the presence of three types of stomatal complexes namely: Anisocytic (the guard cells surrounded by three unequal cell size), Anomocytic (not differential from subsidiary cells in epidermis) and Anomotetracytic (four ce
... Show MoreThe purpose of my thesis is to prepare four new ligands (L1-L4) that have been used to prepare a series of metal complexes by reacting them with metal ions: M=(Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II) Where succinyl chloride was used as a raw material for the preparation of bi-dented ligands (L1-L4) by reacting it with potassium thiocyanate as a first step and then reacting with (2-aminobenzothiazole, Benzylamine, 4-aminoantipyrine, Sulfamethoxazole) respectively as a second step with the use of dry acetone as a solvent, the chemical formula of the four ligands prepared in succession: N1,N4-bis(benzo[d]thiazol-2-ylcarbamothioyl)succinamide (L1) N1,N4-bis(benzylcarbamothioyl)succinami
... Show MoreThis study investigates the impact of agricultural investment policy—represented by agricultural loans and investment allocations—on rice crop production in Iraq over the period 2003–2023, employing the Autoregressive Distributed Lag (ARDL) model. Using time-series econometric analysis, the study confirms a short-term positive and statistically significant effect of financial support on rice output, while revealing statistically insignificant long-term effects. The presence of a cointegration relationship suggests long-term equilibrium between agricultural policy variables and rice production. However, the absence of causality in the Yamamoto-Toda test implies that structural and institutional inefficiencies may dilute the long-term i
... Show MoreBackground: Irritable bowel syndrome (IBS) is a functional bowel syndrome with discomfort and changed bowel habits in the absence of obvious structural abnormalities. It is more common among adolescents and young age groups. Aim: Aims of the study is to identify the prevalence of Irritable Bowel Syndrome among medical students of AL- Kindy College of medicine, and to Exploring the effect on IBS prevalence of general demographic form to observe the association between anxiety and IBS. Data were collected on a sample of University of Baghdad, Al-Kindy College of Medicine students in Baghdad, Iraq. The study was conducted over a period for 6 months From December 2020 to June 2021. This study enrolled 250 students who were selected rand
... Show MoreABSTRACT
Background : The aim of this work is to assess the role of breast sonography and ductography in the evaluation of different causes of nipple discharge.
Methods : The study will be carried out on twenty-five female patients referred to the Radiodiagnosis department at Alexandria Main University Hospital presenting with nipple discharge.
They were divided into two groups:
Group I include 10 patients (40%) with surgically significant nipple discharge who were the patients with unilateral, uniorificial surgically significant colour type nipple discharge .They were investigated by mammography, sonography, and ductography.
Group II include 15 patients
... Show MoreThis research is represented by exploring the experience of "the theater of the oppressed" by (Augusto Boal) as an experiment that represents a different aesthetic pattern in the presentation of theatrical performance which is in contrast with the Aristotelian and Brechtian patterns, and as a result of the increasing problems of the individual in societies according to his needs and an attempt to express the suffering of human and the loss of his rights in general.
The research also tries to uncover the power of identification and the alienation of existence in the theater of the oppressed as that power, with its diversity of legal, legitimate, religious, political, economic and social capabilities has become a burden instead of being
This paper presents an experimental and numerical study which was carried out to examine the influence of the size and the layout of the web openings on the load carrying capacity and the serviceability of reinforced concrete deep beams. Five full-scale simply supported reinforced concrete deep beams with two large web openings created in shear regions were tested up to failure. The shear span to overall depth ratio was (1.1). Square openings were located symmetrically relative to the midspan section either at the midpoint or at the interior boundaries of the shear span. Two different side dimensions for the square openings were considered, mainly, (200) mm and (230) mm. The strength results proved that the shear capacity of the dee
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