The present work investigated the effect of distance from target surface on the parameters of lead plasma excited by 1064nm Q-switched Nd:YAG laser. The excitation was conducted in air, at atmospheric pressure, with pulse length of 5 ns, and at different pulse laser energies. Electron temperature was calculated by Boltzmann plot method based on the PbI emission spectral lines (369.03 nm, 416.98 nm, 523.48, and 561.94 nm). The PbI lines were recorded at different distances from the target surface at laser pulse energies of 260 and 280 mJ. The emission intensity of plasma increased with increasing the lens-to-target distance. The results also detected an increase in electron temperature with increasing the distance between the focal lens and the surface of the target in all laser energies under study. In addition, the electron number density was determined by using the Stark broadening method. The data illustrated that the electron number density was increased with increasing the distance from target surface, reaching the maximum at a distance of 11 cm for all pulse laser energy levels under study.
A Spectroscopic study has been focused in this article to study one of the main types of active galaxies which are quasars, and to be more precise this research focuses on studying the correlation between the main engine of Quasi-Stellar Objects (QSO), the central black hole mass (SMBH) and other physical properties (e.g. the star formation rate (SFR)). Twelve objects have been randomly selected for “The Half Million Quasars (HMQ) Catalogue” published in 2015 and the data collected from Salon Digital Sky survey (SDSS) Dr. 16. The redshift range of these galaxies were between (0.05 – 0.17). The results show a clear linear proportionality between the SMBH and the SFR, as well as direct proportional between the luminosit
... Show MoreInfluenza is a highly infectious and lethal viral disease, it appears on Earth periodically in connection with the passage of comet in the vicinity of Earth around the Sun .it is believed that particles spread from the tail of the comet due to solar heating energy ,are contaminated with very tiny small particles considered as viruses. Viruses reach the Earth with the power of the solar wind due to solar activity cycle which is driven every 11 year. Viruses pushed towards Earth’s atmosphere, then precipitate on clouds and reach the surface of Earth. These viruses are very well shielded and unaffected by even UV radiation ,but the only way the shell is melt when they passes through the digestive system . Results showed a good correlation
... Show MoreIn the current study, the emission spectra generated from clove were measured under normal atmospheric pressure with different laser energies. Clove is used as a source of essential oil in herbal medicine, in particular as a dynamic analgesic oil in dental and other diseases. For aromatherapy, Antiseptic, antiviral, and antimicrobial agents are also packaged with cloves. Compounds that reduce inflammation tend to battle sore throats, cold, and cough as they display so many advantages. The measured spectrum reveals distinctive lines of clove’s chemical elements. X-ray fluorescent (XRF) and atomic absorption spectrometry (AAS) were used to measure the spectrum generated or absorbed by detecting the presence of va
... Show MoreABSTRACT Background: This study aimed to study the effect of some acidic drinks (Vinegars and fresh Orange juice) and energy drinks (Red bull) on surface roughness of three types of bulkfill composite materials: Filtek posterior bulkfill (3M), Sonicfill (Kerr) and Filtek p60 (3M). Materials and Methods: Total number of 120 samples are prepared by using a mold of (12mm diameter and 3mm height), which were divided into three groups forty samples for each group: Group A: Filtek bulkfill posterior composite (3M), Group B: Sonicfill composite (Kerr), Group C: Filtek P60 (3 M) which then divided into four sub- groups (n=10) (1) samples were kept in distilled water as a control group (2) samples were immersed in Redbull (3) samples were immersed
... Show MoreCollapsible behaviour of soil is considered as one of the major problems in the stability of roadway embankment, the lack of cohesion between soil particles and its sensitivity to the change of moisture content are reasons for such problem. Creation of such cohesion may be achieved by implementation of liquid asphalt and introduction of Nano additives. In this work, silica fumes, fly ash and lime have been implemented with the aid of asphalt emulsion to improve the unconfined compressive strength of the collapsible soil. Specimens of 38 mm in diameter and 76 mm height have been prepared with various percentages of each type of Nano additive and fluid content. Specimens were subjected to unconfined compressive strength determination at dry a
... Show MoreHydrocarbon displacement at the pore scale is mainly controlled by the wetness properties of the porous media. Consequently, several techniques including nanofluid flooding were implemented to manipulate the wetting behavior of the pore space in oil reservoirs. This study thus focuses on monitoring the displacement of oil from artificial glass porous media, as a representative for sandstone reservoirs, before and after nanofluid flooding. Experiments were conducted at various temperatures (25 – 50° C), nanoparticles concentrations (0.001 – 0.05 wt% SiO2 NPs), salinity (0.1 – 2 wt% NaCl), and flooding time. Images were taken via a high-resolution microscopic camera and analyzed to investigate the displacement of the oil at dif
... Show MoreHydrocarbon displacement at the pore scale is mainly controlled by the wetness properties of the porous media. Consequently, several techniques including nanofluid flooding were implemented to manipulate the wetting behavior of the pore space in oil reservoirs. This study thus focuses on monitoring the displacement of oil from artificial glass porous media, as a representative for sandstone reservoirs, before and after nanofluid flooding. Experiments were conducted at various temperatures (25 – 50° C), nanoparticles concentrations (0.001 – 0.05 wt% SiO2 NPs), salinity (0.1 – 2 wt% NaCl), and flooding time. Images were taken via a high-resolution microscopic camera and analyzed to investigate the displacement of the oil
... Show MoreIn this study, hydroxyapatite (HAP, Ca10(PO4)6(OH)2) has been prepared as bioceramic material with biological specifications useful to used for orthopedic and dental implant applications. Wet chemical processing seems to form the fine grain size and uniform characteristic nanocrystalline materials by the interstice factors controlling which affected the grain size and crystallinity in order to give good mechanical and/or constituent properties similar as natural bone. Fluorinated hydroxyapatite [4-6 wt% F, (FHA, Ca10(PO4)6(OH)2–Fx] was developed in new method for its posses to increased strength and to give higher corrosion resistance in biofluids than pure HAP moreover reduces the risk of dental caries. The phase's and functional groups
... Show More