In this research we study the effect of UV radiation on pure PC samples and doped samples with plasticizer (DOP) for different exposure times (6, 12, 18, 24h). The study have been made on the change in the IR spectra causes by the UV radiation on both kinds of samples, besides the morphology changes were also studied by the optical microscope. From the results we conclude that the increasing of exposure causes the elaboration of CO2 and C2 gases.
The military presence in the Gulf region after the British withdrawal from it in 1971 was one of the most important pillars of the American strategy to climb the ladder of global leadership, as the geostrategic features that the region enjoyed provided factors of controlling energy sources and global trade routes. The United States of America guarantees Western Europe and Japan the process of access to energy sources and the exclusion of its opponents from the region, especially the Soviet Union, and the growing American military presence in the Gulf after the invasion of Iraq in 2003. On the other hand, the region experiences many contradictions, some of which threaten its security, such as the exacerbation of disputes between its count
... Show MoreThe present paper deal with the issue of the beginning of the culturally
renaissance in emirates of Arab Gulf from 1914-1945 between tow world war
has been attracting the attention of academic about the developments in many
fields in the Arab Gulf at this time.
The paper is divided into five sections. First section, deals with the
geographic importance for the Arab Gulf region. Second section, the economic
situations in the region before and after oil. The third section, talk for social
situations, like population, tribe and tribes in society, and immigration. The
fourth section, deals with the factors of rise the culture and political in the Arab
Gulf before discovery of oil period. The five section, the cultu
Background: This study was performed to determine the effect of aging of different types of composite material restorations on: Shear bond strength (SBS) to light cure and no mix chemical cure orthodontic adhesives with sapphire bracket and the debonding failure sites. Materials and methods: One hundred forty four composite disks were made from three different composite resin materials which are: 3M Filtek Z250, 3M filtek Z350 and 3M Valux plus, each group with (48) disks each, then according to the duration of storage each group was subdivided into two equal groups one of them stored for one day and the other was stored for one month, then each group was further subdivided into two equal subgroups with (12) disks each one bonded with ligh
... Show MoreA solid Phase Extraction (SPE) followed by HPLC-UV method is described for the simultaneous quantitative determination of nine priority pollutant phenols : Phenol, 2- and 4-Nitrophenol, 2,4-Dimethylphenol, 2-, 2,4-Di-, 2,4,6-Tri-, and Penta- chlorophenol, 4 Chloro-3-methylphenol. The phenols were separated using a C-18 column with UV detector at wave length of 280nm. The Flow of mobile phase was isocratic consisted of 50:50 Acetonitrile: phosphate buffer pH=7.1, column temperature 45 C°, Flow Rate 0.7 ml/min. Calibration curves were linear (R2 = 0.9961-0.9995). The RSDs (1.301-5.805)%, LOD(39.1- 412.4) µg/L, LOQ(118.5-1250.8) µg/L, the Robustness (1.55-4.89), Ruggedness (2.82-4.00), Repeatability (2.1-4.95), Recoveries%
... Show MoreThe complexation between folic acid and a typical polyaromatic hydrocarbon, fluorene, was investigated using FTIR and UV spectra. Appearance of a new IR band at 2401cm−1 demonstrates that NH2–C=N moiety on pterin ring in folic acid is protonated when fluorene is introduced. The emergence of two charge transfer bands at 217 nm and 278 nm in UV difference spectra shows the presence of π-π complexation between folic acid and fluorene. These experiments confirm that fluorene could combine with the pterin ring of folic acid through π-π donor–acceptor interaction and induce the protonation process in folic acid upon strengthening electron accepting ability of pterin ring. The results suggest that complexatio
... Show MoreThe study of Stress- Strain relation for novolac reinforced by qujurate plant was carried out before and after the immersing in boiled water at 100C0 . It was found that the compression strength and surface hardness decreased when the composites immersed in boiled water for long times.
Q-switched lasers widely used in management skin diseases and
sometimes its effect may be inadequate or associated with
cytotoxicity. The current study aimed to investigate the effect of
Q-switched Nd:YAG laser upon cellular elements using in vitro
experimental model. Aqueous solutions of human albumin and pure
calf thymus double strand deoxyribonucleic acid (ctdsDNA)
irradiated with Q-switched Nd:YAG laser at different rates (1, 3 Hz)
and time exposure (up to 60 seconds) using 532 nm (400 mJ) and
1064 (1200 mJ) nm wavelength with fixed spot size of 4 mm. The
effect of laser irradiation on the albumin solution also studied in the
presence of elemental salts of copper, zinc and iron.
Q-switched laser irrad
Five representative sampling stations were selected in upper region of Euphrates river. Bimonthly sampling were collected from December 2000 to December 2001. Rotifera showed high density in December 2000 while high density of cladocera which recorded in October .The results of relative abundance index showed that rotifera: Polyarthera dolichoptera , Keratella cochlearis , K. valga, Cephalodella auriculata and cladocera: Bosmina longirostris , B.coregoni ,Chydorus spharicus, were more abundant in study stations. The results of constancy index showed 4 taxa belonged to rotifera and 2 taxa belonged to cladocera which were considered constant in the Euphrates river, where the other species varied between accessory and accidental speci
... Show MoreIn this work optical window for infrared region was prepared by using Aluminum Oxide (Al2O3)material as antireflection coating on ZnSe substrate which covers the atmospheric window 3-5µm. the maximum transition was 97% at a wavelength 0f 4.4µm.
Many therapeutic methods used to encourage reparative processes of cartilage and accelerate their healing such as drugs, magneto-laser and so on. Twenty four adult New Zealand rabbits used in this study. They were divided in to two groups; control and treaded with He –Ne laser. A square skin flap done on the medial aspect of both auricles followed by pealing a square piece of cartilage from the auricle then the flaps sutured .The site of the operation in the rabbits of the treated group were irradiated with He –Ne laser 5mw power for seven days began after the operation directly. 3 rabbits from each group used for collection of specimens for histopathological examination at the 1, 2, 4 & 6 weeks post the operation. Significant
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