Background: Polymers are very rarely used in their form. These modifications are carried out in order to improve the properties of polymers.Recently silver have been used successfully as antimicrobial (medical and dental) biomaterials that can prevent caries and infection of implants Purposes: The aim of the present in vitro study is to evaluate the effect of addition of silver nitrate to acrylic resin in different concentrationsthrough several tests part of these are: The effect of this additive on impact strength, transverse strength, and tensile strength of AgNO3 – loaded resin, and to assess any effect of addition of silver nitrate on coloration of acrylic resin. Materials and methods: Different concentrations of silver nitrate (9.375, 15, 30, 60, 120, 150, 300, 600 and 900 ppm) were prepared from stock solution of 1000 ppm silver nitrate. The specimens were prepared in accordance with the manufacturer's instructions and the tested silver nitrate solution was added to the acrylic resin powder and monomer in a fixed volume (0.2ml). Controls devoid of silver nitrate were included. Results: Fourier transform infra-red confirmed that there was no chemical bond between the Poly methyl methacrylate and silver nitrate. There was insignificant increasing (P=0.05) in impact strength observed when compared with control group. In transverse strength test, significant reduction was show (P<0.001). While for tensile strength there was insignificant reduction with 9.375(P=0.05NS) and 15(P=0.42NS) ppm silver nitrate. However, it was significant above 15 ppm (P<0.001). Darkening of silver nitrate -loaded resins were shown to be started with concentration of silver nitrateof 300 ppm and above. Conclusions: The additions of silver nitrate to acrylic resins yield good color stability and mechanical properties, depending on the concentration of silver nitrate.
Heavy metals especially lead (Pb), cadmium (Cd), chromium (Cr) and copper (Cu) are noxious pollutants with immense health hazards on living organisms, these pollutants enter aquatic environment in Iraq mainly Tigris and Euphrates rivers via waste water came from different anthropological activities, This study investigated capacity of dried and ground root of water hyacinth (Eichhornia crassipes) in removing the heavy metals from their aqueous solutions. Effects of initial concentrations of the heavy metals and pH of their aqueous solutions were studied. Results of this study revealed excellent biosorption capacity of water hyacinth root in general, removal of Pb was the highest and Cr was lowest. The results showed that the Pb, Cu and C
... Show MoreA kindergarten teacher is one of the most important elements in the educational process, since she is totally relied upon in kindergartens. Therefore, she could have basic and healthy characteristics to improve the educational process by directing the child towards a perfect growing upEducating and raising up a child should be an organized process that makes desirable changes in the child’s behavior in order to improve different sides of his personality, such as his appearance side, his mental side, and his social side.
This research aims at:
1- Measuring the scientific brilliance in kindergarten teachers.
2- Investigating the statistical significant differences of the scientific brilliance among kindergarten teachers in accor
This paper presents a grey model GM(1,1) of the first rank and a variable one and is the basis of the grey system theory , This research dealt properties of grey model and a set of methods to estimate parameters of the grey model GM(1,1) is the least square Method (LS) , weighted least square method (WLS), total least square method (TLS) and gradient descent method (DS). These methods were compared based on two types of standards: Mean square error (MSE), mean absolute percentage error (MAPE), and after comparison using simulation the best method was applied to real data represented by the rate of consumption of the two types of oils a Heavy fuel (HFO) and diesel fuel (D.O) and has been applied several tests to
... Show MoreMany condensed polymers [A1-A7] were prepared via reaction of (Ethylenediaminetetraacetic acid = EDTA), with different prepared imide-diamines by modification [ modification of amino acids and antibiotics (B1- B7)] Imide-diamines were prepared by chlorination of L-amino acids such as [ L-Histidine, L-Alanine, L-Valine, L-Glycine and L-Aspargine ] or selected antibiotics such as [Cephallixine monohydrate and Amoxilline ] with thionyl chloride at 0°C, then reacted with ammonia to obtain imidediamines [B1-B7] . The physical properties of all prepared condensed polymers [A1-A7], new prepared diamines [B1-B7] were studied and characterized by FT -IR spectroscope to certify the structural formulas. The thermal analysis (TGA, DTA) were studied, a
... Show More(E)-2-(benzo[d]thiazol-2-yliazenyl)-4-methoxyaniline was synthesized by reaction the diazonium salt of 2-aminobenzothiazole with 4-methoxyaniline. Identified of the ligand by spectral techniques (UV-Vis, FTIR,1HNMR and LC-Mass) and microelemental analysis (C.H.N.S.O) are used to produce of the azo ligand. Complexes of (Co2+, Ni2+, Cu2+ and Zn2+) were synthesized and identified using atomic absorption of flame, elemental analysis, infrared and UV-Vis spectral process as well conductivity and magnetic quantifications. Nature of compounds produced have been studied followed the mole ratio and continuous contrast methods, Beer's law followed during a concentration scope (1×10-4-3×10-4 mole/L). height molar absorptivity of compound solutions h
... Show MoreThis work aimed to investigate the prevalence of pathogenic fungi and evaluate the antifungal activity of Trichoderma orientale FMR12486 crude extract against pathogenic fungi isolated from patients attending the National Center for Thoracic and Respiratory Diseases (having a history of tuberculosis) and consultant of Dermatology of Baghdad hospital, Iraq. A total of 80 clinical specimens were collected: 20 skin scrapings specimens and 60 sputum specimens. The results of direct examination by KOH 10% and culture showed that 11 (55%) cases from 20 skin specimens were positive for fungal infections, while in the sputum specimens, 28 (47%) cases from 60 were positive. Candida albicans represented the most common fungal infection isolat
... Show MoreHeterogeneous organic compounds play an important role in our daily life as they contribute in many medical and industrial fields and are in continuous development as a result of the preparation of new derivatives with different properties. From this premise, the goal of this work appears, which is preparation of (four, five, six, and seven) membered ring systems derived from furfural, by its reaction with different aromatic aldehydes, and record their antioxidant activity by using free radical scavenging method of DPPH radicals. The new ring systems are synthesized by reacting the prepared Schiff-bases with different ring closure agents (chloroacetyl chloride, mercaptoaceticacid, anthranilic acid, and phthalic anhydride), the prep
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