The effect of using different R -molar ratio under variable reaction conditions (acidic as well as basic environment and reaction temperature) have been studied. The overall experiments are driven with open and closed systems. The study shows that there is an optimum value for a minimum gelling time at R equal 2. The gelling time for all studied open system found to be shorter than in closed system. In acidic environment and when R value increased from 2 to 10, the gelling time of closed systems has increased four times than open systems at T=30 ?C and fourteen times when temperature reaction increased to 60 ?C. While in basic environment the influence of increasing R value was limited.
Improving the performance of visual computing systems is achieved by removing unwanted reflections from a picture captured in front of a glass. Reflection and transmission layers are superimposed in a linear form at the reflected photographs. Decomposing an image into these layers is often a difficult task. Plentiful classical separation methods are available in the literature which either works on a single image or requires multiple images. The major step in reflection removal is the detection of reflection and background edges. Separation of the background and reflection layers is depended on edge categorization results. In this paper a wavelet transform is used as a prior estimation of background edges to sepa
... Show MoreBackground: Complete seal of the root canal system following its chemo-mechanical debridement plays a pivotal role for achieving successful endodontic treatment. This can be established by reducing the gaps between the core filling material and root canal wall. Aim: To assess and compare the dislocation resistance of root canals obturated with GuttaFusion® and TotalFill BC sealer versus single cone obturation technique and TotalFill BC sealer after instrumentation of the canals with WaveOne, ProTaper Next and ProTaper Universal system. Material and Method: Sixty extracted human permanent mandibular premolars were conducted in the current study. The teeth were decorated and left the root with 15mm length; the roots were divided randomly i
... Show MoreCr2O3 thin films have been prepared by spray pyrolysis on a glass substrate. Absorbance and transmittance spectra were recorded in the wavelength range (300-900) nm before and after annealing. The effects of annealing temperature on absorption coefficient, refractive index, extinction coefficient, real and imaginary parts of dielectric constant and optical conductivity were expected. It was found that all these parameters increase as the annealing temperature increased to 550°C.
The ZnTe alloy was prepared as deposited thin films on the glass substrates at a thickness of 400±20 nm using vacuum evaporation technique at pressure (1 × 10-5) mbar and room temperature. Then the thin films under vacuum (2 × 10-3 mbar) were annealing at (RT,100 and 300) °C for one hour. The structural properties were studied by using X-ray diffraction and AFM, the results show that the thin films had approached the single crystalline in the direction (111) as preferred orientation of the structure zinc-blende for cubic type, with small peaks of tellurium (Te) element for all prepared thin films. The calculated crystallite size (Cs) decreased with the increase in the anne
... Show MoreThe isotretinoin drug is 13-cis-retinoic acid, is the treatment of severe acne and some skin cancers and used for dermatological conditions, this study was designed to detect the toxic role of the isotretinoin on the intrauterine development after implantation in albino mice during pregnancy. There are very little studies which indicating the side-effect of this drug on intra-uterine growth, so in the present research we tried to study the toxic effect of isotretinoin on the endometrial changes of uterus during the 2nd. and 3rd. trimester of gestation in pregnant mice after treatment with single chronic dose of the Isotretinoin drug (20 mg/B.wt) from first day of gestation until 21 days the last day of gestation.
The present study exa
This paper is dealing with an experimental study to show the influence of the geometric characteristics of the vortex generators VG son the thickness of the boundary layer (∂) and drag coefficients (CD) of the flat plate. Vortex generators work effectively on medium and high angles of attack, since they are "hidden" under the boundary layer and practically ineffective at low angles.
The height of VGs relative to the thickness of the boundary layer enables us to study the efficacy of VGs in delaying boundary layer separation. The distance between two VGs also has an effect on the boundary layer if we take into
... Show MoreThis work describes the inhibition effect of different concentration of an aqueous extract of Peganum harmala seed on the corrosion of carbon steel in 3.5 % sodium chloride solution using potentiostatic polarization techniques at the temperature range of 25°C to 55°C. The result show that inhibition efficiency increased with increasing concentration of the inhibitor extracts and temperature. The adsorption of inhibitor on carbon steel surface was fit into Langmuir adsorption isotherm. Kinetic and thermodynamic parameters governing the corrosion and adsorption process were calculated and discussed.
ABSTRACTBackground : Acne vulgaris is a
common skin disease, affecting more than 85% of
adolescents and often continuing into adulthood.
People between 11 and 30 years of age and up to
5% of older adults. For most patients acne remains
a nuisance with occasional flares of unsightly
comedones, pustules and nodules. For other less
fortunate persons, the sever inflammatory response
to Propionibacterium acnes (P.acnes) results in
permanent
Methods: Disfiguring scars. (1, 2) Stigmata of sever
acne cane lead to social ostracism, withdrawal
from society and severe psychologic
depression (1-4).
Result Pathogenesis of acne Traditionally, acne
has been thought of as a multifactorial disease of
the fo