Background: Glass ionomers have good biocompatibility and the ability to adhere to both enamel and dentin. However, they have certain demerits, mainly low tensile and compressive strengths. Therefore, this study was done to assess consistency and compressive strength of glass ionomer reinforced by different amount of hydroxyapatite. Materials and Methods: In this study hydroxyapatite materials were added to glass ionomer cement at different ratios, 10%, 15%, 20%, 25% and 30% (by weight). The standard consistency test described in America dental association (ADA) specification No. 8 was used, so that all new base materials could be conveniently mixed and the results would be of comparable value and the compressive strength test described by
... Show MorePorous silicon (PS) layers are prepared by anodization for
different etching current densities. The samples are then
characterized the nanocrystalline porous silicon layer by X-Ray
Diffraction (XRD), Atomic Force Microscopy (AFM), Fourier
Transform Infrared (FTIR). PS layers were formed on n-type Si
wafer. Anodized electrically with a 20, 30, 40, 50 and 60 mA/cm2
current density for fixed 10 min etching times. XRD confirms the
formation of porous silicon, the crystal size is reduced toward
nanometric scale of the face centered cubic structure, and peak
becomes a broader with increasing the current density. The AFM
investigation shows the sponge like structure of PS at the lower
current density porous begi
Background: The isthmus is a difficult area in the root canal complex to manage. The research aimed to evaluate the efficiency of three different obturation techniques (lateral condensation, EandQ (thermoplasticized gutta percha system) and Soft Core (thermoplasticized core carrier gutta percha system)) to obturate the isthmus area of roots prepared by two different instrumentation techniques (rotary ProTaper universal and ProTaper Next systems). Material and method: Sixty freshly extracted teeth were randomly divided into two main groups (A and B) of 30 teeth each. Group A was prepared by rotary ProTaper Universal whereas group B was prepared by ProTaper Next system. Each main group was then randomly subdivided into three subgroups of 10 t
... Show MoreThe size and the concentration of the gold nanoparticles (GNPs)
synthesized in double distilled deionized water (DDDW) have been
found to be affected by the laser energy and the number of pulses.
The absorption spectra of the nanoparticles DDDW, and the
surface plasmon resonance (SPR) peaks were measured, and found to
be located between (509 and 524)nm using the UV- Vis
spectrophotometer. SPR calculations, images of transmission
electron microscope, and dynamic light scattering (DLS) method
were used to determine the size of GNPs, which found to be ranged
between (3.5 and 27) nm. The concentrations of GNPs in colloidal
solutions found to be ranged between (37 and 142) ppm, and
measured by atomic absorptio
The behaviour of certain dynamical nonlinear systems are described in term as chaos, i.e., systems' variables change with the time, displaying very sensitivity to initial conditions of chaotic dynamics. In this paper, we study archetype systems of ordinary differential equations in two-dimensional phase spaces of the Rössler model. A system displays continuous time chaos and is explained by three coupled nonlinear differential equations. We study its characteristics and determine the control parameters that lead to different behavior of the system output, periodic, quasi-periodic and chaos. The time series, attractor, Fast Fourier Transformation and bifurcation diagram for different values have been described.
Vehicle Air Conditioning (AC) systems are used in countries that suffer high temperature degrees during the summer season, one of these countries is Iraq. Most passengers suffer manifestations which may lead to Allergic or Respiratory diseases as they inhale polluted air produced by AC systems.
In this study 10 vehicle were selected randomly on the basis of noxious odors emitted from AC systems. Indoor air samples were collected by using impaction method and using Sabouraud's dextrose agar to grow and isolate dominant fungi species accompanied with AC polluted air. Dust particle diameters aggregated in AC filters were measured because the particles work as transporters to carry fungi then get inhaled by the passengers. After isolating
AN Salih, LO Hamza, Ann. For. Res, 2022 - Cited by 2
The anatomical study showed the epidermis leaves of Ricinus communis L.glabrous and withparacytic pattern, also the midrib of leavescomposedfrom a pyramidal shapearea with a circular tip like ascamel humpfrom the upper side consisting of supported collenchyma tissue, and the cross section of leaf petiole formed as an ovate shape as for the cross section of stem was a circular, also observed many druces crystaland aleuron grains that are spread in the cortex area. Pollen grain appeared under a scanning electron microscope that tricolporate, either the surface pattern was reticulate and the shape of pollen grain prolate spheroidal to subprolate
يمثل الأخذ بالنظام الفيدرالي أطاراً تنظيمياً لشكل الدولة و مرحلة تحول مهمة في بنية الدولة العامة في مختلف مجالاتها، فالانتقال من المركزية في أدارة الشؤون العامة للدولة الى النمط الفيدرالي يمثل تحولا بنيوياً وسيكولوجياً ،حيث يكون هنالك توزيع مكاني - عمودي للسلطة والثروة بين الوحدات المكونة للدولة بشكل يختلف كليا عن الحالة المركزية، ونجد صور تنظيمية عديدة تتأسس ضمن اطار الفيدرالية العام ،
... Show MoreIn this work ,porous silicon(PS) substrate has been used to fabricate a sensor of structures(Al/n PSi/n-Si/Al) using infrared laser in a assisting Etching process at several times (8,16,and24 min) and current density(J) of about(25mA/cm2) on silicon(Si) substrates type of n and tested for CO2 gas molecules and then modulated using MATLAB program. J-V characteristic was analyzed. Different parameter determine such as, Porosity (%), Layer thickness (%) and relative permittivity of the fabricated PS substrate. Several shape and sizes of pores were obtained from the scanning electron microscope device such as pore, rectangular and cylindrical structure for infrared illuminated (IR). The Porosity (%) and Layer thickness (%) take control on se
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