Background: The PMMA polymer denture base materials are low mechanical properties, adaptation of the denture base to underlying tissue is important for retention and stability of denture. The aim of the study was toevaluate the effect of mixtureZrO2-Al2O3 nanoparticles on impact strength, transverse strength, hardness, roughness, denture base adaptation of heat cured acrylic resin denture base material. Materials and methods: One hundred (100) specimens were prepared, the specimens were divided into five groups (20 specimens to each) according to the test type, each group was subdivided in to two subgroups (control and experimental) each subgroup consist of 10 specimens, the experimental group included mixture of 2% (ZrO2-Al2O3ratio2:1) by weight. Theimpact strength was measured by Charpy's impact testing machine, the transverse strength was measured by Instron testing machine while the hardness was measured byshore D durometer and roughness was measured by Profilometer. Denture base adaptation was measured by digital microscope and evaluated by computerized tomography (CT). Results: Highly significant increaseofimpact and transverse strength, non-significant increase ofhardness, significant increase ofroughness andreduction of denture base adaptation (measured at 3 point A, B and C) occurred in experimental groupwhen compared to control group. CT evaluation, gap between the denture base and master cast (control and experimental groups) increased from the anterior to posterior side of palate and from the alveolar ridge to the mid palatal line. Conclusion: The polymer nanocomposites had mechanical properties higher than neat PMMA at same time less denture base adaptation.
This research includes theoretical and evaluation design of a polarizer filter of high transmission in the near IR region of (900-1200nm) for different incidence angles to obtain a long wave and short wave pass filter using analytical calculations. Results refer to a new configuration design in fewer layers than used in previous studies in the long wave pass at incidence angles (45o,50o,55o). Adopted Hafnium dioxide (HfO2) and Magnesium fluoride (MgF2) as coating material at design wavelength (933nm), the study also included design short wave pass polarizer by using the same coating material.
The polyaniline powder was chemically manufactured by direct oxidation of aniline. The resulting polymer was characterized by the results of optical, measurements by (FT-IR) spectroscopy, we have detected some of the absorption peaks located at 3498, 2858 cm-1, which correspond N-H vibrations, and C-H expansion of the aromatic ring respectively as well as stretching vibrations of quinoid ring have been observed. Structural properties, such as the surface topography using an atomic force microscope (AFM), and Surface composition by (SEM) have been studied. The structure of some pellets of polyaniline powder have been examined by using analytical X-ray diffraction technique, the pattern of obse
... Show MoreThis work comprises the synthesis of new thioxanthone derivatives containing C-substituted thioxanthone. To obtain these derivatives, the o-mercapto benzoic acid was chosen as the starting material, which was reacted with dry benzene in sulfuric acid (98 %) to produce the thioxanthone (1). The 2,7-(disulfonyl phosphine imine) thioxanthone (4-8) were prepared from reaction of compound (1) with chlorosulfonic acid gave 2,7-(disulfonyl chloride) thioxanthone (2). Treatment of (2) with sodium azide to produce 2,7-(disulfonyl azide) thioxanthone (3). Condensation of (3) with phosphorus compounds afforded compounds (4-8). The 2,7-(disulfonamide) thioxanthone (9-21) was obtained when co
... Show MoreIn this work, we have examined the spectral response of (p-CuAlSe2/n-Si) detector, (CAS) thin films deposited by thermal evaporation at RT with a thickness (450) nm, and annealing temperature at (473K) for 2 h. Optical transmission measurements displayed reasonably slight transmission besides higher absorbance trendy the visible region, energy gaps were observed by annealing, were found to be direct, and decreased with the effect of annealing. The extreme responsivity value arises at wavelength 459 nm, with improvement value of specific detectivity and quantum efficiency the annealing films be situated originate as greatest suitable aimed at numerous device application.
In the present paper we report the synthesis of a new ligand [HL][(2-1-[(2-hydroxy-benzylidene)-hydrazono]-ethyl) benzene-1, 3, 5-triol and its complexes with (Mn", Fe", Cd", and Hg") The ligand was prepared in two steps. In the first step a solution of salicylaldehyed in methanol reacted under reflux with hydrazinemonohydrate to give an intermediate compound which reacted in the second step with 2, 4, 6-trihydroxidernonohydrate giving the tientioned ligand. The complexes were synthesis by direct reaction of the corresponding metal chloride with ligand. The ligand and the complexes have been characterized by spectroscopic methods [" H NMR, IR, UV-Vis,, atomic absorption], HPLC microanalysis along with conductivity measurements. From the abo
... Show MoreThe current study included the collection of 175 samples of blood (Urea-blood) of patients with rheumatoid arthritis from Al–Al-Kindy Teaching Hospital, Baghdad Teaching Hospital and Al-Imamian Al-Kadhimyain Medical City in Baghdad from both sexes with different ages at the period between 1/10/2016-1/2/2017. Bacterial growth results showed that 80% of urea for bacterial transplantation were positive results, while the number of samples showing no bacterial growth was 20%. The bacterial isolation evaluate for morphological testes and biochemical microscopy, as well as identification by Api system. The highest frequency of inflectional bacteria was E. coli (41.97%), followed by E. cloacae (21.25%), P. aeruginosa (12.5%), Salmonella (10%), K
... Show MoreVariable-Length Subnet Masks (VLSM), often referred to as "subnetting a subnet", is used to maximize addressing efficiency. The network administrator is able to use a long mask on networks with few hosts, and a short mask on subnets with many hosts. This addressing scheme allows growth and does not involve wasting addresses. VLSM gives a way of subnetting a network with minimal loses of IP addresses for a specific range. Unfortunately, the network administrator has to perform several mathematical steps (or use charts) to get the required results from VLSM. In this paper, a simple graph simulator is proposed (using Visual Basic 6.0 Language) to perform all the required mathematical steps and to display the obtained required information (the
... Show MoreThe purpose of this paper is to prove the following result: Let R be a 2-torsion free ring and T: R?R an additive mapping such that T is left (right) Jordan ?-centralizers on R. Then T is a left (right) ?-centralizer of R, if one of the following conditions hold (i) R is a semiprime ring has a commutator which is not a zero divisor . (ii) R is a non commutative prime ring . (iii) R is a commutative semiprime ring, where ? be surjective endomorphism of R . It is also proved that if T(x?y)=T(x)??(y)=?(x)?T(y) for all x, y ? R and ?-centralizers of R coincide under same condition and ?(Z(R)) = Z(R) .