Background: The base of the denture is largely responsible for providing the prosthesis with retention, stability, and support by being closely adapted to the oral mucosa. However; the process of bone resorption is irreversible and may lead to an inadequate fit of the prosthesis; this can be overcome by relining. Materials and methods: Acrylic based soft denture liner is prepared by preparing polymer from purified methylmethacrylate monomer with (10-2) initiator and (30%) dibutylphthalate plasticizer concentrations. Biological properties were evaluated in comparison with the control material through subcutaneous specimens' implantation in the New Zealand rabbits. Excisional biopsies were taken after (1, 3, days 1, 2, 3, 4 weeks) period. Microscopically, sections are studied to explore the consequences of thecontact with tested material and tissue response. Tensile strength, percentage of elongation, compressive, bond, and peel strengthwere evaluated; as well as water sorption and solubility is compared with the control material. Results: Histological study of the sections contained experimental and control materials showed normal tissue response by normal infiltration of the inflammatory cells; acute in the first days then chronic inflammatory cells were seen in the subsequent periods. Finally capsular enclosure of the specimens was well characterized and seen after 4 weeks. Results of the mechanical properties showed non-significant differences for the tested properties except the percentage of elongation; control material recorded significantly higher value. Moreover, statistically; water sorption of the experimental material was significantly lower than the control material; while the tested materials showed non-significant differences regarding the solubility test. Conclusion: The recommended formula of preparing heat-cured; acrylic based denture soft liner showed acceptable properties. Further evaluations of the experimental material were suggested.
A comparative investigation of gas sensing properties of SnO2 doped with WO3 based on thin film and bulk forms was achieved. Thin films were deposited by thermal evaporation technique on glass substrates. Bulk sensors in the shape of pellets were prepared by pressing SnO2:WO3 powder. The polycrystalline nature of the obtained films with tetragonal structure was confirmed by X-ray diffraction. The calculated crystalline size was 52.43 nm. Thickness of the prepared films was found 134 nm. The optical characteristics of the thin films were studied by using UV-VIS Spectrophotometer in the wavelength range 200 nm to 1100 nm, the energy band gap, extinction coefficient and refractive index of the thin film were 2.5 eV , 0.024 and 2.51, respective
... Show MoreThe semiconductor ZnO is one of II – VI compound group, it is prepare as thin films by using chemical spray pyrolysis technique; the films are deposited onto glass substrate at 450 °C by using aqueous zinc chloride as a spray solution of molar concentration 0.1 M/L. Sample of the prepared film is irradiating by Gamma ray using CS 137, other sample is annealed at 550°C. The structure of the irradiated and annealed films are analyzed with X-ray diffraction, the results show that the films are polycrystalline in nature with preferred (002) orientation. The general morphology of ZnO films are imaged by using the Atomic Force Microscope (AFM), it constructed from nanostructure with dimensions in order of 77 nm.
The optical properties o
Theoretical and experimental investigations of free convection through a cubic cavity with sinusoidal heat flux at bottom wall, the top wall is exposed to an outside ambient while the other walls are adiabatic saturated in porous medium had been approved in the present work. The range of Rayleigh number was and Darcy number values were . The theoretical part involved a numerical solution while the experimental part included a set of tests carried out to study the free convection heat transfer in a porous media (glass beads) for sinusoidal heat flux boundary condition. The investigation enclosed values of Rayleigh number (5845.6, 8801, 9456, 15034, 19188 and 22148) and angles of inclinations (0, 15, 30, 45 and 60 degree). The numerical an
... Show MoreThe present study was performed to evaluate the level of some risk factors (biochemical and immunological) in hypothyroid Iraqi patients considering the different thyroid functional states (hypothyroidism and subclinical hypothyroidism).The study includes 82 patients clinically diagnosed with hypothyroidism. Three study groups have been investigated: (47 clinical hypothyroid patients, 12 subclinical hypothyroid patients 23 healthy individuals) of different ages. This study, show that the proportion of females (83.3 %), (87.2%) in subclinical and clinical hypothyroidisim respectively higher than the proportion of males (16.7%),(12.8%) in subclinical and clinical hypothyrodism respectively of the total patients.The majority of subclinical hyp
... Show MoreThe effect of laser radiation on human aorta, coronary, and pulmonary arteries, and pulmonary veins has been investigated. Xenon-Chloride (eximer), Nitrogen, and Nd-YAG pulsed lasers of wavelengths 308, 337, and 1060 nm respectively were used. Their effects on fresh postmortem tissues, normal and diseased, was studied. The diameter and depth of ablation of the exposed tissues, in air, were measured as a function of many factors related to the type of laser and nature of the tissue. The effect of properties of the applied lasers, such as average power density and deposited energy density, on the exposed tissue surface were studied. The increase of these two parameters cause an increase in the depth and diameter of ablation. However the di
... Show MoreA new ligand (H4L) and its complexes with (CoII, NiII, CuII and PdII). This ligand was prepared in two steps, in the first step a solution of terephthaldehyde in methanol reacted under refluxe with 1,2-phenylenediamine to give precursore compound which reacted in the second step with 2,4- dihydroxybenzaldehyde to give the ligand. The complexes were synthesized by direct reaction of the corresponding metal chloride with the ligand. The ligand and complexes were characterized by spectroscopic methods [FT-IR, UV-vis, 1HNMR, HPLC and atomic absorption], chloride contant in addition to conductivity measurement. The stability constant K and Gibbs free energy ∆G were calculated for [[Ni2(H2L)Cl2], [Cu2(H2L)Cl2] complexes using spectrophoto
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