Background: Denture fracture is one of the most common problems encountered by the patients and prosthodontists. The objective of present study was to evaluate the transverse strength of nylon denture base resin repaired by using conventional heat polymerized, autopolymerized and visible light cure {VLC} resins, surface treatment that used for repair and adjustment of insufficient nylon denture bases and in case of addition of artificial teeth. As these corrective procedures are common chair side procedures in dental clinic. Materials and methods: One hundred twenty nylon specimens were prepared by using metal patterns with dimension of (65x10x2.5 mm) length, width, and thickness respectively for transverse strength test while for tensile bond strength a dumbbell-shaped with measurement (65x12.5x25mm) length, width, and thickness respectively were flasked with stone. The nylon specimens were molded by reflasked with dental stone that used as an index for these specimens in the repair procedure and repaired with 45 degree bevel joint by using metal holding device. The two parts of nylon specimen to be repaired were realigned in its repair index and adhere with special adhesive material to stabilize the combination during repair procedure. The dough of heat and cold cure resin was packed into the joint and then cured. The specimen repaired with cold cure resin was placed in the Ivomat containing water at (40°C) and pressure (30IB/inch²) for 15 minutes. The specimen repaired with {VLC} was placed in the light cure unit for 4 minutes following manufacturer’s instruction. The fractured nylon specimens were divided according to the type of repaired materials into (40) specimens received heat cure acrylic and the (40) specimens received cold cure acrylic and the other 40 specimens received {VLCR}. Each 40 specimens were subdivided according to the type of surface treatment received into 20 specimens were treated with coarse stone bur (control), 20 specimens were treated with combination of coarse stone bur and monomer of the heat cure acrylic. After that the specimens were subjected to transverse {Tr} and tensile bond {TB} strength tests. For each test 10 specimens. Results and conclusions: This study showed that specimens treated with combination of coarse stone bur and monomer of the acrylic (heat, cold or VL cure) had the highest transverse and tensile strength values, followed by the specimens treated with coarse stone bur. The results showed that the specimens repaired with heat cure acrylic had transverse and tensile strength values higher than the specimens repaired with cold and VL cure acrylic when compared between subgroups of heat, cold and VL cure acrylic that received the same treatments.
In our research, we introduced new concepts, namely *and **-light mappings, after we knew *and **-totally disconnected mappings through the use of -open sets.
Many examples, facts, relationships and results have been given to support our work.
Image processing is an important source for the image
analytical in order to get variable parameters such as the
intensity .In present work it has been found a relation between the tensity and number of pixd in the image , and from this relation we have got in this paper the inten
... Show MoreThree-dimensional nonlinear thermal numerical simulations are conducted for the friction stir welding (FSW) of AA 7020-T53. Three welding cases with tool (rotational and travel) speeds of 900rpm-40mm/min, 1400rpm-16mm/min and 1400rpm-40mm/in are analyzed. The objective is to study the variation of transient temperature in a friction stir welded plate of 5mm workpiece thickness. Based on the experimental records of transient temperature at several specific locations during the friction stir welding process for the AA 7020-T53, thermal numerical simulation is developed. The numerical results show that the temperature field in the FSW process is symmetrically distributed with respect to the welding line, increasing travel speed decreasing tran
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ZnO organic hybrid junction (electroluminescence EL device) was fabricated using phase segregation method. ZnO-nanoparticle (NPs) was prepared as a colloidal by self–assembly method of Zinc acetate solution with KOH solution. Nanoparticle is employed to form organic-inorganic hybrid film and generate white light emission, while N,N’–diphenyl-N,N’ –bis(3-methylphenyl)-1,1’-biphenyl 4,4’-diamine (TPD) and polymethyl methacrylate (PMMA) are adopted as the organic matrices. ZnO NPs was used to fabricate TPD: PMMA: ZnO NPs hybrid junction device. The photoluminescence (PL) and electroluminescence (EL) spectra of the TPD: PMMA: ZnO NPs hybrid device provided a broad emission band covering entirely the visible spectrum (∼350-∼700
... Show MoreIn this paper, a microcontroller-based electronic circuit have been designed and implemented for dental curing system using 8-bit MCS-51 microcontroller. Also a new control card is designed while considering advantages of microcontroller systems the time of curing was controlled automatically by preset values which were input from a push-button switch. An ignition based on PWM technique was used to reduce the high starting current needed for the halogen lamp. This paper and through the test result will show a good performance of the proposed system.
Innovative various Schiff bases and their Co(II), Ni(II) and Cu(II) and Hg(II) compounds made by the condensation of 4-amino antipyrine with derived aminobenzoic acid (2-aminobenzoic acid, 3-aminobenzoic acid, and 4-aminobenzoic acid ) have been prepared by conventional approaches. These complexes were described by magnetic sensibility analysis, FT-IR spectra, and molar-conductance and elemental analysis. Analytical values appeared which the mixed-ligand complexes presented ratio about 2:1 (ligand: metal) with the chelation 4 or 6. The prepared compounds offered a good effect on the organisms; bacteria Staphylococcus-aurous, Escherichia-coli and fungi C. albicans, A. niger. Also, the biological products signalize which the mixed compl
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This study came to show the importance of long hope and its extent on human life, and I found that through the research, the majority of the scholars did not address this topic separately, and did not explain the travails of this situation and the worldly problems it causes to its owner, and the consequences that fall upon it in the hereafter. Most of the studies inside of the books consisted of a simple presentation of this problem and an explanation of the remedies that came to us from the Qur'an and the hadiths and the Sunnah, and on the sayings of the imams of guidance (may the best prayers and peace be upon them), and on the chosen companions and followers, may God be pleased with them, but the length of hope does not stop At a certain
... Show MoreThis study includes the direct influence of (single & multi) dose of Cold Atmospheric Plasma (CAP) on the no. of platelets for mice for different exposure time (15, 30, 60, and 120) sec. the influence of CAP on mice was measured after 1, 2, 3, 7, and 14 day from exposure.
The results obtained in this study indicate that the effect of low doses of CAP on platelets was stimulatory effect in the first few hours from exposure (1day) but the high dose was inhibitory, It was found that after two weeks of exposure that the number of platelets became normal comparable to the control one, and this indicates that plasma effect was removed after this period.