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.
New Schiff base ligand 2-((4-amino-5-(3, 4, 5-trimethoxybenzyl) pyrimidin- 2-ylimino) (phenyl)methyl)benzoic acid] = [HL] was synthesized using microwave irradiation trimethoprim and 2-benzoyl benzoic acid. Mixed ligand complexes of Mn((ІІ), Co(ІІ), Ni(ІІ), Cu(ІІ), Zn(ІІ) and Cd(ІІ) are reacted in ethanol with Schiff base ligand [HL] and 8-hydroxyquinoline [HQ] then reacted with metal salts in ethanol as a solvent in (1:1:1) ratio. The ligand [HL] is characterized by FTIR, UV-Vis, melting point, elemental microanalysis (C.H.N), 1H-NMR, 13C-NMR, and mass spectra. The mixed ligand complexes are characterized by infrared spectra, electronic spectra, (C.H.N), melting point, atomic absorption, molar conductance and magnetic moment me
... Show MoreIn this work, varying compositions of SiO2 micro filler were added
with the Polyvinyl Chloride (PVC) and samples have been prepared
using film casting technique. The results have been analyzed and
compared for PVC samples with (1 wt%, 3 wt%, 5 wt% and 10 wt%)
SiO2 micro filler. Mechanical characteristics such as tensile strength,
elongation at break and Young`s modulus were measured for all the
samples, where the tensile strength was increased from 8.39 Mpa for
purified PVC to 16 Mpa for 3% SiO2/PVC composite. Also, thermal
conductivity measurement values illustrated that composite materials
have a good thermal insulation at 10 wt. %, thermal conductivity was
decreased from 0.1684 W/m.
The tetradentate N2O2 Schiff base ligand, which is produced via the condensation reaction of 2-hydroxynaphthaldehyde with phthalohydrazide, is prepared in this work with a fair yield. The prepared ligand was characterized using a microanalysis technique (C.H.N), UV-vis, FTIR, 1H-,13C-NMR, mass spectrometry, and thermal gravimetric analysis (TGA). New complexes were synthesized by a reaction between ligand (N'1E,N'2Z)-N'1,N'2-bis((1-hydroxynaphthalen-2yl)methylene)phthalohydrazide and metal chloride of Co+2, Ni+2, and Zn+2 ions in absolute ethanol. The present complexes are also characterized by techniques such as C.H.N, UV-vis, FTIR, TGA, molar conductivity, atomic absorption, and magnetic moment measurements. The in vitro antimicro
... Show MoreEstablishing sustainable cities and residential neighborhoods requires the development of new planning strategies, as adopting sustainable planning strategies when planning urban land uses for residential neighborhoods is necessary due to the large number of urban land use problems that have emerged during urbanization. The most prominent modern concept concerned with the land was the concept of sustainability, as sustainable planning aspires to link knowledge with sustainability through measures to achieve it. Therefore, sustainable planning works to apply the principles of sustainability in planning.
And in view of the circumstances that our country went through, which negatively affected various sectors and aspects of life, in
... Show MoreCompetitive advantage is a substantial strategic objective for organizations. It requires high levels in the quality of products and services provided to customers, continuous improvement of costing , care for creativity and innovative employees, and speed unique to the marketing and financial engineering, and business re-engineering processes. The situation in this area, requires actors to attract and develop human resources, including help in proper implementation of the strategic tasks that targeted by those institutions. According to the opinions and viewpoints of management scholars, the competitive advantage resource is the most important issue for organizations in the third millennium, which can be a
... Show MoreAt present, numerous novel chemical compounds face challenges related to their limited solubility in aqueous environments. These compounds are classified under the Biopharmaceutical Classification System (BCS) as either class II or class IV substances. Different carriers were used to increase their solubility. Candesartan cilexetil (CC) is one of the most widely used antihypertensive drugs, which belongs to class II drugs. The aim of this research was to enhance the solubility and dissolution rate of CC through a complexation approach involving β-cyclodextrin and its derivatives, specifically hydroxypropyl beta cyclodextrin (HP-β-CD), methyl beta cyclodextrin (M-β-CD), and sulfonyl ether beta-cyclodextrin (SBE-β-CD), serving as
... Show MoreABSTRACT: In this research SnO2 thin films have been prepared by using hot plate atmospheric pressure chemical vapor deposition (HPCVD) on glass and Si (n-type) substrates at various temperatures. Optical properties have been measured by UV-VIS spectrophotometer, maximum transmittance about (94%) at 400 0C. Structure properties have been studied by using X-ray diffraction (XRD) , its shows that all films have a crystalline structure in nature and by increasing growth temperature from(350-500) 0C diffraction peaks becomes sharper and grain size has been change. Atomic force microscopy (AFM) uses to analyze the morphology of the Tine Oxides surface structure. Roughness & Root mean square for different temperature have been investigated. The r
... Show MoreThis article aim to estimate the Return Stock Rate of the private banking sector, with two banks, by adopting a Partial Linear Model based on the Arbitrage Pricing Model (APT) theory, using Wavelet and Kernel Smoothers. The results have proved that the wavelet method is the best. Also, the results of the market portfolio impact and inflation rate have proved an adversely effectiveness on the rate of return, and direct impact of the money supply.