In this study, poly4-(nicotinamido)-4-oxo-2-butenoic acid (PNOE) was prepared by the electro polymerization of 4-(nicotinamido)-4-oxo-2-butenoic acid (NOE) monomer on a 316 stainless steel (St.St) which acts as an anticorrosion coating. Fourier transforms infrared (FTIR), atomic force microscopy (AFM), scanning electron microscopy (SEM), and cyclic voltammetry were used to diagnose the structure and the properties of the prepared polymer layer. The corrosion behavior of the uncoated and coated 316 St.St were evaluated by using an electro chemical polarization technique in 0.2 M hydrochloric acid solution as a corrosive medium at a temperature range of 293 to 323 K. Nano materials, such as nano ZnO and graphene were added in different concentrations to the monomer solution for improving the corrosion resistance of the 316 St.St surface. The results showed that the values of protection efficiencies of the polymeric coating were increased after adding the nano materials. The kinetic and thermodynamic activation parameters were also calculated and the biological activity of the polymer film against Gram negative and positive bacteria was studied.
Braces in straight bridge systems improve the lateral-torsional buckling resistance of the girders by reducing the unbraced length, while in horizontally curved and skew bridges, the braces are primary structural elements for controlling deformations by engaging adjacent girders to act as a system to resist the potentially large forces and torques caused by the curved or skewed geometry of the bridge. The cross-frames are usually designed as torsional braces, which increase the overall strength and stiffness of the individual girders by creating a girder system that translates and rotates as a unit along the bracing lines. However, when they transmit the truck’s live load forces, they can produce fatigue cracks at their connection
... Show MoreThis work study the effect of laser surface heat treatment on physical properties (green density, density after sintering, theoretical density and porosity)of a composite material of an Al powder as a matrix with different percentage of B4C powder as additive material. This work was done by two stages: First stage: Production the maincomposite material which is contain Al powder with grain size 24μm as a matrix and B4C powder with grain size 50μm as additive with different weight percentage (5%,10%,15%,20%,25%,30%), and the powders Maxined for suitable time 15min, after that the mixture compacted with 2ton and sintered at 550C0. Second stage: Laser surface treatment was done for the productive composite material after sintering by usin
... Show MoreBackground: The aim of the study was to investigate the effect of surface treatments of zirconia (grinding and sandblast with 50μm, 100 μm) on shear bond strength between zirconia core and veneering ceramic. Material and methods: Twenty-eight presintered Y-TZP ceramic specimens (IPS e.max ZirCAD, Ivoclar vivadent) were fabricated and sintered according to manufacturer’s instructions. The core specimens were divided randomly in to 4 groups, group 1: no surface treatment, group2: zirconia specimens were ground with silicon carbide paper up to1200 grit under water cooling, group3: zirconia specimens were ground and sandblast with 100 μm alumina, group 4: zirconia specimens were ground and sandblast with 50 μm alumina. Surfa
... Show MoreIn this research, a sensor for chemical solutions was designed and formed using optical fiber-based on a surface Plasmon resonance technology. A single-mode optical fiber with three different diameters (25, 45 and 65) µm was used, respectively. The second layer of the low refractive fiber was replaced by gold, which was electrically deposited at 40 µm thickness. For each of the three types of optical fiber, different saline concentrations (different index of refraction) were used to evaluate the performance of the refractive index sensor (chemical sensor) by measuring its sensitivity and resolutions. The highest values we could get for these two parameters were 240mm/RIU, and 6*10-5 RIU respectively, when the diameter of a
... Show MoreBackground: Adjustment of any premature occlusal contact of any zirconia restoration requires its polishing or glazing in order to restore the smoothness of the restoration. The objective of this in vitro study was to evaluate the effects of different polishing systems and glazing on the surface roughness of full-contour zirconia. Material and methods: Forty disks (diameter: 8 mm, thickness: 6.4 mm) were prepared from pre-sintered full-contoured zirconia block; they were colored and sintered in a high-temperature furnace at 1500ËšC for 8 hours. The specimens were then leveled and finished using grinding and polishing machine and adjusted using diamond disk. The specimens were then randomly divided into four groups (n=10), group I involves
... 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 MoreOrphenadrine is an anticholinergic ,antimuscarinic , centrally acting skeletal muscle relaxant .It presents in the form of citrate and HCl salts which are used in treatment of the symptoms of mild Parkinson's disease and also it is used as adjuvant with other drugs in the therapy .
Many trials were made to formulate Orphenadrine citrate as a plain tablet using wet granulation or direct compression technique in order to get a satisfactory formula through studying the effect of various factors such as binders , diluents and disintegrants types .
The best formula was obtained by using Poly Vinyl Pyrolidine (PVP) as a binder also the results indicated that starch and mannitol
... Show MoreNystatin is the drug of choice for treatment of cutaneous fungal infections with main disadvantage that is the need for multiple applications to achieve complete eradication which may reduce patient compliance. Microparticles offer a solution for such issue as they are one of sustained release preparations that achieve slow release of drug over an extended period of time. The objectives of this study were to fabricate nystatin-loaded chitosan microparticles with the ultimate goal of prolonging drug release and to analyze the influence of polymer concentration on various properties of microparticles. Microparticles were prepared by chemical cross-linking method using glutaraldehyde as cross-linking agent. Five formulas, namely N1C1, N1C2,
... Show MoreIn this article, we investigate the peristaltic flow of a Powell-Eyring fluid flowing in an asymmetrical channel with an inclining magnetic field through a porous medium, and we focus on the impact that varying rotation has on this flow. Long wavelength and low Reynolds number are assumed, where the perturbation approach is used to solve the nonlinear governing equations in the Cartesian coordinate system to produce series solutions. Distributions of velocity and pressure gradients are expressed mathematically. The effect of these parameters is discussed and illustrated graphically through the set of figures. To get these numerical results, we used the math program MATHEMATICA.