In this paper the behaviour of steel frames is investigated under an applicable range of initial ROTATIONAL geometric IMPERFECTION in joints, which are mostly created during the manufacturing process. A nonlinear analysis is applied in both geometry and material behaviour of steel frames. The results show considerable reduction in buckling and ultimate load carrying capacity of portal frames, when they are affected by a ROTATIONAL IMPERFECTION.

Background: Arterial occlusions are divided as acute and chronic. Emboli is the most common cause of acute arterial occlusion, which is treated by perforating embolectomy using fogarty catheter. Some of these cases that are not diagnosed in early phase of the disease (within the first month), should be treated using open surgical techniques, since embolectomy via fogarty catheter is not effective in such instances. Case report: In this study we reported a 55 years old lady with subclavian-axillary artery occlusion who was suffered from critical limb ischemia. For the first time in Iran we used Rotator-Aspirer appreture for thrombectomy in this patient.Conclusion: Following the intervention, distal pulses were pulpated and ischemic signs and symptoms faded completely.

Buckling analysis of rectangular functionally graded plates with geometrical IMPERFECTIONs is studied in this paper the equilibrium, stability, and compatibility equations of an imperfect functionally graded plate are derived using the first order shear deformation theory. It is assumed that the non-homogeneous mechanical properties of the plate, graded through the thickness, are described by a power function of the thickness variable. The plate is assumed to be under in-plane compressive load. Resulting equations are employed to obtain the closed-form solutions for the critical buckling load of an imperfect functionally graded plate. The influence of transverse shear on buckling behavior of the plate is discussed. The results are validated with the known data in the literature.

In this study, the effect of material IMPERFECTION on the free vibration response of perfect and imperfect FG plate is studied. A new hyperbolic shear deformation function is presented in this paper. The new hyperbolic function is chosen in such a way that the degree of the function is reduced as much as possible, despite the sufficient accuracy, so that the calculation speed is greatly reduced. The properties of the FG plate varied along the thickness according to power law. The material composition in production process cannot be completely in accordance with the expected pattern, which leads to the production of imperfect FG material. The governing differential equations are derived using the Hamilton’s principle. The obtained equations were solved using the Navier method with simple boundary conditions. The effects of important geometric and mechanical parameters of perfect model and two types of imperfect model, including length to thickness ratio, length to width ratio, wave number and power-law exponent on natural frequency response of imperfect FG plate are investigated. To verification, the analytical results obtained in this study are compared with the results presented in the literature, and in this comparison, a good agreement was obtained, which shows the correctness theory, deriving and solving equations.

The objective of this study was the comparison of Bare Sclera and ROTATIONAL Flap methods in primary pterygium surgery.This study was retrospective Cohort and studied population were 80 patients (40 patients in each group) with primary pterygium in stage II and III operated in Hamadan Emam Khomeini hospital , during 2001-2003. All of the patients followed up 48 hours, 1 week , 1,3 and 6 months after operative surgery.In this study , complications and recurrences of both methods (Bare Sclera and ROTATIONAL Flap) were compared and the results were as follows: Recurrence rate in Bare Sclera method was 22.5% and in ROTATIONAL flap method 11.1% , that obtained no significant relationship between two groups. Also there was not significant difference in complications.

This article presents the study of wave mechanics in a multiferroic structure having IMPERFECTION in the structure’s interface. This article reflects the study of shear horizontal (SH) wave propagation in a layered cylindrical structure consisting of thin layers of different materials (reinforced material and piezomagnetic material) with an imperfect interface. The interface considered between both materials is mechanically imperfect. Dispersion relations are achieved analytically. Distinct graphs are drawn (numerically) to exhibit the influence of parameters like rotation, initial stress, and mechanically imperfect parameters on phase velocity. Numerical results are drawn analytically and explained for each affecting distinct parameters for materials and interface. Parametric results on the phase velocities yield a significant conclusion of which some are: (a) Performance of Piezo with reinforcement material have an influential impact on wave velocity. (b) The mechanical IMPERFECTION affects the significantly on wave velocity (c) The Reinforcement/PM stiffening can monotonically up the velocity of phase velocity.

Thin wall shell structure has low weight and high resistance. The load capacity, buckling behavior and post buckling behavior of steel tanks thin wall, is very sensitive to geometric IMPERFECTIONs. Due to the small wall thickness of the shell structures enabling the creation of any deformation and there is a disturbance on the surface of the wall. Considering the types of errors occurred when build or assembled these structures, are not built these structure, ideally.This IMPERFECTIONs may be in the process of rolling, removable panels, installation or welding arise. Incomplete reports about the negative impact of the effect of welding on the axial bearing capacity.Comprehensive research on the effects of IMPERFECTION of initial geometrical shape on the steel tank vibration modes, and its effect on the bearing capacity steel storage tanks that considerable research It's not done. In this research, the actual behavior of cylindrical shells with initial geometric IMPERFECTIONs on mode shapes steel tanks in the pre-buckling and post-buckling. And the effect of initial geometric IMPERFECTIONs on steel tanks slashing been paid. Using finite element software, ABAQUS, and verification of the results of the analysis and nonlinear analysis with experimental results. Been paid. Imperfect geometric shape has changed mods. The effect of these changes on slashing are very small.

Most ROTATIONAL variations in young children, such as in-toening, and torticollis, are benign and resolve spontaneously. Understanding the normal variations in otherwise healthy children is vital to identifying true structural abnormalities that require intervention. A deliberate assessment of the ROTATIONAL profile is necessary wben evaluating children who in-toe or out-toe. In-toeing is usually attributable to metatarsus adductus in the infant, internal tibial torsion in the toddler, and femoral anteversion in children younger than 10 years. Out-toeing patterns largely result from external rotation hip contracture, external tibial torsion, and external femoral torsion.

In the present paper, ROTATIONAL rheometers along with their different measuring geometries are reviewed. The governing equations for calculating material functions in using each geometry are discussed and the advantages, shortcomings, the sources of error and the way to avoid them are well explained. The coaxial cylenders are very sensitive at very low viscosities, whereas, making normal force measurements are not practical The parallel-plate geometry can be easily used but very gross approximations are needed in calculations of rheological material functions. In the case of cone-plate geometry there exists straightforward relation between measured quantities and rheological material functions. The only withdrawal of this geometry is their interactions with solid materials in composite materials. The ability of accentric geometry to produce oscillating mode of loading using simple rotation has attracted many attentions. Some examples of diverse applications of ROTATIONAL rheometers are also reported.

1. Introduction:Free forms are usually used to refer double curve surfaces which are independent from groups of geometrically or mechanically constrained forms. Geometrically constrained forms are only conditioned by a geometrical definition, like it could be done on basis of simple surfaces. When there is a close relationship between forms and forces, the forms are mechanically constrained [1]. In the present study, behavior of double domes free form single layer space structures as a group of free form structures are investigated. Gaussian curvature of double domes can be positive and negative, unlike regular domes. In single layer reticulated space structures, local instability with nodal snap-through phenomenon could result in propagation in whole structure [2], so stability behavior of double domes free form single layer space structures should be investigated. The parametric study is performed in order to evaluate the effects of different variables on the stability behavior of double domes free form space structures.