In this paper, recommended spiral passive micromixer was designed and simulated. spiral design has the potential to create and strengthen the centrifugal force and the secondary flow. A series of simulations were carried out to evaluate the effects of channel width, channel depth, the gap between loops, and flowrate on the micromixer performance. These features impact the contact area of the two fluids and ultimately lead to an increment in the quality of the mixture. In this study, for the flow rate of 25 μl/min and molecular diffusion coefficient of 1×10-10 m2/s, mixing efficiency of more than 90% is achieved after 30 (approximately one-third of the total channel length). Finally, the optimized design fabricated using proposed 3D printing method.

In this research, in order to investigate the effect of the piezoelectric patch which is used as a sensor or actuator in rotating flexible structures such as a helicopter blade, the free vibrations of the rotating rectangular sheet with and without the piezoelectric patch have been presented. First-order shear deformation theory is considered for plate displacement and piezoelectric field. Considering the effect of Coriolis acceleration, centrifugal acceleration and centrifugal in-plane forces, the equations of motion are derived from Hamilton's principle and the electromechanical couple equation is obtained from Maxwell's equation. For piezoelectric, two electrical conditions, open circuit and closed circuit, which are used in sensors and actuators, respectively, have been considered. The equations are discretized with the help of the Numerical method of generalized differential squares and the matrices of inertia mass, eccentricity, Coriolis and stiffness matrix are obtained. Natural frequency values for beam and rotating plate have been compared in Abaqus software. Also, the values obtained from the Numerical solution in MATLAB have been verified with articles and ABAQUS, which have high accuracy. The effect of parameters such as hub radius, rotation speed, sheet thickness, aspect ratio, piezoelectric patch thickness and applied voltage on the natural frequency of the system has also been investigated.

Plastic hinge properties play a crucial role in predicting the nonlinear response of structural elements. The plastic hinge region of reinforced concrete normal beams has been previously studied experimentally and analytically. The main objective of this research is to evaluate the behavior of the plastic hinge region of reinforced concrete deep beams and its comparison with normal beams through finite element simulation. To do so, ten beams contain six deep beams, and four normal beams, under concentrated and uniformly distributed loading, are investigated. Lengths in the plastic hinge region involving curvature localization, rebar yielding, and concrete crushing zones are studied. The results indicate that the curvature localization zone is not suitable for the prediction of plastic hinge length in reinforced concrete deep beams. Based on the results it can be stated that in simply supported normal beams the concrete crushing zone is focused on the middle span, but in simply supported deep beams by creating a compression strut between loading place and support, the concrete crushing zone spreads along the compression trajectory. The rebar yielding zone of simply supported beams increases as the loading type is changed from the concentrated load at the middle to the uniformly distributed load.

Multiscale stochastic Homogenization is studied for quasilinear hyperbolic problems. We consider the asymptotic behaviour of a sequence of realizations of the form ¶2uw/¶t2-div (a(T1 (x/e1)w1, T2(x/e2)w2, t, Duwe))-D(¶uwe/¶t)+ G(T3(x/¶3)w3, t, ¶uw/¶t) = ¦. It is shown, under certain structure assumptions on the random maps a (w1,w2,t,x) and G(w3, t, h), that the sequence {uwe} of solutions converges weakly in Lp (0, T, W1,P0(W)) to the solution u of the homogenized problem ¶2u/¶t2-div (b(t, Du))-D (¶u/¶t)+Ḡ (t, ¶u/¶t)= ¦.

The present paper investigates the microstructure and macrostructure of a newly Mn-25Ni-5Cr (%wt) (Mn70) alloy during Homogenization. The structure was analyzed by optical microscopy, energy dispersive spectroscopy and differential thermal analysis. The results show that dendritic segregation exist in Mn70 alloy ingot. The inter dendritic regions are rich in Ni and Cr and depleted in Mn. Macrostructure of Mn70 as -cast alloy consist of three zone: chill, columnar and equiaxed. For elimination of segregation during solidification various heat treatments were performed. For complete elimination of dendrite microstructure of casting alloy Homogenization heat treatment was done at 900oC for 10-hour our studies show that by increasing the Homogenization temperature to 1000oC can decrease the holding time, but, our studies indicates that for complete elimination of macro segregation and columnar to equiaxed transition 15-hour heat treatment at 1000°C is necessary. According to the obtained results, the dendritic microstructure, inhomogenity of macrostructure and segregation of alloying elements can be reduced by heat treating at 1000oC for 15-hour remarkably.

The concept of local Homogenization is employed for estimation of the relative permittivity scalars in copper Sculptured Thin Film (STFs). Three absorption transitions of dielectric to metal occur in the copper STFs. These transitions reduce to two in columns with circular cross section, when the volumetric fraction of metallic particles increases from zero to unity. The first transition occurs at low volumetric fraction of metallic inclusions and the other two transitions appear at high volumetric fraction of metallic inclusions. The influence of the column shape factors on the absorption transitions of dielectric to metal is also reported.

One of the most problem during solidification of ductile iron is segregation of alloying element. Segregation of alloying element decreases mechanical properties of ductile iron and austempered ductile iron. In this research, alloying element profile as a function intergraphite distance was studied. Homogenization of ductile iron using partial melting is carried out, for first time, to homogenize the distribution of alloying element in the matrix of ductile iron. Results of image analyzer for homogenize and austember specimen showed that Homogenization using partial melting against conventional Homogenization, is very effective to uniform microstructure of ductile iron. The results show that morphology of graphite before and after Homogenization using partial melting has minor effect on the morphology of graphite.