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.

Purpose: The science of interpretation, as the most important science responsible for understanding the Qur'an, needs to be methodized and updated so that the teachings of the Qur'an can be used easily for all classes of people. In the present study, the meaning of "future research in interpretation" is the ability to create desirable models for more efficient interpretation in the future, by using scientific tools, creativity and relying on the foundations and rules of interpretation and compensating the damages of interpretation in the past.Method: This research, with descriptive analytical method, answers the question, what are the fields and requirements of future research in interpretation? Findings: The results of the current research are based on the fact that special attention to the Qur'an, as the most important source of interpretation, rationality and methodical consideration in interpretation, attention to the prerequisites of interpretation, interpretation based on the requirements of the time, the need to pay attention to thematic interpretation, studying on the history of interpretation and observing the manners and conditions of interpretation are one of the most important requirements of interpretation in the future. Results: Considering the developments that will take place in the field of knowledge, methods and expectations from science in the future, the interpretation will also change. For this reason, in order not to cause various damages to the interpretation of the Qur'an, it is necessary to pay attention to the various contexts, principles and requirements of the interpretation of the Qur'anic commentators and scholars.

In the present study, the main purpose is the qualitative study on garbage collection in Tehran city. It has been done by qualitative research method. Semi-structured interview and purposeful sampling techniques were used in data collection. To do this, 15 people were interviewed and the sample size in the present study was determined based on theoretical saturation. Thematic analysis was used to analyze the data. Theme analysis was performed at 4 levels of primary, main, central and core themes. A total of 184 initial themes were extracted from all interviews. In the main coding stage, the following 9 main themes were merged. Escape from poverty in the origin and the inevitable choice of inferiority, society's view to garbage collectors, and high stress, strengthening the cycle of academic reluctance and illiteracy, physical and mental torment, unknown horizon and confusion of the Khojies, legal ambiguity and customary definitions and contracts, complaints from relevant institutions, the entry of the mafia and the formation of rent and corruption. Finally, these themes fall into two categories of social harmfulness of recycling and institutional exclusion and illegallity of the status of garbage collectors in the second distrect in the form of the core theme of the structure of socially harmful and institutionally illegal, waste phenomenon explained..

Juniper is the most important native conifer in Iran. Juniper as one of the most resistant tree species to extreme conditions, frost (up to -40°C) and drought, plays important role in mountainous regions of Iran. In this study, by investigation on qualitative and quantitative characteristics of essential oils ofleaves and berries (female cones), the effects of environmental factors were studied on metabolism of secondary products. The volatitale constituents of the Leaves and berries of male, female and male-female trees isolated by steam-distillation were analyzed by GC-MS.Results indicated that the amount of essential oil in berries is higher than that in leaves. Seasonal alteration of essential oil of berries differs from leaves. The essential oil of berries increase during growth period, however decreased in leaves. Besides drying has increasing effect on essential oil. In total 32 terpenoidic components were found that a-pinene, limonene, trans-verbenol, cisverbenol, verbenone, g- elemone and elemol were the important ones. a-pinene up to 70% of essential oil content was the highest component. Seasonal alteration of each component was very variable.Drying effect can be valuable for isolation of components and commercial applications.

In this study, a new metallic damper, the Corrugated Honeycomb Damper (CHD), is presented. The CHD is designed for ease of manufacturing and implementation in various structures, with a stable energy dissipation characteristic when subjected to lateral loading. The basic configuration of the CHD consists of two steel plates that are bent to form trapezoidal corrugations. The plates are then welded together along the bent lines to build the honeycomb geometry. To investigate the behavior of the CHD, a closed-form expression for the elastic stiffness was first obtained using the matrix analysis method. A verified Numerical model was then developed in ABAQUS software to study the non-linear behavior of the CHD, considering both material and geometric non-linearity as well as the potential for ductile steel damage. A comprehensive parametric study was performed, analyzing 12 CHDs with different geometric characteristics, and evaluating both monotonic and cyclic responses. Force-displacement and cumulative dissipated energy curves were extracted, and relevant elaborations were presented. Additionally, the equivalent stiffness and equivalent damping of the CHDs during cyclic loading were calculated, taking into account the principles of dynamics of structures. The results demonstrated that the CHD has stable and symmetric dissipative loops of energy, and that increasing the depth and thickness of the CHD can enhance its energy absorbing and load bearing capacities. Minimizing the width of the damper can fatten the hysteresis loops, but may also affect the ductility of the damper. Recommendations were given for the total height of the damper and the angle of bents to maintain stable hysteresis loops with respect to the target drift of the CHD.

Purpose: Managers are one of the important elements of an organization, for this reason, in order to draw the future of the organization, it is necessary for the planners to specify the conditions of their selection and appointment. Therefore, the current research has been done with the aim of identifying and analyzing the components of selecting future principals.Method: In this research, comparative and benchmarking method is used as a prospective approach. This approach is based on the belief that today's advanced organizations/countries can be considered as a model for the future of another organization/countries in their respective subjects. For this, first, the fields of comparison and benchmarking were determined using Brody's four-step comparison method; then the countries of Canada, Finland, Australia, South Africa, and Japan were selected according to the qualitative balance value in the international advanced TEAMS test, human development index, life quality index(health, instruction, and welfare), education quality index, and other scientific-scholarly indexes; finally, by extracting the criteria for the selection and appointment of principals through content analysis and comparison with Iran, the proposed framework for Iran has been presented.Findings: A total of 61 components for the selection of secondary school principals were identified from among the studies conducted in the selected countries in this article. By extracting the commonalities and differences of each of the components among the countries, it was found that the highest index of manager selection and appointment belongs to Japan and the lowest one is related to Finland.Conclusion: There are similarities between the components of selection of principals of secondary schools in Iran and selected countries. In Iran, special attention should be paid to important components such as adherence to religious principles, appropriate personality traits, creativity and innovation, motivation to develop capabilities, professional growth, power of supervision and accountability, social image, leader skills, and purposefulness and foresight.