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Mites of the families Parasitidae and Laelapidae (Acari: Mesostigmata) are among the most common and widely distributed mites of the suborder Gamasina. During 2015-2017, fauna of parasitid and laelapid (Acari: Mesostigmata) mites from domestic animal manure collected and surveyed in Khuzestan Province, southwestern Iran.Totally, four Parasitidae species belonging to three genera and seven Laelapidae species belonging to four genera collected from domestic animal manure in Khuzestan Province. Among them, Cornigamasus ocliferius Skorupski & Witaliński, 1997 is a new record for mite fauna of Asia and Androlaelaps projecta Furman, 1972 is a new name for mite fauna of Iran. Four species are new to Khuzestan Province fauna as well. We also recorded six manure-associated species which have never been previously reported from manure in Iran. Parasitus fimetorum (Berlese, 1904) was the most frequent Parasitidae species among our records. The mites distribution and habitats data in Khuzestan Province are provided for all of the species, together with some taxonomic and bio-ecological notes.

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In this research, production planning for refinery production processes (multi-stage, multi-production) was modeled with two approaches: crisp and fuzzy. The purpose of this article was to answer this question that which approach (crisp or fuzzy) has a better answer for production planning. To answer this question, at first, one multi- stage multi- production crisp linear mathematical model for a 24-hour period was designed. Then its fuzzy model was organized and finally the models were tested in a research sample. The results from fuzzy and crisp models showed the improvement of optimal answer in fuzzy model rather than crisp model. Also it should be mentioned that the presented model in this research can be applied in other refinery production processes (multi-stage,multi-production).So it is recommended that for mathematical modeling of production planning, Corresponding vague and ambiguous factors should be measured through fuzzy logic and this kind of modeling should be used as a base for production planning. Disregarding this subject is the shortcoming of the previous models (which are mentioned in Introduction).

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Numerical modeling of electro-osmotic flow in heterogeneous micro-channels using two different models is presented in this article. For the through modeling of such flows, the coupled equations of Navier-Stokes, Nernst-Planck and the Poisson-Boltzmann are solved for the flow field, electric charges transport and electric field, respectively. Numerical solution of these equations for the heterogeneous micro-channels is complicated and difficult. Therefore, simple and approximate models such as Helmholtz-Smoluchowski have been proposed in which the solution of Poisson-Boltzmann, Nernst-Planck are neglected and the effect of the electric field on the flow field is applied through a prescribed slip boundary condition at the walls of micro-channel. The electro-osmotic flow fields within the heterogeneous micro-channels are usually complex and contain the vortex region that is ideal for mixing purpose. Hence, in this paper, the micro-channels designed so that they are capable to serve as micro-mixers in the mixing applications. For the micro-channels proposed here, the flow fields are obtained both with approximate modeling and the full simulation of electro-osmotic flows so that a comparison can be made to discuss the accuracy of the approximate model. The results of this study can be used to model the electro-osmotic flow field within heterogeneous micro-channels.

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Mixing within electrokinetic micromixers is studied numerically in this article. Micromixer studied here is simply a heterogeneous parallel plate microchannel which is imposed to the electroosmotic flow field. For the through modeling of such flows, the coupled equations of Navier-Stokes, Nernst-Planck, Poisson-Boltzmann and concentration equations are solved for the flow motion, electric charges transport, electric field and species concentrations, respectively. Numerical solution of these set of equations for the heterogeneous microchannels is complicated and difficult. Therefore, simple and approximate model such as Helmholtz-Smoluchowski has been proposed which is basically appropriate for the case of microchannels with the homogenous properties on the walls. Validation of Helmholtz-Smoluchowski model is well-examined for the prediction of two dimensional flow fields, yet its applications is rarely validated for the prediction of concentration field and mixing performance. In this article mixing due to electroosmotic flow field is investigated using Nernst-Planck equations as well as Helmholtz-Smoluchowski models and the accuracy of the Helmholtz-Smoluchowski model is evaluated. Comparison of the results indicates that for the proper conditions, approximate model can predict the mixing performance accurately along the micromixer length.

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In this article numerical simulation of electroosmotic flow in heterogeneous microchannel is performed using approximate model of Helmholtz-Smoluchowski in which the effect of electric field on the fluid flow is applied through a slip boundary condition. Solving the concentration equation, the mixing performance of microchannels with heterogeneous zeta-potential is studied both qualitatively and quantitatively. This study shows that combining the electroosmotic and pressure-driven flows in a single microchannel with proper arrangement of the heterogeneities can easily lead to design of electroosmotic micromixers with adjustable mixing performance. The mixing behavior of such micromixers is dominated by the arrangement of zeta-potential distribution as well as the applied external pressure drop. In this article we introduced relative mixing performance and mixing capacity rather than well-discussed factor of mixing performance in order to perform a thorough analysis of mixing. Using these factors, it is found that presence of heterogeneities has a small augmentation on mixing performance when the pressure drop is extremely small or large. Therefore, performance of micromixers with combined flow of electroosmotic and pressure-driven has an optimum point. Furthermore, it is seen that asymmetric level of the charge pattern is more effective on the mixing performance compared to absolute values of wall charges. This promises proper mixing even when surfaces with moderate zeta-potential are used in micromixer.

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The rigid steel connections were suffered severe damage because of low rotational capacity during earthquakes. Hence many investigations have been performed on the connections of steel structures. In order to prevent brittle failure of connections and damage of main structural members, steel slit dampers with uniform strip width are used in the beam-to-column connections. Slit damper is a plate or a standard section with a number of slits in the web. The remaining strips in the web of damper, dissipate the seismic energy with inelastic deformation absorption and also prevent seismic energy transmission to the main structural members. No special fabrication technique was involved in the slit dampers, thus the device can be easily used in practice. To verify the accuracy of finite element modeling, the obtained results of ABAQUS finite element software were compared with an experimental study done by Oh et al (2009). The analytical results have a good agreement with experimental ones and the average error is about 2%. According to the analyses performed in the ABAQUS, using steel slit dampers with uniform strip width is resulted in stress concentration at the ends of the damper strips, unbalanced distribution of Von-Mises stresses along the strips length and low participation of middle parts of slit damper strips in the energy dissipation. Therefore, to resolve these problems and energy-absorbing area rise in the end parts of strips, elliptic slit damper is proposed and compared with the previous investigated slit damper. Slits dimensions of elliptic slit damper are calculated as such that both of present and previous slit dampers have the same weight. The objective of this paper is to improve the seismic performance of steel slit dampers. Nonlinear analyses are carried out in the beam-to-column connections equipped with slit dampers. Effects of geometrical and material nonlinearity are considered in the analyses. Nonlinear characteristics of steels are defined with stress-strain curves. Bilinear stress-strain curves are used for all steel parts except the slit damper which is defined with completed stress-strain curve. Plasticity behavior of steel materials is based on the Von-Mises yielding criteria. Loading protocol recommended by FEMA-350 is used for cyclic analyses. All parts of connection are modeled using shell elements except the split-T plates and the upper plate of slit dampers which are modeled using solid elements. The results of connections analysis under cyclic loading show that the proposed elliptic slit damper causes better distribution of stresses along the damper strips, better hysteresis performance and increase the amount of energy dissipation in the beam-to-column connection. Also elliptic slit damper leads to strength and ductility increment in the connection. Additionally, it is concluded that in the proposed elliptic slit damper compared to the slit damper with uniform strip width, the energy dissipation and the maximum plastic rotation of connection increase about 99.6 and 26.8%, respectively.

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The column members of moment frames are subjected to high axial forces as well as inelastic rotations during a seismic event. Estimating the boundaries of these simultaneous structural demands on the columns of special moment frames are one the aims of this research. These demands were evaluated in this research by performing a vast number of non-linear time history analyses on some archetype frames. Totally, eight archetype buildings were designed under two levels of spectral accelerations represent the Maximum Credible Earthquake (MCE) and the Design Earthquake (DE). Both geometric and material nonlinearities were taken into account. Far-field earthquake record set proposed by FEMA P696 was utilized in this study to conduct the required time history analyses. This set includes 44 individual seismic records with different magnitudes and other specifications. Each sample SMF was excited by each of the individual records with two different intensity levels referring to DE and MCE respectively. After performing numerous time history analyses, the boundaries and the characteristics of the axial force and the story drift ratio demands on columns were fairly stablished for the seismic events with MCE and DE intensity levels. It was proved that they might experience the axial force around 0.3 of their yielding capacity as well as the drift ratios up to 0.06. Moreover, based on the results of these analyses, a representative loading protocol was also developed for the column members of special moment frames because the effect of simultaneous change of the axial force demand on columns along with the change of plastic rotation in these members was neglected in all of introduced loading framework for these members. On the other hand, the utilized loading frameworks in different research studies were introduced quite arbitrarily and with no root in the real seismic demands of these structural members. Hence, a statistical approach implemented to extract the loading cycles based on the results of the mentioned non-linear time histories. This loading protocol includes cycles of varied axial force ratios as well as simultaneous cycles of lateral loading. Providing such a loading regime can pave the way to investigate the behavior of the columns of moment frames using more sophisticated numerical models that cannot be ordinarily employed to perform time history analyses under seismic records due to excessive computational costs. The overall response of steel columns may be dominantly affected by the local effects like as local bucking at large deflections. Hence, the response of some archetype individual columns was fairly investigated under the proposed loading protocol by utilizing continuum finite element simulations which are expected to be able to capture deliberately these kinds of local effects. The investigation not only revealed more on the details of the behavior of these members, but also proved the versatility of the proposed loading protocol in comparison to the previous loading procedures implemented on columns. In order to do so, the numerical models of the archetype columns were also loaded under the proposed lateral loading protocol besides constant levels of axial loading and the results of both cases were compared. It was shown that implementing a constant axial load besides the cyclic lateral cyclic loading may not be an appropriate loading framework and the results would not represent the seismic demands in these members accurately.

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In this paper, the stress intensity factor for an internal circumferential crack in a thick-walled cylinder has been determined. The cylinder has been subjected to an axisymmetric thermal shock on the outer surface according to the dual phase lag theory. The uncoupled, quasi-stationary thermoelastic governing equations have been assumed. The temperature and stress fields have been solved analytically in the Laplace domain and its Laplace inversion transform has been obtained numerically. Using weight function method, the stress intensity factor for mode-I has been extracted. Temperature, stress and stress intensity factor of hyperbolic and dual phase lag theories have been compared and the effects of heat flux and temperature gradient time relaxations on the temperature, stress and stress intensity factor have been studied. According to the results, the dual phase lag temperature distribution is different in comparison with the Fourier model. Also, the stress intensity factor for dual phase lag model is significant larger than Fourier one. Moreover, the maximum stress intensity factor in dual phase lag model occurs for a crack that the peak of stress wave reaches to its tip. Results show assumption of adequate heat conduction model for structure design under transient thermal loading is critical.

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In this article, some stylistic features of Khaqani's poetry have been analyzed in the rhetorical layer of the text. For this purpose, all compressed and extended images were analyzed and analyzed in terms of the source of the image and how the subject is related to the image. This is useful in several ways. First, the frequency of imagery sources in the text introduces us to the important categories of the poet's mind and thought, and on the other hand, the type of connection between the subject and the source of the image can be a sign of the poet's attitude and life experience with the world. Other topics such as the difference in the conceptual domain of the image between different types of lyrical, eulogy and judgmental poetry, identifying stylistic features and explaining the function of the image for the poet, are other categories that we have addressed in this article by mentioning the evidence.

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Choosing the right equipment in terms of price, performance and reliability, is one of the main challenges in the automation industry. Among these equipments, electric motors are the most important elements which are widely used in the industries. Electro motors selection is made according to certain rules and principles, and it is very important to know the governing conditions. Using amotor with less power than required will lead to system failure and a motor with much more power will result in extra costs. In this article, scientific selection of an electric motor for the bending process in an automation system has been discussed. Using real conditions of a manufacturer and available data in articles and books, the necessary relationships were extracted. 28 number of motors (among the available ones) were nominated in the first stage of preliminary monitoring. Then, by applying other prevailing conditions and characteristics, 3 motors with different powers selected for final investigations. Eventually, after using Simscape simulations & exerting less energy consumption criteria, the 5RK90GE-CW2ML2 motor (manufactured by Oriental Motor Company) was selected and was approved after satisfying the power, quality and safety conditions.