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Aims: The present study aimed to investigate the determinants of COVID-19 preventive behaviors among women of reproductive age in Urmia using a behavioral change model.
Instrument & Methods: The present descriptive-analytical study examined 400 women selected by the snowball and convenience sampling method. Data were collected using a valid and reliable electronic researcher-made questionnaire consisting of four sections (demographic characteristics, knowledge, model constructs, and preventive behaviors) and analyzed by the descriptive and inferential statistical methods by SPSS 16.
Findings: There was a positive correlation between COVID-19 preventive behaviors with self-efficacy (p<0.001, r=0.68), knowledge (r<0.26, p<0.001), cues to action (p<0.001, r=0.29), perceived benefits (p<0.001, r=0.43), perceived susceptibility (p=0.002, r=0.15), and  perceived severity (p<0.001, r=0.20), and a negative and significant correlation with perceived barriers (p<0.001, r=-0.32). The constructs of the health belief model predicted 50% of the variance of preventive behaviors, and the self-efficacy construct (p<0.001, β=0.5388) was the strongest predictor.
Conclusion: Given the effective role of the research model in explaining the determinants of the COVID-19 preventive behaviors, the health belief model (HBM) and effective constructs can be used in educational planning and interventions.

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Centrifugal pumps performance is highly affected by working fluid viscosity. So, optimization of such pumps for pumping of viscose fluids is very important. In the present paper, multi-objective optimization of the centrifugal pumps is performed to obtain optimum impellers for pumping fluids with various viscosities at different volumetric flow rates. In this way, theoretical head and impeller hydraulic losses are considered as objective functions. Design variables defined in this optimization problem are passage width of impeller and outlet angle of blade. Diagrams of Pareto fronts and Pareto sets are extracted for different viscosities and different volumetric flow rates. Some trade-off optimum design points are selected from all non-dominated points using three different methods namely break point, TOPSIS and near to ideal point. Such methods are defined completely and employed to achieve compromising point successfully. Obtained optimum points contain interesting results which cannot be achieve without using proposed multi-objective optimization approach.

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Heat pipe is an effective device for heat transferring. Using nanofluid as working fluid can significantly increase heat pipe thermal performance. But rate of the performance improvement, is dependent on parameters of the suspended nanoparticles in nanofluid. In this article, for the first time by considering nanoparticle volume fractions and diameters as design variables and the difference between the wall temperature of evaporator and condenser and liquid pressure drop as objective functions, the heat pipe performance has optimized. The used heat pipe is a cylindrical heat pipe with nanofluid as working fluid. Heat pipe thermal performance while using nanofluid has modeled by CFD method and then GEvoM has used to relate between design variables and objective functions. Using the modified NSGAII approach, pareto front has plotted and the values of recommended optimum points has obtained by mapping method. Recommended design points unveil interesting and important optimal design principles that would not have been obtained without the use of a multi-objective optimization approach.

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Fractional calculus is a branch of mathematics which in recent decades has been of great interest to scientists in various disciplines, including engineering. One of the applications of this branch in engineering, is in modeling the viscoelastic materials using fractional differentiation. In this article, by inserting fractional calculus as a viscoelastic material compatibility equations in nonlocal beam theory, a viscoelastic Euler-Bernoulli nano-beam with different boundary conditions at two ends, has been modeled. Material properties of a carbon nanotube is considered and two methods, pure numerical and numerical-analytical have been used for solving obtained equations in time domain. Main method is completely numerical and operator matrices used in it to discrete equations in time and spatial domain. Second method is introduced for validation of pervious method’s answers. In this method equation of system reduced to an ordinary differential equation using Galerkin and obtained equation solved using a numerical direct integrator method. Finally, in a case study, the effects of fractional order, viscoelasticity coefficient and nanlocal theory coefficient on the time response of the viscoelastic Euler-Bernoulli nano-beam with different boundary conditions have been studied.

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Significant improvements in mechanical properties of polymers reinforced with nanoparticles at relatively low volume fractions, is caused that the use of polymer nanocomposites increase. The main reason for the increase in mechanical properties of nanocomposites is the presence of an interphase region between the nanoparticles and polymer matrix. In this work using a unit cell-based micromechanical model, the percolation behavior of the mechanical properties of nanoparticle reinforced polymer nanocomposites is investigated. The Representative Volume Element (RVE) of nanocomposites consists of three phases including nanoparticles, polymer matrix and interphase. The RVE is extended to c×r×h nano-cells in three dimensions and the state of dispersion of nanoparticles into matrix is random. Effects of interphase region including its thickness and elastic modulus and nanoparticle geometry on the percolation behavior of the nanocomposite are studied. Results show that with decreasing the nanoparticle size or increasing aspect ratio of nanoparticle, critical volume fractions decreases. The predicted results of the present micromechanical model are in good agreements when compared with results of the other micromechanical model. The herein reported results could be useful to guide the modeling and optimal design of nanocomposite reinforced by nanoparticles with the highest economic interest.

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Using molecular dynamics simulations, the structural properties and vibrational behavior of single- and double-walled carbon nanotubes (CNTs) under physical adsorption (functionalization) of Flavin Mononucleotide (FMN) biomolecule are analyzed and the effects of different boundary conditions, the weight percentage of FMN, radius and number of walls on the natural frequency are investigated. As the functionalized nanotubes mainly operate in aqueous environment, two different simulation environments, i.e. vacuum and aqueous environments, are considered. Considering the structural properties, increasing the weight percentage of FMN biomolecules results in linearly increasing the gyration radius. Also, it is observed that presence of water molecules expands the distribution of FMN molecules wrapped around CNTs compared to that of FMN molecules in vacuum. It is demonstrated that functionalization reduces the frequency of CNTs, depending on their boundary conditions in vacuum which is more considerable for fully clamped (CC) boundary conditions. Performing the simulations in aqueous environments demonstrates that, in the case of clamped-free (CF) boundary conditions, the frequency increases unlike that of CNTs with fully clamped and fully simply supported boundary conditions. The value of frequency shift increases by rising the weight percentage of FMN biomolecule. Moreover, it is observed that the frequency shifts of SWCNTs with bigger radius are more considerable, whereas the sensitivity of frequency shift to the weight percentage of FMN biomolecule reduces and this is more pronounced as the simulation environment is aqueous.

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Dromedary and Bactrian camels are two species of camel in Iran that have ecological adaptation to cold and hot desert area, respectively. They play an important role in the life and food security of nomadic tribes. The present study was conducted to investigate genetic diversity of 180 Iranian camels using microsatellite markers. In a panel of 20 microsatellite markers, we observed 214 alleles with a mean number of 10.7 alleles per locus. All loci exhibited PIC values more than 0.7. The genetic differentiation values (F_ST) per locus was different from 0.01 to 0.039 with an average of 0.021 across all loci. The estimate of genetic differentiation level between all Iranian camel populations in this study was low (F_ST: 0.008-0.021). High gene flow between populations was also observed. Phylogenetic tree illustrated that the highest genetic distance was between Bactrian and dromedary camel from YaD. However, the results of the present microsatellite analyses showed close genetic relationship in the studied populations. All of the population-locus combinations showed significant deviations (P< 0.01) from Hardy-Weinberg equilibrium.
 

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Regarding the importance of bridges as one of the most critical infrastructures, their maintenance, and health monitoring is of high priority. Interaction between the moving vehicles and bridges is amongst the fields of study that have been investigated in depth by numerous researchers in the field of bridge engineering. Among different proposed methods of structural health monitoring of bridges, the indirect methods that do not need the healthy structure response are of high interest because of their ease and low maintenance costs.
The response of a moving mass passing through a bridge can be analyzed for the indirect prediction of the beamchr('39')s mechanical properties. This can lead to the detection of possible damages or degradations in the structure. By mounting high precision accelerometers on the moving vehicle and recording the corresponding signals, it is possible to capture the sudden change of mechanical properties pertaining to the existence of damage in the bridge.
In the current study, an FE code is developed in order to analyze the moving vehicle response. In this code, the bridge is modeled as an Euler-Bernoulli beam, and a complete model comprising stiffness and damping of the suspension system of moving vehicle is built. In order to verify the results of the code, comparisons are made with the outcomes of modal analysis. The sensitivity of the FE results with respect to the number of elements is examined. These comparisons clearly show that both methods reach the same values for a sufficiently high number of elements for the moving vehicle response.
Following verification of the code, a brief review of the concepts underlying the variational mode decomposition (VMD) method is given for a self-contained representation. The VMD can be used to decompose a signal into a number of signals with limited bandwidth. Although it has found many applications in different signal processing cases (e.g. in the field of electronics, mechanical vibrations of machines, or even in the analysis of economic and financial time series), extending its application to the field of structural health monitoring is entirely a recent and ongoing topic of research.
After the introduction of the VMD, damage in the beams is implemented by using fracture mechanics concepts. Different damage scenarios are applied in order to check the reliability and robustness of using VMD as a damage detection method. These include different damage locations (single, dual) and damage severity represented in terms of crack depth. By having a reliable means for the analysis, the novel variational mode decomposition (VMD) is applied to analyze the signals recorded from the vehiclechr('39')s back axel in search of any possible irregularity in the signal properties. By monitoring results attained for several damage cases, the following conclusions can be given:
• The variational mode decomposition (VMD) can highlight the presence of irregularities in mechanical properties that can be reached directly from decomposed signals.
• The location of these signal irregularities coincides with the presumed location(s) of the crack(s).
• The severity of the signal irregularity and corresponding instantaneous energy is proportional to the degree of damage imposed on the beam. 
• The moving vehiclechr('39')s natural frequency plays an essential role in the bridgeschr('39') structural health monitoring. The signal processing results exhibit amplified abrupt changes for the vehicles with the natural frequencies close to the beamchr('39')s fundamental frequencies.  
Regarding the above conclusions, analyzing moving mass response with the VMD can be a reliable damage detection technique.