---

Histopathological and pathomorphological effects of 15 ppb mercuric chloride on Persian sturgeon, Acipenser persicus, were investigated using histological and electron microscopy observations. Light microscopy showed that the gill epithelial hypertrophy, wrinkling and hyperplasia in lamellar epithelia and lamellae fusion occurred after 48 h of exposure. Gill epithelia also showed occasional necrosis, which had almost been completed and blood emerged from the capillaries. However, occasional necrosis in some regions of the filament, both with blood emerging and with no bleeding, was observed by using electron microscopy. These injuries were well observed in inter-lamellar regions of the filament and also wrinkling of the lamellar epithelium. Ultrastructural observations showed some cellular disorders in gill epithelium of the Persian sturgeon, A. persicus, fry. In addition, increase in apical vesicles of the chloride cells and necrosis in apical surfaces of some chloride cells, hypertrophy and necrosis of the chloride cells’ mitochondrion and endoplasmic reticulum also were some of the other cellular disorders observed through transmission electron microscopy. In conclusion, the gills of A. persicus fry were sensitive to low concentrations of inorganic mercury (HgCl2).

---

---

Analysis of genetic diversity of Fusarium verticillioides populations concludes different levels of information in management of crown and root rot disease in corn farms. Simple sequence repeat (SSR) markers were used to determine genetic structure and estimate genetic diversity in 77 F. verticillioides isolates from major producing areas in Ilam province, Iran such as: Dehloran, Mosiyan, Dasht Abas, Mehran, Eivan, Holeylan and Darreh Shahr during 2016 - 2017. Nine microsatellite (SSR) primer pairs revealed that the average number of alleles in populations were 34, the number of alleles in populations varied from 27 alleles in Dehloran and Mosiyan as the lowest to 40 alleles in Darreh shahr as the highest. Observed alleles (N_a) number and effective number of alleles (N_e) were higher in Mehran (N_a = 1.860; N_e = 1.463) compared to other populations. The genetic diversity (H_e) was higher in Holeylan (H_e = 0.284) and Shannon's information index (I) was also higher in Mehran (I = 0.436) but lower values were estimated for Mosiyan (H_e = 0.195; I = 0.303). The lowest genetic distance was found between Dehloran and Mosiyan (0.013) while the highest genetic distance was revealed between Dehloran and Darehshahr (0.139). Total gene diversity (H_t) and gene diversities between subpopulations (H_s) were estimated at 0.292 and 0.249 respectively. Gene diversity attributable to differentiation among populations (G_st) was 0.147, while gene flow (N_m) was 2.890. Cluster analysis based on UPGMA showed the lowest genetic distance between Dehloran and Mosiyan and then Dasht abas. The dendrogram indicated a high genetic distance between Darehshahr and the six remaining populations. Results from this study will be useful in breeding program of crown and root rot resistant cultivars and developing control methods for this disease. 

---

Vibration control of large flexible structures in new dynamic systems has significantly encountered with many challenges. In this area, there are several approaches of vibration control implemented on complicated dynamic systems in which the change of vibrational characteristics with the time of process leads to performance violation. In this paper, regarding the estimation of undesired vibration frequency of a flexible structure, input control of the dynamic system is reconstructed. In this regards, the input of the dynamic system is made to minimize the magnitude of the vibration. This strategy in which the control input is constructed by means of undesired vibration frequencies is similar to use of anti-viruses in medicinal approaches. The proposed control strategy is implemented on yaw channel of a flexible sounding rocket in order to reduce the destructive effects of bending vibration. The system responses show the effects of the vibration on the yaw channel of the system are significantly decreased.

---

Aerospace Launch Vehicles (ALVs), used for launching artificial satellites and space stations to Earth orbits, usually encounter with failure in navigation systems . In these cases, survival of an ALV during accurate payloads injection in orbits is one of the most critical issues for Guidance and Control systems.An important challenge for safety of Aerospace Launch Vehicle (ALV) is their reliability against all types of faults. There is a requirement for on-board fault detection without deteriorating the performance of ALV. In this paper, a new software sensor is proposed for fault detection and compensation based on symmetrical behavior of the yaw and pitch channels of an ALV. For this purpose, using identification techniques on the yaw channel, a new software sensor is developed as an online rigid dynamic predictor for the pitch channel. The proposed software sensor is employed to generate the residual of estimation error as an indicator of predefined faults. The main novelty of this software sensor is online tuning of the virtual sensor against unforeseen variations in the parameters of the vehicle. Robustness of the new control system in the presence of asymmetric behavior is investigated. The efficiency of the proposed fault tolerant method is illustrated through simulations.

---

Flexible solar panels of a satellite during a maneuver get excited and vibrate. Such vibrations will cause some oscillatory disturbance forces that affect the satellite rigid body. Vibrations cause cracks in flexible solar panels and these cracks, because of fatigue, make panels fracture. Moreover, satellite rigid body which does accurate works like capturing picture of earth surface or sending information to earth will be disturbed as a result of vibration. Therefore it needs to be prevented against resonance. In this paper, dynamic equations of a satellite including cubical rigid body are extracted, then with combination of ANSYS and ADAMS softwares, the model is simulated and its responses has been compared with analytical model. New control strategy for reducing the vibration of flexible bodies of the multi body system, includes rigid and flexible bodies, is proposed. With eliminate oscillation from rigid body angular velocity, vibrations amplitude of flexible parts will be reduced. For this purpose, an adaptive control system and a notch filter is used to eliminate the oscillation of measurement procedure caused by the vibration of flexible solar panels. Adaptive control system responses with considering resonance and without resonance, is shown and merits of this method is evaluated.

---

Reaction wheels are angular momentum exchange devices used to stabilize the position of the satellite and maneuvering. This actuator can change the momentum of the satellite to change the attitude of the system. During the process of operation, noise and disturbances arisen from the unbalancing of the wheels lead to inconvenient performance of the reaction wheels. Several works have been presented for active noise cancelation in these devices. But, the practical tools of signal processing such as filter banks and wavelets which used for offline de-noising are samples of very useful noise cancellation methods. If these toolboxes are employed for online de-noising these signal processing approaches are applicable for noisy systems such as reaction wheels. The main challenge of this strategy is delay arisen from the signal processing and this is inevitable. In this paper, a strategy of online wavelet de-noising is designed and proposed for noise cancellation in a reaction wheel. In this regards, for considering the delay compensation the method of Smith predictor is used to lead the delay of the process out of the closed loop control system. The accuracy of this algorithm requires an estimate of the system dynamics and the understanding of the delay system. According to the use of the FIR filter delay can be fully calculated. The recursive least squares used for identification reaction wheel as an estimate of the system.

---

In this paper, in order to reduce a landing gear vibration two adaptive control systems are designed considering the landing and taxi phases. For this purpose, 6 degree of freedom equations of motion of the landing gear and the related transfer functions are extracted. A reduced order model of the overall transfer functions are given as a result of complicated dynamic model. A Lyapunov based model reference adaptive control is designed to absorb the vibration of front wheel of the landing gear at touchdown. In addition, a minimum variance adaptive controller is designed and implemented on the system to reject the band level disturbances during the taxi phase. The band disturbances are modeled as a colored Gaussian noise and the system parameters as well as noise characteristics are estimated using extended least square approach. Both control systems are investigated to assess the best performance. Numerical simulations of the system in Matlab/Simulink environment show the preferences and satisfactory performances of the proposed vibration control systems. These results are calculated against various inputs including model reference adaptive control and minimum variance approaches

---

In this article, a form of Boltzmann-Hamel equations (Lagrange’s equations in terms of quasi-coordinates), different from the latter’s standard form and avoiding its structurally inherent complexity, is derived based on which a general algorithm for the dynamics modeling of open-chain terrestrial and space robots with an arbitrary number of rigid elements is presented. This form of Boltzmann-Hamel equations is shown to be particularly advantageous in terms of not requiring the determination of the kinetic energy as a function of generalized coordinates and quasi-velocities, representing generalized forces in terms of body basis vectors and offering a panoramic view of the dynamics of the systems. In the act of developing the algorithm, three highly useful kinematic identities are derived via a comparison between the single rigid body equations derived from both the standard and the proposed form of Boltzmann-Hamel equations. These identities are then used to greatly simplify the final dynamics model of both systems. Finally, the equations of motion for a two-link terrestrial robot is derived using the proposed algorithm and simulation results in MATLAB are compared with the model of the system in ADAMS to validate the model.

---

In this paper, the effect of government intervention in the banking sector (financial repression) on banks’ financial stability is investigated during 2001-2013. To measure the index of government intervention in the banking sector, three variables including real interest rate, credits directed by banks and government debt to banks are combined using principal component analysis. Furthermore, the z-score index is applied to measure the financial stability in the banks. Data are extracted from balance sheets and income statements of the banks. Results from a panel of 14 banks show that the intervention of government in the banking sector is of significantly negative effect on financial stability of these banks and therefore increases their financial vulnerability. Moreover, an increase in size of bank improves the financial stability, but higher debt-to-asset ratio increases the banks’ financial vulnerability.

---

In this paper, according to flight devices categories, advantages and features of quadrotors and its performances are investigated. Then, the main challenges in quadrotors control and stability in the presence of obstacles have been considered in such a way that the system crosses the maximum number of obstacles in the best distance and time. For this purpose, the equations of motion of the system are derived and a controller for command tracking is designed without obstacles based on sliding mode method. The simulation results of the controller performances are given in the paper. In continuous, trajectory planning for crossing the system from the obstacles in alternative positions is presented and the quadrotor with the designed control system are simulated using the designed trajectory. The preference of the proposed trajectory planning is that the system can cross the number of obstacles in alternative positions in minimum time and using fewer sensors. Because of free shape of designing method and alternative initial velocity, the proposed method are applicable for piecewise trajectories. As a result of considering the drag force, the proposed approach is more successful in the various problems.

---

         The relationship between the competition law and intellectual law might be considered from different directions. There are many discussions about the interaction or conflict between these fields of law. Some schollars are believe that the rules, which are applicable in these fields are in conflict; because one of them has formed for preventing the monopolies and supervising on the economic agents’ activities to prevent the harm that can be imposed to competition in the market, and the other supports the exclusive rights arising from the intellectual properties. On the other hand, but some scholars believe that there are no conflicts between these fields. But the evidence of the last theory might be challengeable, because some scholars consider the competition law over the intellectual property law due to its features, although others believe that there is an interaction between these fields. Assuming the interaction theory or conformance of intellectual property law from the competition law, some questions will arise, and we have to find suitable answers for them: "What is the effect of domination of competition law over the intellectual property law on the general rules of contracts and their principles?" Do the general rules of contracts follow the mentioned law? Is the interaction between intellectual property law and compeptition law considered as conspiracy against the last principles?" and If it was necessary for supporting the competition, can we force the owner of exclusive right to transfer the right or to accept other's usage, of it?      
*  Corresponding author’s E-mail: rkhoshnodi@yahoo.com

---

Corruption is a historical and global phenomenon, which exists in both developed and developing countries. Various cultural, social, economic and political factors affect corruption. Among these, security of property rights and democracy influence financial corruption. In this study, using a panel data system and generalized least squares method, the interactive effects of democracy and security of property rights on corruption are examined in 59 selected developed and developing countries during 2005-2014. The findings of estimations with various indicators of democracy (Polity2, FH, and Political Rights) show that whereas protection of property rights reduces corruption in any political environment, the presence of democracy in society cannot reduce corruption alone. Democracy should be accompanied by high levels of security of property rights in order to affect financial corruption negatively. In addition, while protecting property rights reduces corruption in any political environment, it is more effective against corruption at high levels of democracy.

---

---

Chickpea wilt caused by Fusarium oxysporum f. sp. ciceris is one of the major yield-limiting factors in chickpea, particularly in west and northwest of Iran. Simple Sequence Repeats (SSR) were used to determine genetic structure of Fusarium oxysporum f. sp. ciceris populations from three infected areas located in west and northwest provinces of Iran during 2016-2017. A set of six microsatellite primer pairs revealed 35 alleles in each locus with an average of 5.83 per locus. The PIC value varied from 0.20 (FOAG11) to 0.39 (FODF7) with an average of 0.27 per locus. The average number of effective alleles (N_e), Number of private alleles (N_a), allelic variability per locus (H), Shannon's Information Index (I) and percentage of Polymorphic Loci (%PL) in three populations were 1.33, 1.97, 0.2208, 0.357, and 74.29, respectively. The average genetic distance was calculated among the three populations. Nei’s pair-wise genetic distances between the populations varied from 0.0202 to 0.98. The total gene diversity (H_t) and gene diversities between subpopulations (H_s) were estimated to be 0.2208 and 0.2079, respectively. Gene diversity attributable to differentiation among populations (G_st) was 0.0585, while gene flow (N_m) was 8.0412. The AMOVA of genetic variation in Fusarium oxysporum f. sp. ciceris populations revealed that 5% of the variance occurred among populations and 95% within populations. PhiPT value was 0.054. The lowest genetic distance was found between Kurdistan and West Azerbaijan with Lorestan populations, while the highest genetic distance was observed between Lorestan and Kermanshah populations.