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This paper presents a new method to design optimal thrusters’ configuration for geostationary satellite in order to reduce the fuel consumption and increase the control accuracy. The thrusters configuration generally contains information about thrusters fixed on the satellite body structure, including their location, orientation. One important factor playing a key role in thrusters’ configuration design is satellite force-torque analysis. The proposed configuration, however, should lead to fulfill specified attitude maneuver when the set of force and torque produced by satellite thruster system is adequate. For this purpose, two optimization methods using genetic algorithm (GA) and differential evolution (DE) has been applied to determine the optimal thrusters configuration on the communication satellite body. The cost function employed to minimize both the fuel consumption and error generated by thrusters installation and uncertainties. Moreover, this work allows applying some different constraints in the proposed formulation including minimization of the thruster plume impingement effect on the satellite outer structure and on the solar arrays and the second one is the satellite dimension and geometry. Simulation results show that DE outperforms GA in terms of accuracy and CPU time. Effectiveness of differential evolution algorithm is illustrated in the paper when compared with GA results.

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In this paper, LQG/LTR controller is designed for attitude control of the geostationary satellite at nominal mode. Usage actuator in this paper is the reaction wheel and control torque is determined by the LQR regulator. Usage sensors in this article are sun and earth sensors and EKF are used for estimation of noisy states. LQR controller signal has good performance, if all system's states are considered in system output feedback. But this method is ideal and does not include model noise and sensors noise. Therefore, LQG and LQG/LTR controllers are designed based on the estimated states, and are compared with LQR controller. Controllers gain coefficients are obtained based on linearization about working point. It caused to robustness and similarity of LQG and LQG/LTR response. The results show that control overshoot of LQR is greater than the others.

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Sour-orange (Citrus aurantium) seed oil was extracted by ultrasound-assisted, heat reflux, and Soxhlet extraction methods and their physical (melting point, viscosity, specific gravity, refractive index, and color) and chemical (acid value, acidity, peroxide value, iodine value, saponification value, and ester value) properties were investigated. Results showed although that some properties of the sour-orange seed oil such as acid value, acidity, peroxide value, iodine value, melting point, viscosity, and color were affected by the extraction method but its other properties such as saponification value, ester value, specific gravity, and refractive index were not affected by extraction method. In addition, the results of this study indicated that the sour- orange seed oil has some advantages such as low free fatty acid, low acid value, low peroxide value, low melting point, high saponification value, and high ester value. Therefore, the sour-orange seed oil can be introduced as suitable edible oil.

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In recent years, many advances have been made in improving the biocatalytic activities of enzymes. Interaction of enzymes and macromolecules have important role in stabilization of enzyme’s structure and function. Lysozyme lyses the bacterial cell wall by splitting ß (1–4) linkages between N-acetylmuramic acid and N-acetylglucosamine of the peptidoglycan in bacterial cell walls. Tragacanth is a polysaccharide obtained from exudates of the species of Astragalus. It is a very complex heterogeneous anionic polysaccharide of high molecular weight. Tragacanth consists of two main fractions: a water-insoluble component called bassorin, and a water-soluble component called tragacanthin. The aim of this investigation was to attach tragacanthin (water-soluble component of tragacanth) to lysozyme by Maillard reaction. The covalent attachment of this hydrocolloid with lysozyme was confirmed by SDS-PAGE and ion exchange chromatography. The conjugates exhibited improved solubility, foaming and emulsion properties. In addition, thermal stability of lysozyme in this conjugate was increased significantly. According to these results, attachment of lysozyme to tragacanthin can increase the application of this hydrocolloid as a functional component and lysozyme as a natural antimicrobial component in food and pharmaceutical industry.

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Verjuice is a popular fruit juice mainly consumed as salad dressing. However, there is very little information regarding its characteristics. The objective of the present study was to determine verjuice and its concentrate physicochemical properties during storage at 4 °C. Firstly, verjuice characteristics such as pH, acidity, specific weight, density, total soluble solids, total solid, reducing sugar content, ash, rare minerals, vitamin C , phenolic content and antioxidant activity were evaluated. In the next phase variation of acidity, pH, total solid and colour parameter (L, a, b) and total phenolic content of pasteurized concentrate verjuice during 6 months storage at 4 °C were assessed. Findings revealed that not only verjuice has a high acidity value but also it is a good source of bioactives such as vitamin C, antioxidant and phenolics components. Storing the concentrate at 4 °C resulted in reduced acidity, phenolic content, parameter L and b but increased value of parameter a, and total solid.

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In this paper, multi-objective Genetic Algorithm has been employed to find the communications satellite optimal transfer trajectory from geosynchronous transfer orbit (GTO) to geosynchronous orbit (GEO) as the destination operational zone. Because of satellite high specific impulse, Orbital maneuvers are considered as impulsive maneuvers in this paper and its validation is verified by comparison of results with continues one. Number of intermediate orbits has been found in order to physical constraints. In this systematic approach, both minimum-time and fuel-saving using constant acceleration simultaneously as the problem strategy to find the optimal transfer trajectory between two orbits. Set of optimal trajectories are plotted in Pareto Front and transfer trajectory can be selected from these points. Finally, the results are compared with the results obtained using STK software and good agreement has been revealed. The satellite access to ground station (GS) is analyzed and optimal position for GS is found by defining lack of access and mass consumption as objective functions. Finally, disturbance torques induced by liquid apogee motor (LAM) is investigated and thrusters' fuel mass for this disturbance torque control is proposed.

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In this paper, a LQG/LTR controller is proposed for attitude control a geostationary satellite at nominal phase. Basically, proposed methodology includes three parts: LQR regulator, EKF, and loop transfer recovery. Controller design is based on the linearized equations of the spacecraft dynamics using reduced quaternion model. Reduced quaternion model solve uncontrollable problem in some subspaces in the linearized state space quaternion model using all four components of quaternion. Spacecraft actuators are reaction wheels and attitude determination sensors are sun and earth sensors. LQR controller is ideal and it doesn’t account for the model uncertainty and sensor noise and it uses the feedback of the full states. To consider the model uncertainty and sensor noise, we have designed EKF which is used by LQG and LQG/LTR controllers. Controller gain coefficients are obtained using a reduced quaternion model, and based on linearization around the equilibrium point and the natural frequency of the closed loop system. To increase the robustness of the design with respect to solar radiation disturbance, singular values of LQG are approximated to Kalman filter, in LTR section. The results demonstrate that LQG/LTR performance is better than LQG’s and LQG/LTR has a good robust stability margin with respect to disturbances.

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This research deals with configuration design and layout optimization of communication satellite. First, an approach is proposed to design the configuration of GEO satellite. Since propulsion subsystem in GEO satellite is the massive item, it has a significant impact on satellite configuration. Consequently, it is necessary to consider the propulsion subsystem influence on satellite configuration. Then layout design process of the satellite components which is one of the complex problems in engineering is performed. In this paper, in order to optimize the layout design of satellite components, the algorithm which consists of two stages, primary and detail layout, is proposed. In order to express geometric constraints mathematically, the Finite Circle Method (FCM) is used. For The mathematical expression of performance constraints, the distance constrains related to distance relationships between components have been developed. The hybrid optimization method is proposed to optimize layout design which is a combination of Simulated Annealing optimization and Quasi Newton methods. The optimization method validation is applied on simple test problem. Finally, the proposed algorithm for configuration and optimal layout design is implemented on communication satellite. The results show that product of inertial (objective function) are minimized and considered constrains of communication satellite are satisfied.

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The aim of this study was to prepare tortilla from oat flour and optimize the physical quality of the resulting product. Inactivated the lipase and peroxidase enzymes in the oat grains were processed during thermal process operation to prevent lipid rancidity and the oat flour was prepared. At the next stage, tortilla was prepared from oat flour.To improve the texture of tortilla, whey, gluten and mono di glyceride isolates were added to oat flour. The effect of the additives was investigated during tissue stress, fragility resistance and colorimetry tests. According to the results,with increasing gluten level, the fragility resistance of the produced sample was increased.Also, with an increase in the dough baking temperature of 140 to 160 degrees Celsius, the brightness of the produced sample was reduced. Then, the produced samples were compared with two commercial samples of "Pringles" and "Tordilla",which were prepared from maize flour,and chemical compounds, texture meter,amino acid content,colorimetry and organoleptic characteristics were studied. According to the results obtained at 5% level, the Tortilla from oat showed no significant difference in terms of the texture and color quality with the two commercial samples of Pringles and Tordilla as well as had higher essential amino acids, low fat and high quality protein content.Also,the tortilla and two commercial samples of  Pringles and Tordilla were evaluated by the assessors in terms of the indicators of crispiness, color, flavor and taste,which had a significant difference at the level of 5%, so that the highest score was for Pringles, Tortilla and Tordilla, respectively.

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In this paper, minimum-time low-thrust planar orbit transfer problem is solved by fuzzy optimal control. Trajectory dynamic restricting assumptions and using analytical averaging method, the governing equations of orbit transfer problem in its desired form with constant acceleration magnitude is achieved. Then, using Euler discretization method, the whole differential dynamic equations, performance function and transversality conditions are represented in a discrete form. Calling membership function concept of fuzzy environment, this algorithm transfers classical optimal control including performance index and trajectory transversality conditions associated with uncertanities to fuzzy environment. Thereafter, introducing slack variables all the inequalities change to equality conditions. Applying Bellman-Zadeh approach, optimal control problem turns to parameter optimization problem which then is solved by Lagrange multipliers technique. Finally, solving the set of nonlinear algebraic equations made by optimality necessary conditions simultaneously is achieved by nonlinear programming method. Numerical fuzzy optimal control results are validated with available analytical results which show the priorities of this method in orbit transfer trajectory optimization in presence of uncertainities. FOC approach is categorized into direct methods for solving optimal control problems, while it is far from their defects e.g. curse of dimensionality and burdensome computational load so that it applies fuzzy approach and expert knowledge to simply solve the problems.

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This paper investigates effect of coupling of satellite translational dynamics and rotational kinematic aiming to design of geosynchronous satellite formation flying at drift phase to the determined operational nominal position at the orbital window in the geosynchronous orbit. Firstly, dynamical and kinematical equations of satellite, and then, the interaction of translational and rotational motion at drifting to the final position at the target orbit by considering satellite as a rigid object have been studied. Despite of similar studies utilized simplifications such as circular assumption of target orbit or various linearization methods, presented analysis of this paper are based on the general form of nonlinear translational equations. According to acquired results of investigating the coupled dynamics at the drift phase to the determined position at the orbital window by considering different attitudinal situations, drift considerations and procedure in presents of other satellites at the orbital window have been presented. Position and attitude of satellite have been controlled by utilization of PD control law associated with the optimized gains based of PSO optimization algorithm aiming to minimizing control effort and fuel and consequently minimizing fuel consumption and increasing satellite operational life. Acquired results from simulations represent effectiveness of the proposed methodology.

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In the present paper the problem of designing a flying vehicle trajectory to avoid the collision with Terrain by limiting the flight range in a flight corridor influenced by the shape of the terrain has been investigated. In order to improve the traceability of the designed trajectory, considering the performance characteristics of the aircraft, the effect of two performance parameters including of the maximum rate of climb and the maximum increasing rate of the flight path angle, are considered in the solution algorithm. In this regard, the quantification of the system performance, has been implemented during the definition of different cost functions to minimize the operating time, control effort and vertical acceleration imposing on the aircraft. Mathematical modeling of the terrain which is considered as the route location of the threat, has been implemented using a power polynomial solution for smoothing. Finally, optimal control theory and nonlinear programming approach are utilized to solve the defined problem. The evaluation of case studies and numerical simulations confirmed the effectiveness of the proposed approach to solve the planning problem in flying maneuvers with low altitude requirements for follow and avoidance of direct and indirect environmental hazards.

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