This study was conducted during summer and winter of 2018- 2019 in the agricultural research field of Shahid Chamran University. Experimental design was split- plot based on RCBD with three replications. The main plot was the type of agricultural system in three levels including conventional (Conv), organic (Org) and sustainable (Sust) (integrated between Conv and Org) and sup- plot was the type of pre- cultivated crop in sequence with wheat including cultivation of mung bean (M- W), corn (C- W), sesame (S- W) and fallow (F- W). Yield quantity (yield and its component) and quality (grain protein), an estimate of photosynthesis matter transfer index of wheat and soil organic carbon (SOC) after one double-cropping were measured. The result showed that the highest (545.04 g/m2) and the lowest (409.28 g/m2) seed yields were obtained in Conv and Org respectively. In contract, with the changing type of system from Conv to Org, grain protein was increased significantly (from 8.3 to 9.6 %). In addition, the highest (535.47 g/m2) yield of wheat was obtained from M- W double cropping. On the other hands the highest remobilization and current photosynthesis matter were obtained in the organic agricultural system with M- W and conventional with M- W double cropping. The situation of SOC showed that the highest (33.18 mg/g) SOC was obtained in the organic agricultural system with C- W double cropping. The reason for improving SOC in the organic and sustainable agricultural system was application of organic matter (compost and vermicompost) and crop residue management. Totally, from the crop ecology point of view, sustainable agricultural method with a sequence of M- W was the most desirable system.

In this paper, we study multilevel multi-photon resonances in a strongly driven four-level quantum system, where one level is periodically swept through other levels with constant energy separation E and 2E. Near the multi-photon resonance conditions, we find qualitatively different behavior for the number of even or odd photons. We explain this phenomenon in terms of families of interfering trajectories of the multilevel system. For beginning our detailed analysis based on a perturbative treatment in terms of the small parameters that characterize the strong driving limit, we introduce the strong-dephasing regime that is modeled by Gaussian white-noise fluctuations on each of the unperturbed energy levels. Within this model we calculate the rates of inter-level transitions, working up to fourth order in the couplings. Finally, we connect our results to the experiments in which current through spin-blockaded double quantum dots was measured in the presence of strong ac driving. The setup can be relevant for a variety of solid state and atomic or molecular systems. In particular, it provides a clear mechanism to explain recent puzzling experimental observations in strongly driven double quantum dots.

A New Static Var Genera tor (SVG), using cascaded full-bridge inverters (FBI) with binary output levels and the parallel connections of two cascaded inverters by means of current sharing reactor in each phases is introduced. The new M-level inverter, where M is 2n+2 - 3, consists of only 2n single-phase full bridges for each phase. The proposed technique not only increases the current capacity of proposed SVG but also decreases the output harmonic contents. Also, it can be connected directly to the distribution system without a transformer. Simulation results, based on the PSCAD/EMTDC, a high performance electromagnetic transient simulation program, are used to illustrate the flexibility of control action and also the performance of the proposed SVG in a power system environment.

Integration of the PV into the electrical grid needs power electronic interface. This power electronic interface should have some key features and should come up with grid codes. One of the important criteria is the quality and harmonic contents of the current being injected to the grid. High-order harmonics of the grid current should be very limited (lower than 0.3% of the fundamental current). Beside the topology of the power electronic interface, the output filter also affects the quality of the grid current. In this paper, a 5-level inverter is presented for grid integration of PV systems along with its output LCL filter design. Analytical calculation of losses for the 5-level inverter and the output LCL filter is presented. It is also compared to the H-bridge inverter in terms of output voltage and current harmonics, and the overall losses. Second-order generalized integral phase locked loop is used to synchronize the system with the grid voltage and the proportional resonant (PR) with harmonic compensation control method is used to control the output current. The proposed system has been simulated in the PSCAD/EMTDC environment to verify its operation and control.

In this paper, we study a new kind of multiphoton resonances in a strongly driven six-level quantum system, where one of its levels is coupled individually with the other two levels that have the constant energy separation E. Near the multiphoton resonance condition, a different behavior for the number of even or odd photons was found qualitatively, which could be explained by considering two certain interfering trajectories and computing the interference phase of system. In the regime of strong dephasing, we calculated the rates of interlevel transitions, showing that multilevel Landau-Zener (LZ) interferences between first and third order processes could lead to resonances with characteristics differing markedly from those of familiar two-level resonances that first arose at the fourth order in the couplings of the energy levels. The rates displayed resonant features at the number of integer photons. Finally, we could explicitly connect our model to the experiments, showing that it captured all relevant features of the experimental data. This paper can be relevant for a variety of solid state and atomic or molecular systems. In particular, it provides a clear mechanism to explain the puzzling experimental observations in strongly driven double quantum dots.

Hierarchical hub location problems locate hub facilities on the  rst and second of three levels under the best economic conditions. The present study introduced a novel hierarchical hub set covering problem with capacity constraints. This study showed the signi cance of  xed charge costs for locating facilities, assigning hub links and designing a productivity network. Set covering was imposed to use the minimum number of variables and coverage constraints. The proposed model employs mixed integer programming to locate facilities and establish links between nodes according to the travel time between an origin-destination pair within a given time bound. The demand nodes are fairly covered at each service level and no demand node remains unanswered. The formulation was linearized by replacing the non-linear constraints with less intuitive linear structures. The resulting linear model was solved using GAMS and tested on the Australian Post dataset and the Iranian Airport dataset.

In this research, a single-phase multilevel inverter with a reduced number of switches and driver circuits is introduced for analysis in photovoltaic systems. The proposed multilevel inverter consists of two parts, basic circuit, and H-bridge, which are responsible for generating voltage levels and symmetry of voltage levels (positive and negative), respectively. The proposed basic circuit in this paper consists of six unidirectional switches and three input sources and doesn’ t use any capacitors or diodes, which reduces the volume and complexity of the control system. In this paper, the seven-level proposed structure is simulated in the MATLAB/Simulink software and the utilized modulation to generate the output voltage levels is level shifted pulse width modulation. Moreover, photovoltaic systems are exploited to supply the proposed inverter’ s input sources, which work with perturb and observe algorithm at the maximum power point. In the simulation section, the voltage, current, power waveforms of the photovoltaic system, and the voltage of the proposed inverter input sources are demonstrated, and the voltage and current waveforms of the inverter for different conditions such as radiation and modulation index change are given. Finally, to show the merits and features of the proposed topology, the inverter is compared with some recent symmetrical structures in terms of the number of components and the rated voltage of the switches.