A common method for Controlling a group of parallel converters in decentralized Control strategy structure in an island microgrid, the use is the droop-down characteristics of frequency ω-P and voltage E-Q. However, the problem with using this method is that the reactive power is not properly distributed (in proportion to the capacity of the micronutrients) between the micronutrients, which may lead to overload in the converters. Microgrids may also suffer from dynamic stability problems such as power fluctuations, which can be increased by switching between active and reactive power Control. To avoid this problem, the X / R ratio of transmission lines is an important parameter that should be carefully considered in the design of micronutrient Controllers. By linearizing and simplifying conditions, the Control system conversion function model becomes a single input-single output system, which is efficient enough to show the relationship between Control parameters such as slope of droop characteristics and derivative sentences, virtual impedance, and voltage Controllers. Using this model, stability conditions for different parameters are analyzed. Also, to improve power distribution stability, common droop strategies are modified by adjusting the slope as well as adding nonlinear sentence sections. This approach reduces the coupling between active and reactive power Control and reduces the dependence of power distribution on grid parameters such as the X / R ratio. To evaluate the reliability of the proposed model, the simulation results in a sample island microgrid in MATLAB software are presented.

This study was performed to evaluate the effect of adding a mixture of peppermint, thyme and rosemary essential oils (EOs) in a ratio of (3:1:2), respectively, to the diet, on growth performance, rumen and blood parameters of fattening lambs. Twenty-one Mehraban lambs with an average weight of 29.80 kg were randomly allocated to one of three diets: 1) Control, 2) base diet+1.25ml of EOs and 3) base diet+2.5ml of EOs. Daily weight gain was greater in the groups receiving the EOs than in the Control, although this increase was mainly due to the interactions of treatment over time. Feed consumption and feed conversion ratio compared to the Control did not altered. The total concentrations of VFAs and acetate in the groups receiving EOs decreased (P<0.05), while the concentration of propionate increased (P<0.05) at the level of 2.5ml of EOs and isovalerate increased (P<0.05) in both levels of EOs compared to the Control. Total population of protozoa, rumen pH and ammonia nitrogen concentration were not affected by treatments. Glucose concentration increased at high level of EOs (P<0.05). Concentrations of urea, cholesterol, triglycerides, creatinine, total protein and albumin did not altered. The number of red blood cells, hemoglobin, hematocrit, number and percentage of white cells including lymphocytes and eosinophils were not affected by treatments but the percentage of monocytes decreased (P<0.05) at low level of the EOs. The results of this experiment showed that the addition of mixture of EOs to the diet did not have a significant effect on performance parameters and immune system of lambs, although it reduced the total concentration of VFA and acetate and increased the concentration of propionate.

This study is aimed to examine the relation between internal Control disclosures level and earning quality. Accounting earning is one of the most important elements of financial reporting and since internal Control disclosures improve financial reporting quality, it can improve earning quality too. To measure internal Control disclosures level, this study, using leng and ding (2011) and Kwame Agyei-Mensah (2016), examines each firm annual report in order to calculate internal Control disclosures Index. Earning quality is measured using discretionary accruals absolute value. This study begins in 2013 because "The Internal Controls Rule" for the firms listed in Tehran Stock Exchange and Farabourse firms was approved by Securities and Exchange Organization in 2012. The Statistical population is firms listed in Tehran Stock Exchange during the period 2013 to 2016 and the sample consists of 424 year-firm observations. Results show that there is a positive (direct) relation between internal Control disclosures level and earning quality.

One of the issues of reliable performance in the power grid is the existence of electromechanical oscillations between interconnected generators. The number of generators participating in each electromechanical oscillation mode and the frequency oscillation depends on the structure and function of the power grid. In this paper, to improve the transient nature of the network and damping electromechanical fluctuations, a decentralized robust adaptive Control method based on dynamic programming has been used to design a stabilizing power system and a complementary static var compensator (SVC) Controller. By applying a single line to ground fault in the network, the robustness of the designed Control systems is demonstrated. Also, the simulation results of the method used in this paper are compared with Controllers whose parameters are adjusted using the PSO algorithm. The simulation results show the superiority of the decentralized robust adaptive Control method based on dynamic programming for the stabilizing design of the power system and the complementary SVC Controller. The performance of the Control method is tested using the IEEE 16-machine, 68-bus, 5-area is verified with time domain simulation.

Background and Aims: Lasers with different characteristics have been used to stimulate orthodontic tooth movement. Considering the contradictory findings in this regard, this study was designed to assess the effect of low level laser therapy (LLLT) on the rate of orthodontic tooth movement.Materials and Methods: In this randomized clinical trial study, 12 patients (4 boys and 8 girls; average age: 16.9±3.4) with extracted upper first premolars and required canine retraction into extraction site were included. While in both sides canines were retracted by NiTi coil spring, one side was exposed to GaAlAs laser (890 nm). LLLT was done (on the buccal and palatal mucosa by slow movement of probe) at the beginning of the first month. Impression and cast fabrication performed at the beginning of retraction, one and two months later. The amount of retraction on the cast was measured with the aid of a reference plaque fabricated on the rogae using a digital caliper. Data were analyzed using paired sample T-test and one-sample Kolmogorov-Simirnov test.Results: There was no significant difference in the amounts of canine movement between laser exposed and Control sides (P>0.05).Conclusion: The energy dose of laser used in this study (72 J per each tooth) was not appropriate for increasing dental movement.