This paper presents an intelligent power management strategy for hybrid wind/ fuel cell/ energy storage power generation system. The dynamic models of wind turbine, fuel cell and energy storage have been used for simulation of hybrid power system. In order to design power flow control strategy, a fuzzy logic control has been implemented to manage the power between power sources. The optimal operation of the hybrid power system is a main goal of designing power management strategy. The hybrid power system is simulated in MATLAB/ SIMIULINK environment and different operating conditions have been considered to evaluate the response of power management strategy.

In this research, a hybrid renewable system based on the use of solar and oceanic thermal energy to produce power and hydrogen by using a flat plate solar collector was investigated from a thermodynamic and economic point of view. The objective functions investigated in this research were exergy efficiency and cost rate. Collector mass flow rate, collector area, turbine inlet temperature, and solar radiation intensity were considered as four decision variables, and the effect of these parameters on system performance and system exergy loss was investigated. The optimization of objective functions was done by the Nelder-Mead method. From single-objective optimization, it was concluded that the best system exergy efficiency rate is 7.31% and the system cost rate is 27.48 $/hour in the optimal state. From the sensitivity analysis, it was concluded that increasing the parameters of the collector area, solar radiation intensity, and turbine inlet temperature had a positive effect on the system performance, and increasing the mass flow rate parameter of the solar collector had a negative effect on the system performance. Also, from the analysis of the exergy loss of the system, it was concluded that the increase in the intensity of solar radiation, the area of the collector, and the mass flow rate of the collector increase the overall exergy loss of the system, but the increase in the inlet temperature to the turbine decreases the exergy loss of the system.

Background: The purpose of this study is to determine the incidence of electrolyte and ABG abnormalities in infants with (HPS) and also we evaluate other parameters of the study.‎Materials and Methods: This descriptive study covers 161 infants with (HPS) hospitalized in children Medical center of Tehran university underwent surgical repair from march 1996 to march 2002 . ‎Results & Conclusion: The results indicated that Hypokalemic metabolic alkalosis had occurred in 40% of patients. ‎The sex ratio was 3/1 =M/F and the most time of presentation was between 15t and 5st week and the most presenting sign was vomiting. Clinical icter happened to be found in 15% of patients. The incidence of accompanying anomalies was 9% and olive sign was palpable in 40%. ‎The best way for evaluating and diagnosis was sonography. ‎The mean period to begin postoperative feeding was 30 hours" no complication related to option was reported after operation.

This paper deals with the performance investigation and control of a combined wind-microturbine generation system at off-grid and stand-alone applications. As the novelty, in this paper, the wind turbine does not always work at the MPPT mode, and depending on the available wind power and load demand, two operation modes for the wind turbine are defined: power control mode (MPPT mode) and voltage control mode. At the conditions that the available wind power is less than the load demand, the wind turbine operates at the MPPT mode and microtubule provides the rest of the load power. Once the available wind power goes beyond the load demand, the microturbine can not absorb the additional power, and wind turbine works at load following mode. In this mode, the wind turbine power is less than the available wind power and is identical to the load demand, and the microturbine power is negligible. At the end, by performing simulations at the Matlab-Simulink environment, performance of the study system at different operating conditions is investigated.

This paper aims to examine a combined heating, power, and hydrogen system production using biogas energy. Biogas steam and dry reforming method are designed based on equilibrium data with the EES program. The results show that biogas has two principal roles for combustion and reforming processes simultaneously. The heating energy produced from biogas causes the reforming of biogas and improves the system efficiency by 74%. The maximum exergy efficiency and hydrogen production are obtained at 58.34% and 0.11-0.83 kg/s, respectively. The results also show that the combustion chamber has the highest exergy destruction by about 51% when the amount of electric power plant is considered between 5 to 40 MW. A parametric study for optimizing hydrogen production analyzes the key parameters. The optimal scenarios are when CO2/CH4=0.50-0.66, H2O/CH4=2-3.6, and the reforming temperature is 965-1036K. The conversion of methane and carbon dioxide shows the environmental effect of decreasing greenhouse gases. At 965K or higher, methane and carbon dioxide conversion rates reach 97% and 86%, respectively. This paper aims to develop a novel methodology for identifying thermodynamic cycle conditions and reforming processes only by use of biogas as the source of energy.y y y y y y y y y y