In this paper, a novel risk-based, two-objective (technical and economical) optimal reactive power dispatch method in a wind-integrated power system is proposed which is more consistent with operational criteria.  The technical objective includes the minimization of the new voltage instability risk index. The economical objective includes cost minimization of reactive power generation and active power loss. The proposed voltage instability risk employs a hybrid possibilistic (Delphi-Fuzzy)-probabilistic approach that takes into consideration the operator’s experience, the wind speed and demand forecast uncertainties when quantifying the risk index. The decision variables are the reactive power resources of the system. To solve the problem, the modified multi-objective particle swarm optimization algorithm with sine and cosine acceleration coefficients is utilized. The method is implemented on the modified IEEE 30-bus system. The proposed method is compared with those in the previously published literature, and the results confirm that the proposed risk index is better at estimating the voltage instability risk of the system, especially in cases with severe impact and low probability. In addition, according to the simulation results compared to typical security-based planning, the proposed risk-based planning may increase the security and economy of the system due to better utilization of system resources.

An 1D hydrodynamic model has been simulation and developed for gas hold-up and liquid circulation velocity prediction in air-lift reactors. model is based on momentum balance equations and has been adjusted to experimental data collected on a pilot plant reactor equipped with two types of gas distributors and using water as the liquid phase.The model equations described previously constitute a set of non-linear equations which are solved by an iterative procedure (v.b) (c plus). This model has also been combined with mass transfer and the kinetics of a chemical reaction to yield a complete model of the performance of a reactor.

A dry cooling process has been developed in which nominal cooling performance can be maintained even in high ambient temperature. Thermal energy is removed from cooling water and dissipated to the atmosphere by means of water filled heat pipes. The principle of an air cooler using heat pipe as the heat transfer device is presented in this paper. A heat transfer mathematical model is developed to simulate the properties of the air cooler. The model based on e-NTU (effectiveness- Number of Transfer Units) method can be used to predict the performance of heat pipe air cooler. To improve the performance of heat pipe air cooler, the Ce/Cc and number of rows should be increased.

Air Force played an incomparable role in the grounding of Saddam's war machine during the sacred defense era, especially in the first year of the war, according to the assigned missions. Therefore, the main goal of this research is to analyze the role of the air force in defeating the siege of Sosangard and to provide a model to improve the performance of this force in the future. This research, in terms of its purpose, is of the type of developmental research and in terms of its approach, it is the type of prospective qualitative research, which is based on the method of environmental monitoring and metacomposition, and based on the said method, an effort has been made to explain the role of Nahaja correctly. . The main source of data collection for this research is documents and documents, previous studies and topics presented in related meetings and conferences, especially the conference on Nahaja's role in defeating the siege of Sosangard, which was held in the University of Aviation Sciences and Technology in 2018. In order to check the validity and reliability of the obtained model, focus groups and Kappa index were used. Based on meta-composite methodology and by examining the obtained data, the concepts were extracted and coded in a multi-stage process and organized in the form of a model called the knowledge-based air defense model, whose dimensions include stopping and stabilizing hostile and enemy forces, supporting Other forces operating in the operation area are carrying out combat missions in the enemy's territory and strengthening the defense base of the country.

Due to its nature, the air force relies on advanced equipment and advanced technology, and without having an efficient technical-engineering system, it lacks the necessary efficiency and will easily lose its superiority in conflict scenes. The edge of knowledge and technology in the combat and operational power of the Air Force is manifested in the field of air technical-engineering power, and its operational efficiency is directly related to the number of ready-to-fly aircraft, the ability to maintain. Improving the production of flight missions, operational readiness of air fleet systems and equipment by spending minimum cost and using human, structural, technological, infrastructure and manufacturing of sensitive parts. Measuring technical-engineering power in the form of a specific model can clearly express the path of planning and targeting the development and improvement of the combat power of the Air Force. The main goal of this research is to achieve dimensions, components and measurable indicators of the technical-engineering power of the Air Power. The type of developmental-applied research and the research method is based on the nature of descriptive-analytical data with a mixed approach and their analysis in a mixed way and based on a sequential exploratory strategy using Smart p.l.s for the purpose of confirmatory factor analysis. Findings: The results of the research data analysis show that the technical-engineering capability of the military Air Power has 3 dimensions, 17 components and 61 indicators. The "maintenance and repair" dimension has 9 components, the "design and construction" dimension has 5 components, and the "standardization" dimension has 3 components

Introduction: This paper presents a portable device of Air Quality Monitoring System (AQMS) based on a sensor platform. The purpose of the study is to power awareness, warning indication, and minimal data storage capability. Materials and methods: AQMS is developed by embedded design methodology. The software part is based on the C programming language. AQMS device is made up of “, transmitter”,and “, receiver”,sections through the Zigbee wireless network. The objective is to collect concentrations of CO, NO2, CO2, humidity, and temperature to check air pollution for health awareness. A power-saving strategy is adopted in the "transmitter" of AQMS through a Demultiplexer circuit. To minimize the space complexity of storage and availability of long-term data, data encoding techniques are implemented. Results: By implementing switching activity on the sensors in AQMS, the active mode of sensing operations are controlled and a power saving of 18. 41% is achieved. Extending the duration of transmission operation increases data storage in the “, receiver”,unit. Hence, two encoding techniques are developed where real-time data are encoded in binary form: 2-bit encoding and 3-bit encoding. According to the results, 2-bit encoding saves 50% of storage space and 3-bit encoding saves 25%, compared to not utilizing any encoding strategy, sacrificing data accuracy by less than 5%. Conclusion: AQMS design is created with the implementations of low power consumption and low storage. Additionally, an alarming condition is set in AQMS for indicating the level of pollutants in the air to determine the risk level of exposure which is dangerous for human health.