طراحی

Ribbon parachutes are used for speed reduction and stabilization of high-speed payloads and aircrafts. In the present research, a ribbon parachute is designed for air-dropped payload recovery and simulated by using multiple engineering softwares to analyze aerodynamic loads and structural stresses. The canopy is made from nylon 66; its deployed diameter is equal to 1.2 m and consists of 8 gores. The aerodynamic loads, pressure, and structural stress distributions are computed in four different free stream velocities of 40, 80, 100, and 120 (m/s). Based on these results, the most critical point on canopy structure is designated. The results show that the location where the suspension lines are attached to the fabric has the highest amount of tension and displacement due to the aerodynamic loads.

Amongst the most important issues ensuring the safety and security of citizens and reducing the crisis in cities, are practical and multi-purpose plans in which passive defense considerations and principles are observed. These plans reduce the severity and extent of damage and loss due to hazards. Forest parks are the type of urban recreation areas that with proper planning, provide space for recreation, cultural and educational activities, to meet the psychological needs and peace of society in normal conditions, and offer suitable space for temporary housing, warehousing, relief operations, and sustainable security in the time of emergencies and crisis. In this research, an attempt has been made to design forest parks in accordance with the objectives of passive defense, using plants and natural features and artificial elements, with the possibility of housing in emergency conditions. The purpose of this design is to utilize the urban green space and use the relief and housing plan in emergency situations to increase the ability to use green space in times of crisis and use places for safe keeping and storage of food and rescue equipment. This research is applied research in terms of descriptive-analytical nature and library studies, field observation and objective have been used to collect information. After conducting studies and investigating the factors effective in location assignment, and also implementing the colonial competitive algorithm in Matlab software, the Pasdaran district is identified as the most suitable location and marked on the google map software. Applying the results of the research and taking into account the general and defensive requirements, a park is designed using AUTOCAD software.

Power systems have been traditionally designed and operated based on the main principles of reliability, i.e. security and adequacy. These principles can properly deal with identified failures in the power infrastructure components. However, recently occurred high impact low-probability (HILP) threats have raised the concerns about the classical reliability-oriented view. As a critical infrastructure, power systems are more and more expected to be resilient to HILPs. So, the related governmental organizations put their endeavors to enhance the resiliency of these networks against HILPs. For this purpose, there is a great need to identify different threats and evaluate their impacts. The investigation of different threats, identification of different ways to enhance the resiliency and finally introducing smart grid concept as an efficient way to increase the resiliency of the distribution networks are reviewed in this paper.

Today Threats to urban areas are known as a common phenomenon in all natural and man-made disasters. So offering plans to decrease their effects on cities seems to be necessary. Urban planning as a practical science, through Involvement in various aspects cities, can provide reducing the vulnerability of cities in natural and man-made Threats. In this study Kermanshah city is used as a case study, which strategically is known as one of the most important border zones. Afterwards a questionnaire, SPSS software and chi-2 test were used and then the truth of the questionnaire was checked. Finally, different methods of planning processes were analyzed, to reduce vulnerability study area in the threat.

Increasingly developing of the human civilization throughout the world will effect on human life mode in future. The sphere population is increasing and the nations are searching for the best life standards, and the earth must supply more food, energy and mineral reservoirs to support the increasingly crowd. Underground spaces play a basis role in safe keeping the national assets and currently, it is considered as the most attractive and safest option to use. The advantages of such spaces are high security, low keeping costs, low energy-consuming, high degree of control and prevention from biological impacts. according to these characteristics, these spaces are more effective than other spaces. Therefore, using specially the passive defense approaches for many of these spaces can make them very safe and they will be the powerful and secure cases in dangerous and threatening conditions.In this study, at first the overall identification and assessment of underground spaces was represented and then it has addressed the principles of architecture design underground spaces with the presentation of applied patterns in some sectors such as, designing entrances and external view, Locating and organizing spaces, Interior design, Lighting system, safety and security in different condition. Architectural design of every underground space due to its situation like slope of the surface, the surface being trapped underground space and high density construction on the ground, and the type of operation, such as business, sports, military and ..., is done specifically; which considering design goals and the presented patterns help to better exploit it and it will be fewer problems faced by farmers from the functional point of view.

What has been done in this study is preparing and editing procedures, implications and considerations to design NBC field hospitals both mobile and fixed ones from passive defense perspective. The design and construction studies of these medical centers play an important role in defensive support of a country's health and treatment domains in critical situations and a large number of these treatment centers are considered as sensitive and important centers. Studying the developmental trend of such centers during the Eight-Year Holy War and other wars shows that these centers are directly and indirectly targeted by natural and man-made threats, both conventional and unconventional ones. Therefore, editing procedures and considerations for architectural design and site location of NBC field hospitals from passive defense perspective is indispensable and is the aim of this study. The present study which is of applied and scientific type, makes use of field library studies and questionnaires to gather data and the data analysis method employs a descriptive analytical method. Here is the general trend of this study: after the study design which consists of definition and objectives of the subject, subject history, questions and the domain of the subject, the type and the study methods are expressed. Then using the questionnaires, the determined criteria for the design of a safe field hospital are described. Afterwards, the results of the questionnaires will be utilized to achieve the desired design. Subsequently, an analysis is conducted and the general considerations of a field hospital will be discussed. Then the objectives of passive defense regarding an NBC field hospital will also be described and the history of establishing different field hospitals during the Holy War will follow and after discussing the principles of architecture from passive defense perspective in designing safe locations, the elements of safe field hospitals against unconventional threats will also be explained and in the end, applied samples of a safe field hospital will be presented. We hope that this study can provide vast case and subject approaches for subsequent future studies.