فصلنامه پدافند غیرعامل
سال نهم شماره 4 (پیاپی 36، زمستان 1397)

Urban water distribution network is subject to quantitative and qualitative threats. Quality threats include chemical and biological threats. The crisis in quality of urban water network directly affects human life in three areas of residence, work and activity, and can turn a technological crisis into a social and political one. The first step in the passive defense engineering strategy of urban water supply network is identification of areas at risk; distinguishing places with high risk profiles and selecting appropriate locations for installing water quality controllers. This study spans these five general criteria: damages to pipes, valves, breakers, directors; damages to tanks and water reservoir locations; people living and settled in the local housing facilities; people active at the local workplace, commutating citizens and traffic. It consists of 17 sub-criteria such as levels of service of areas and reservoirs, the distance from water transmission and distribution lines, proximity to contact tanks, refineries, tank floors, pumping stations and air tanks, population distribution and density, sensitive applications, regional work and activities and municipal services, green space, proximity to subway, highway network, railway network, and a network of ways, metro stations and metro lines. The AHP binary method of comparison carried out by 30 researchers using GIS spatial analysis with combination of sub criteria Tehran zone is divided into five categories: super critical, critical, short-term priority, medium term priority and without priority. Finally, as well as analyzing Tehran completely, three zones are shown to be most risky.

Monitoring the safety of huge structures and buildings such as bridges, dams, subways railways and airports as well as energy transmission pipelines and also monitoring places such as borders, security centers etcetera to reduce damages due to natural and non-natural disasters are subjects of particular interest in passive defense. In order to reduce the detriment of the events, various methods are applied such as: the use of accelerometers, radars, and vibration detection systems that operate with GPS to monitor the safety of bridges, tunnels and dams; the use of radars to monitor runways; the use of various wireless communication methods in rail lines, as well as methods to detect leakage of energy pipelines and etc. The safest and most innovative way to achieve this goal is the use of phase-sensitive distributed optical fiber sensor based on Rayleigh scattering. In these sensors, the Erbium amplifier and stimulated Raman and Brillouin scatterings are used to increase the sensing range. In the initial configurations of the sensor, the sensing range was about 6 km by utilizing Erbium amplifier. Maximum sensing range belongs to combination of Erbium and Brillouin amplifiers, which is about 300 kilometers. Along with the high sensing range, the accuracy and sensitivity of this category of sensors attract the attention of researchers and officials of various communities, especially for the purpose of passive defense measures.

One of the important issues in passive defense considerations is progressive collapse. Progressive collapse of the structure occurs when the major structural load carrying members are removed suddenly and the remaining structural elements are not capable of supporting the weight of the building and eventually result in collapse and failure of the structure. The main purpose of this investigation is assessment of the progressive collapse capacity of reinforced concrete special moment frame that is designed according to Iranian National Building Code (part 9). In this paper, two methods of analysis, nonlinear static analysis (pushdown analysis) and linear static analysis, are used for evaluating the progressive collapse capacity of special moment resisting frames with 3, 5 and 7 stories under two different scenarios. The Progressive collapse potential of SMRFs is evaluated based on the acceptance criteria of the last edition of UFC 4-023-03 document. The results show that the linear static analysis procedure has more conservative results compared to the pushdown analysis and the beam elements are also more vulnerable to progressive collapse than column elements.

After a nuclear explosion, we observe radiations like alpha, beta, gamma, and neutron rays, which emerge directly or indirectly from the explosion. Considering the importance of studying nuclear radiations and their range, these radiations are divided into initial and residual types. Apart from neutron and gamma rays, other radiations due to their physical nature are not significant in long-range studies. In this study, equivalent dose of the reference data’s initial radiation is calculated for benchmarking. On the basis of their power, initial neutron sources, secondary gamma sources caused by neutron interaction in the air, and gamma sources from fission products for the first minute after the explosion have been identified. By simulating the transport of these particles in the environment using Monte Carlo MCNPX Code, the equivalent doses in the tissue from 300 to 3800 meters have been calculated. Safe distance for exposure to 1KT weapon is equal to 1900 meters according to simulation results, and equal to 1800 meters based on the reference dose..

Camouflage is considered to be a passive defense principle. It is clear that, despite dramatic advances in the production of detectors and sensors, traditional camouflage technique does not have the necessary effectiveness to deal with these detectors, and development of detection and detection systems should be considered in the context of developing new solutions to countermeasure. One of these strategies is smart or adaptive camouflage. In this kind of camouflage, the goal is to react actively to environmental changes and to keep itself hidden from the eyes of the observer. In recent years, a number of researchers have made feasibility studies for such systems in research projects. These studies are not generally in the visible spectrum or have not led to production of a camouflaged system. In this research, design and simulation of an intelligent camouflage using electro-wetting technology have been developed. In this design, an array of optical micro-prisms consisting of a refractory liquid with a changeable shape is employed. By applying electric potential, small volumes of liquids are moved; thus, the angle of breakage of the prisms is controlled for different wavelengths. With objective of covering the surface of the targets, different fluids are used within the micro-prisms and behavior of different wavelengths is studied by writing the optical relations governing the prism output rays and a comparative camouflage pattern is presented.

Nowadays, electrical power systems which consist of generation, transmission, distribution, and control centers of electrical energy, are recognized as one of the strategic goals of modern warfare and threatened by various hazards, for which measures must be taken. Regarding the importance of power system in maintaining and sustaining communal activities, it is necessary to adopt adequate security measures to minimize threats and reduce vulnerabilities. In this context, passive defense can play an important role in the continuity of activities spanning from electric power generation up to consumption. In this paper, the influence of passive defense position upon increasing the security of power systems against sabotages and threats, has been addressed. To this end, first, the evaluation of destructive threats and related vulnerabilities in different parts of the network have been considered, then the effective strategies and ideas have been developed to decrease their vulnerability effects and increase the stability and security of network under critical and abnormal conditions. These strategies are based on the experiences of other countries and the research conducted in the field of passive defense, and can well cover most cyber and physical threats in the power grids.

Urban vulnerability is the quality and extent up to which the components and elements of a city are damaged in the event of an incident. The study of a city’s structures and the zoning of its vulnerability from the perspective of passive defense is a step towards the future prospects of a safe city. This paper studies the vulnerability challenge in city structures from a passive defense point of view and it is the expected modeling approach to identify these infrastructures. The statistical society of this paper is Dezful city, Khouzestan province; as the center of war provisions. This is a practical study from an objective point of view and an analytical descriptive study methodologically. It is based on space-modeling studies approach with10 formats of characteristics being identified and with the assistance of mixed analysis of AHPFUZZY-GIS, weighing distance maps has been designed and standardized. OVERAL FUZZY tools in ArcGIS application are used for spatial distribution and studying defense vulnerability. The results indicate that in analyzing indexes, police stations and warehouse indexes were the most significant ones in passive defense with weighs of 0.116 and 0.113. In Dezful's microsphere of urban structures, the following places were in danger of air strike attacks and had a completely vulnerable situation: 28/41 warehouse centers, 29/84 residents, 38/62 shopping centers, 32/35 business offices, 100 terminals and restrooms, 27/18 religious centers, 28/39 education centers and 38/33 the roads. According to these results it is clear that the situation of Dezful city from passive defense view is precisely not suitable for the times of air strikes and in case of any attacks the city will face major problems.

Passive defense is a kind of civil defense, which means reducing vulnerability during crisis. Passive defense is realized without military action and only through civilian, technical and managerial activities. Defensive planning is not a new issue since it has been on the agenda for a long time. In Iran, the Inactive Defense Organization was established in 1382 by the Supreme Leader of the Revolution. Defense and sustainability of design are two factors that form the architecture in passive defense. In this context, the architect must understand the defense from the point of view of the concept and content. Although the importance of linking the two domains of architecture and passive defense is clear, the big gap in this issue is the education debate. Unfortunately, the link between the two issues has been neglected in the academic field. Consideration of architectural issues in recent years has been studied by researchers in the field of passive defense. On the other hand, since 1388, the discussion of "Technical Criteria and Standards of Passive Defense" has been added as a draft to the twenty issues of national building regulations.  This script is the only valid designer document on this topic. Investigations show the lack of awareness of the passive defense graduates in relation to the design and architecture field. On the other hand, studying the titles and courses of architecture at different levels of education, and various perspectives and so on, indicate the lack of addressing the issue of passive defense in the field of architecture. So, the result is the graduation of designers and architects who have no knowledge of this important subject. The prospective of disregarding one of these two topics in the curriculum of the other, damages and challenges ahead, and providing solutions in the field of defining the topic of passive defense in architecture education and vice versa, are the issues discussed in this article.

Monitoring the safety of huge structures and buildings such as bridges, dams, subways railways and airports as well as energy transmission pipelines and also monitoring places such as borders, security centers etcetera to reduce damages due to natural and non-natural disasters are subjects of particular interest in passive defense. In order to reduce the detriment of the events, various methods are applied such as: the use of accelerometers, radars, and vibration detection systems that operate with GPS to monitor the safety of bridges, tunnels and dams; the use of radars to monitor runways; the use of various wireless communication methods in rail lines, as well as methods to detect leakage of energy pipelines and etc. The safest and most innovative way to achieve this goal is the use of phase-sensitive distributed optical fiber sensor based on Rayleigh scattering. In these sensors, the Erbium amplifier and stimulated Raman and Brillouin scatterings are used to increase the sensing range. In the initial configurations of the sensor, the sensing range was about 6 km by utilizing Erbium amplifier. Maximum sensing range belongs to combination of Erbium and Brillouin amplifiers, which is about 300 kilometers. Along with the high sensing range, the accuracy and sensitivity of this category of sensors attract the attention of researchers and officials of various communities, especially for the purpose of passive defense measures.