فصلنامه پدافند غیرعامل
سال چهاردهم شماره 1 (پیاپی 53، بهار 1402)

Increasing the resistance and resistance of structures against the forces caused by various accidents, has always been considered by design engineers. In recent decades, the creation of defensive conditions in structures of great importance and very high impact against loads is an integral part of structural designs. In this laboratory research, a mixing plan was made of ordinary concrete containing Portland cement type 2 with a grade of 500 kg/m3</sup>. Impact strength test of falling weight in concrete was performed on concrete samples at 90-day curing age at 21, 300 and 600 °C. In order to further evaluate and validate the results, scanning electron microscopy (SEM) and X-ray diffraction (XRD) spectroscopy tests were performed on concrete samples at 90 days of processing age. The results of the tests of this research were evaluated and compared with the results of the research of others. Heat application in concrete samples had a significant effect on the results. In this regard, in the drop weight test, the absorbed energy increased from 269.7214 (at 21 °C) to 41.5956 (at 600 °C) and decreased It had 76.92 percent and the flexibility index increased from 2.3 (at 21 degrees Celsius) to 2.5 (at 600 °C) and improved by 69.8 percent. At the end of this study, the results of SEM and XRD analysis at 21 °C and high temperature, while coordinating with each other, overlapped with the results of other tests in this article.

Every year, many irreparable accidents occur in process systems such as oil, gas and petrochemicals due to their acute operating conditions and the large volume of flammable and explosive materials they contain. Process industries often deal with hazardous chemicals and operating units under high temperature and pressure conditions such as transmission lines, condensing facilities and reactors. One of the most important units of these industries are storage tanks, which are located in all stages of process industries. According to studies and studies in this field, there are several solutions for the privacy of tanks, but they have not been studied from the perspective of passive defense. Therefore, we considered it necessary to conduct a special study on creating a relatively safe space for these storage tanks. The purpose of this study is to investigate the components of passive defense in the design of storage tanks for hazardous chemical industries. The method of this research is developmental-applied in terms of type and descriptive-analytical-survey in terms of research method, in which it answers through questions, interviews and data collection and factor analysis (PCA). In terms of how to collect data, it is a field method that includes collecting initial data by methods such as observation, questionnaire, interview and review of documents of constructed projects. Factor analysis with SPSS with high degree of certainty is a way to reduce the dimensions of a problem with many variables in statistical modeling, thus 4 areas of 40 main components, which show the highest variability in the model (without using the main variables) Give, was determined. According to experts, these four areas were named "passive defense area", "crisis management area", "process area" and "health, safety and environmental safety area". These factors can be introduced as hidden variables. In the next step to identify and rank the key factors of success (CSF), variables were ranked in each area. Dangerous chemical industries have been stored in storage tanks.

In this paper, the cruise missile’s DSMAC positioning system is simulated based on correlation. Then, in order to create a disturbance and analyze the effects of each disturbance in the performance of this positioning system, items such as changing image resolution, brightness, ambient coverage, viewing angle and other random variables such as artificial changes (smoke) were used. In order to determine the area of defense operation against this system, considering the missile inertial navigation system error and the possibility of circular error (CEP), it has been proved that the DSMAC location is within a radius of three to five kilometers from the target. By analyzing the obtained results, it has been shown that the areas with more black pixels, such as forest areas, are undesirable areas for DSMAC. In addition, by using jamming in the cruise missile altimeter system, the accuracy of the missile altimeter process can be reduced so that the image positioning system is completely disrupted. Also, the larger the size and area of the total artificial changes (smoke) and the color of the changes, in proportion to the background of the image, the disruption and defense against the DSMAC system will be possible. Finally, by providing operational scenarios, the defense against the cruise missile DSMAC positioning system has been realized.

Planning for the transportation infrastructure of border areas is one of the new fields in planning and policy making for the development of the country. In addition to moving millions of passengers, The Country's transportation network also moves factory products, agricultural products, fuel, chemicals, etc and creating a short interruption in its services in a critical situation where The country is facing shortages, can bring irreparable effects to the various activities of The country. Experiences from The wars of the last half century show that the Infrastructures of the border areas have always been under various threats. therefore, the protection of transportation infrastructure is very important because of the important role they play in human life. The Main goal of this research is to identify the weak points of these infrastructures in the border areas and provide solutions to reduce these vulnerabilities. In this article, using FEMA's risk assessment method, first the assets of the border provinces' transportation area are identified and screened, then the vulnerabilities are identified and evaluated based on the threats based on the statistics, and The risk of each asset is calculated and at the end, solutions are provided to reduce the risk in the transportation infrastructure of the border provinces.

This paper examines the security risks and challenges associated with energy sources for ships, including increasing fuel prices, tightening international pollution laws, and limited space and fuel on board. With the rise of modern naval warfare and technological advances, energy production for vessels has become a strategic priority. This study focuses on identifying threats in electricity generation for ships and investigates the reliability and availability of various energy production systems. Using a Markov model, the study compares different energy production systems by considering their advantages and disadvantages, influential factors, and level of reliability and availability. Results show that the use of solar energy in combination with diesel generators has the highest reliability (0.988) and availability (0.997) compared to other production sources. The study demonstrates that solar energy can be used to meet a portion of the ship's power consumption needs, reduce maintenance and repair costs, extend the life of generators, increase the duration of navigation, ensure continuity of energy supply, and improve passive defense in the field of electrical energy for marine vessels.

Due to the devastating effects of the Industrial Revolution and technological advances in recent decades, the preservation of capital and natural resources, as well as the reduction of adverse effects of mechanization in all its dimensions, have received worldwide attention and led human society to the significant concept of "sustainability" in all areas, especially ecological, social, and economic macro aspects. However, the term sustainability is not limited to the three mentioned areas only in normal conditions. As human beings have lived in threat since the beginning of creation, maintaining this sustainability in times of crisis is also of particular importance. For this goal, the concept of passive defense is considered, mainly in special fields such as architecture. Because the architectural space should be to respond to function appropriately and create desirable spatial qualities in different time and location situations, it can also help strengthen the defense as an intermediary means. With this explanation, the main purpose of the present research is to achieve a pattern based on the spatial organization in the architectural design process that aims to strengthen the commonalities and moderate the divergences of sustainability strategies, with acceptable reliability, in both secure and crisis conditions to optimize the design. It should be noted that the research is of the applied kind in terms of purpose and descriptive-analytical in terms of method. In other words, it is a qualitative content analysis that collects qualitative data from the research literature through a documentary study and infers significant components forming the main variables of the problem using descriptive coding followed by a survey of experts through the Delphi technique. Finally, analyses have been concluded through logical reasoning. Based on the results, it should be acknowledged that some factors by having influences on sustainability in secure and crisis conditions, strengthen each other and some factors weaken. Therefore, according to the type of usage of buildings and other significant contextual conditions, decisions should be made appropriately and solutions should be adopted in the spatial organization that leads to strengthening the convergence of agreed factors and moderating the confrontation of divergent factors.

The main purpose of this paper is to develop a design guide for locating underground urban shelters based on the criteria that are used in the passive defense. Today, the passive defense alongside the defense is one of the security systems for residential settlements of interest to urban planners; underground shelters are one of the main examples of the passive defense among them. Underground shelters once more emphasize that sub-surface structures such as subway lines and spaces such as underground shops and shopping centers are defined as urban elements in the urban spatial structure.The multiple uses of metro stations, both in times of peace and in times of crisis, have increased their functional importance. Metro stations will be used as shelters in war, but in terrorist attacks, they will be considered as a place to kill people. In order to preserve human capital and reduce the vulnerability of people and places as much as possible, it is necessary to examine these cases and consider the effective role of passive defense in showing the subway station as a safe haven in crisis situations and creating a safe place. Therefore, by applying non-active defense in the metro station, the crisis can be better controlled to some extent and the metro station can be considered as a strategic and busy place to establish security.

considerations of passive defense in urban planning and design may help to reduce the damage of cities and the loss of life and property, and at the same time increase the resistance threshold of citizens in attack situations and facilitate the management of city crisis. This is an applied research by quantitative method. In this study, to achieve the goal of determining the degree of dependence of urban areas, four criteria of physical, cyber, geographical and logical interaction have been used and the score of each asset according to its degree of dependence on other assets has been calculated and defined as a score for the asset. The statistical population of the study includes all strategic centers of sabzevar. The purpose of this study is to investigate the impact of strategic centers in sabzevar on each other and show the spatial distribution of level of risk in this city. In the field of cyber interaction, the assets of telecommunication infrastructure company and combined cycle power plant were the most dependent on the relevant information flow. Also, in the field of logical interaction, the assets related to the political and health and treatment infrastructure of Sabzevar city had the highest logical interaction rate with an interaction rate of 6. </strong>

Concrete is one of the common materials in strategic structures, and because of it, fabric concrete (CC), which is also called fabric reinforced concrete (TCR), is considered one of the latest technologies in the world. According to the general applications of fabric concrete, the need to investigate and evaluate it in the field of military and defense becomes clear, and for this purpose, in this research, fabric concrete targets with dimensions of 120 mm x 120 mm and thickness of 10 mm are subjected to the penetration of steel projectiles with flat, hemispherical and conical noses. have been tested and the velocity of the ballistic limit of a specific fabric concrete sample and the maximum diameter of destruction of the front and back surfaces of the sample have been measured. The failure mechanism of fabric concrete samples has emerged in the form of brittle and fragmentation type failure, which have shown a relatively good performance against the penetration of projectiles, so that the area and diameter of destruction on the front surface of the samples was very small and sometimes as much as the diameter of the projectile. On the back surface of the samples, the amount of destruction is also acceptable and with the increase of the impact speed, the amount of destruction has also increased linearly, and the ballistic limit speed for steel projectiles with flat, hemispherical and cone noses is 124, 110 and 100 m/s, respectively. It is stated that it indicates the easy penetration of projectiles with a conical nose and the difficult penetration of projectiles with a flat nose. </em>

Health-medical land uses are among the uses that are of great importance for human health in the event of an accident, so in critical situations, there is a possibility of their dysfunction because the vulnerability of this use to accidents is very high, in this regard, optimal location with optimal use The passive defense approach is of great importance. The main purpose of this study is to locate the hospital using the passive defense approach in Urmia. The present study is descriptive-analytical in nature and applied in terms of purpose. The basic information and maps of this article have been collected in the form of libraries and fields from reliable scientific and official sources. Indicators used in this study include indicators of distance from educational centers, residential centers, commercial centers, green spaces, religious centers, existing hospitals, accesses, open and public areas, administrative centers, fire stations, workshop and industrial centers, and sports centers. Data analysis was performed through weighting, application compatibility, and fuzzy logic method. The study area in this study is the city of Urmia, located in the province of West Azerbaijan. The results of this study indicate that a significant part of the city of Urmia is outside the coverage radius of existing hospitals, so there is a need for a principled location of new hospitals. Also, Region 1 has the most and most appropriate, and Region 4 has the least area for hospital use.

Buckling Restrained Brace (BRB) has the ability to wear and absorb energy well. The aim of this study was to obtain the results of dynamic behavior of metal structures and seismic system with CBF braces and compare them with the results of steel structures equipped with BRB bracing with two different cross sections due to near field earthquake and better building control. Considering that our country is located in an earthquake-prone region, it is inevitable to take into account the considerations related to near-fault earthquakes in the design of the standard earthquake spectrum. In this paper, two 5 and 10 level steel structures are modeled in Etabs software. This software was selected for the initial design of structural elements and then using Perform-3D software, their seismic behavior in near field earthquakes was evaluated with two braces BRB and CBF. The result of this study shows that structures with non-buckling braces have high energy absorption and absorption and have the same behavior in pressure and tension, which causes maximum and more base shear as well as better performance than Structures with CBF bracing. They also control the movement of the building due to its high stiffness. Finally, if the metal cross-sectional area of the BRB braces is higher, the performance of the structure and displacement will be better controlled. Finally, energy consumption by this brace, as mentioned above, responds to equal traction and pressure, like a damper.