فهرست مطالب ali alidoosti

Fire and explosion are the most prevalent accidents in chemical and process industries. Hence, identification of the hazard factors and the methods of controlling these two major accidents are very important in the process industries. In this paper, fire and explosion hazards of some process units at a combined cycle power plant have been estimated using the Dow fire and explosion index. The results of this study show that methane fueled turbine has the highest value of Dow index which is 321, turbine unit with gas oil and gas oil storage site have the Dow index values of 147.5 and 35.5 respectively. The loss control credit factor for methane fueled turbine unit was 0.36 and the Actual Maximum Probable Property Damage was 4.12 US million dollars. Maximum Probable Days Outage is estimated to be 50 days and finally, the loss due to unit pauses is calculated to be 3.03 US million dollars. In addition, the findings of the current study show that the gas oil storage unit suffers the highest amount of loss due to business interruption. The findings of the present study can be used for the improvement of inherent safety and can also be applied to estimate the losses due to fire and explosion.

In this article, a uniform framework is presented that has the capability to be used in multi hazard risk evaluation, specifically seismic hazards and hazards related to wise threats. In this stream, first, common equations for seismic risk evaluation are completed in a more general pattern. The main novelty of this phase was providing the direct connection between every two parameters without any intervening third parameter. To show the performance of such re-derived equations, they are implemented on a sample case selected from petrochemical industry, where a vessel mounted on skirt is falling on a pipe rack. It is illustrated that traditional equations cannot predict complex risks like overturning of one equipment on another one. In spite of that, new proposed equations can simply include such irregular happenings and hence would provide more accurate risk estimates. In the next step, the state and wiseness parameters are added to the revised equations, introduced above, which adds the capability of applying these equations against wise threats. The wiseness parameters implemented in these equations are the knowledge of the owner about the asset, the knowledge of the owner about threats, the capability of owner to process the available knowledge and take preventive actions, the knowledge of wise threat about target asset, the knowledge of wise threat about attacking capabilities and at the wise threat ability to process the available knowledge and take offensive actions. In this part, again, the high flexibility and performance of new proposed equations is shown for different states of owner-attacker knowledge through several examples. These examples cover blind attack, wise attack, wise attacker against owner with restricted knowledge, wise attacker against owner with restricted processing and acting capabilities and, at last, attacker with restricted knowledge against wise owner. In the final step, the applicability of proposed equations for cases with dynamic variable states and dynamic owner-attacker knowledge levels are illustrated in an example. It is expressed that how dynamic parameters can be included, through revising probability distribution functions, in the proposed framework. It should be confirmed that the presented equations can be reduced to the traditional form which is common in current seismic risk evaluation practice. Also it should be mentioned that the above equations just form the basic framework in risk evaluation and in order to implement them in real cases, each term would need to be expanded to several new parts. Besides, the required probability distribution equations should be provided for every specific problem distinctly.

Buried pipelines used to distribute water, gas, oil, and etc. are considered as one of the vital arteries. The experiences of the past wars have confirmed that the invading country focuses on bombing and destroying vital centers, and that gas pipelines can be a source of serious personal and financial losses as an important transmission arteries during war in the event of damage The vulnerability of buried urban gas pipelines to explosion was determined and the methods for reducing the vulnerability of pipelines were investigated. To this end, the three-dimensional model of the soil-pipe system in ABAQUS software was used to study the effect of factors affecting the pipe behavior, including pipe diameters, diameter to pipe thickness, internal friction angle of soil, soil type, amount of explosives, depth of buried, the distance of explosion site to the pipe burial site, has been investigated on the pipe deformation capacity according to the ALA regulation. The soil was modeled using Solid three elements and shell element. For parametric studies, analyses were performed by the finite element method using ABAQUS software 6.10.1. Studies were conducted for 4 and 12 inch diameter, diameter/thickness ratio of 26, 21 and 35, burial depth of 1, 2, 3 and 4 meters, the explosive charge of 15, 30, 45, 60 and 200 kg TNT and for soil material, hard, soft and clay sands. The results showed that proper burial depth had the most effect in reducing the vulnerability of pipelines against explosive threats. By increasing the pipe thickness and increasing the diameter and applying soft soil around the pipe, a better behavior of the pipe was observed during the explosion To reduce the vulnerability of gas pipelines against explosive threats, the use of buried pipelines has a greater effect on reducing damage due to explosion compared to other parameters, and it is recommended to use this method to increase the resilience of highly important gas pipelines.

The general concern about supplying food is one of the important issues before an earthquake happens. This research aims to present a conceptual model for “humanitarian supply chain practices to supply food before an earthquake” and prioritizing its practices. This research is applied in nature and it is descriptive regarding the tools and instruments of data collection. After reviewing the related literature and interviewing some experts, 7 criteria and 19 sub-criteria were identified. Then the questionnaire was distributed among the related managers, experts, and academics and 281 questionnaires were completed and gathered. This measuring model was tested according to Structuring Equation Modeling. Furthermore, Fuzzy AHP was used to weight the importance of each practice and its dimensions. Our findings showed that “Monitoring”, “Education”, and “Readiness for logistics and distribution” are the most important dimensions of our conceptual model. So, we used one sample t-test to measure the performance of each practice. Finally, importance-performance matrix was used for prioritizing the practices. We hope that our results will be a good guidance for managers and decision makers of humanitarian supply chain for better understanding of food supplying practices before an earthquake.

Earthquake is a natural disaster that provides casualties, loss of financial and environmental every year. Iran due to its location on the belt of seismicity is extremely vulnerable to earthquakes. Also a lot of facilities before design criteria of seismic have been made and unfortunately quality of construction in the country was not suitable. Therefore, with respect to suspicious behavior of networks in possible earthquakes, seismic vulnerability assessment of critical infrastructure is great importance.
In the proposed model initially seismic hazard analysis of based on 2 attenuation relationship for the country done, which according to the uncertainties involved in earthquake (magnitude of earthquake, focal depth and location of epicenter of the earthquake), this operation is selected at random each time and after each hazard analysis, the output of ground shaking (Peak ground acceleration, Peak ground velocity and peak ground displacement) is calculated. If the zone have been the landslide susceptibility or liquefaction susceptibility, then need the output of the hazard analysis of ground failure resulting from the permanent displacement of liquefaction and landslide are entered for each features in to the proposed model. Then the seismic vulnerability functions that for each two hazards of ground shaking and ground failure was put for every lifeline in the model database is used. Finally, according to the available functions, loss estimation of every network would do. All of these steps are for once analysis. So based on the Monte Carlo simulation, All of these operations on 10 thousand times to consider all of the uncertainties and failure modes are repeated then averaging available outputs in the database, so that all failure modes be considered. Therefore, due to the large data attribute and geometry, while the high spatial analyzes on large data as well as mathematical equations for repeated operations, attempted to coding in Visual Studio with programming language C # using .Net Framework and Arc Engine libraries and based on spatial information systems designed and developed that could estimate damage probability of slight, moderate, extensive and complete for each lifeline separately in the form of maps and tables for each feature. In this paper, in order to get a better view this research, models was implemented and analyzed for the city of Neyshabour.

After the 9. 11 disaster inNew York، we have become more aware of the catastrophic threats in our communities. While the 9. 11 disaster was not directed toward the oil industry، chemical facilities may pose an attractive target for terrorism، with the purpose of using the effective physical and chemical properties to cause mass casualties، property damage، and economic or environmental impacts. This study focuses on assessing the security risk of the Man-made Disasters for critical assets in the oil industry. This research modifies conventional risk assessment methods for including terrorism and sabotage scenarios by Joshan model. The objective of this risk assessment is to identify security hazards، threats and vulnerabilities facing each target asset، and to find the adequate countermeasures to protect the public، workers، national interest، environment، and companies. This model includes five steps: asset characterization، threat assessment، vulnerability analysis، risk assessment and new countermeasures. Therefore، Joshan-Pro is introduced in order to security vulnerability assessment for critical asset protection.