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Bio-inspired nanostructured sensor for the detection of ultralow concentrations of explosives [electronic resource]
, Article Journal of Angewandte Chemie International Edition ; 29 May 2012, Volume 51, Issue 22, P.5334-5338 ; Simchi, A. (Abdolreza) ; Tamjid Shabestary, Elnaz ; Hartwig, Thomas ; Sharif University of Technology
Abstract
TNT: Silicon microcantilevers modified with a three-dimensional layer of vertical titanium dioxide nanotubes can be used in micromechanical sensors with optical signal detection to detect low levels of explosives such as 2,4,6-trinitrotoluene (TNT) in the gas phase, even in the presence of other volatile impurities such as n-heptane and ethanol
Constants of explosive limits
, Article Chemical Engineering Science ; Volume 173 , 2017 , Pages 384-389 ; 00092509 (ISSN) ; Jafari, M ; Farrokhpour, H ; Keshavarz, M. H ; Sharif University of Technology
Elsevier Ltd
2017
Abstract
This work defines density factor as the ratio of before ignition density to after ignition density of the ignition mixture. This work provides an estimation method for explosive limits of various fuels under room temperature and pressure by showing that for a large universe of fuels, constant adiabatic flame temperature and density factor are appropriate approximations at the lower explosive limit while only a constant density factor might be an appropriate approximation at the upper explosive limit. Thus the assumption of a constant adiabatic flame temperature can be used in calculating lower explosive limit while the assumption of a constant density factor can be used in approximating...
Investigation of Dynamic Response of Soil Exposed to Surface Explosion Pressure Waves
, M.Sc. Thesis Sharif University of Technology ; Farhanieh, Bijan (Supervisor)
Abstract
Explosion in soil medium have been a favourite topic for researchers From many years ago. however Most of researchs studied the impact of surface explosion on Perimeter environment (like mine explosion) and effect of the parameters like soil material and water content on pressure waves progressing inside of soil have been lees paid attention. In present work firstly we derive the data necessary for soil dynamic response computer modelling using different soil models from various resources. Then the impact of surface explosion will be investigated soil internally, using Ansys Autodyn numerical modelling. Results show that with an increase in soil water content, pressure wave peak overpressure...
A multivariable approach for estimation of vapor cloud explosion frequencies for independent congested spaces to be used in occupied building risk assessment
, Article Process Safety and Environmental Protection ; Volume 91, Issue 1-2 , 2013 , Pages 19-30 ; 09575820 (ISSN) ; Nourai, F ; Rashtchian, D ; Sharif University of Technology
2013
Abstract
API Recommended Practice 752 is one of the most referenced practices for evaluating vapor cloud explosion (VCE) impacts to site occupied buildings. This reference introduces generic VCE frequencies for different types of process units that are based on VCE incidents database. Although these reported VCE frequencies are not capable of illustrating all parameters that affect explosion likelihood, they are widely used in risk analysis studies and software packages. This paper delineates the structure of a more realistic method for estimation of local VCE frequencies for independent congested spaces or units as a function of process, site, and meteorological variables. Compared to traditional...
Improving accuracy of frequency estimation of major vapor cloud explosions for evaluating control room location through quantitative risk assessment
, Article Chemical Engineering Transactions ; Volume 24 , 2011 , Pages 1267-1272 ; 19749791 (ISSN) ; Nourai, F ; Rashtchian, D ; Sharif University of Technology
Italian Association of Chemical Engineering - AIDIC
2011
Abstract
Frequency estimation of vapor cloud explosions (VCE) are traditionally based on sparse VCE incidents data analysis while process conditions that generate VCE's have a wide spectrum giving VCE's with different strengths. The present paper is focused on developing a systematic methodology to estimate the frequency of VCEs based on process and plant conditions in order to find optimal location of a control room using quantitative risk assessment (QRA). In the presented approach, after classification of plant areas according to variables likely to generate different release conditions, a comprehensive release study is carried out to determine individual probable leakages. Consequently, only...
Risk assessment of vapor cloud explosions in a hydrogen production facility with consequence modeling
, Article Journal of Research in Health Sciences ; Volume 13, Issue 2 , 2013 , Pages 181-187 ; 16822765 (ISSN) ; Jafari, M. J ; Badri, N ; Sharif University of Technology
2013
Abstract
Background: New technologies using hazardous materials usually have certain risks. It is more serious when the technology is supposed to be applied in a large scale and become widely used by many people. The objective of this paper was to evaluate the risk of vapor cloud explosion in a hydrogen production process. Methods: Potential hazards were identified using the conventional hazard identification method (HAZID). The frequency of the proposed scenarios was estimated from statistical data and existing records. The PHAST professional software was applied for consequence modeling. Both individual and societal risks were evaluated. This cross-sectional study was conducted from June 2010 to...
Terahertz time domain spectroscopy for mixture detection: A quantitative study
, Article 4th International Conference on Millimeter-Wave and Terahertz Technologies, MMWaTT 2016, 20 December 2016 through 22 December 2016 ; 2017 , Pages 17-19 ; 21570965 (ISSN); 9781509054145 (ISBN) ; Yahyaei, B ; Kouhanestani, M. K ; Mousavi, M ; Darbani, M. R ; Majde, A. E ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2017
Abstract
Terahertz spectroscopy is a useful and an efficient method for detection of pure materials and also mixture compounds. In the present study the terahertz spectra of the α-lactose, high explosives RDX and also the binary mixture of mentioned materials has been obtained in the transition mode. The obtained spectra of the pure materials were in a very good agreement with literatures in the range of 0.1 to 1.5 terahertz. The spectra of mixture samples which show the specific fingerprint characters of each component, declare that terahertz spectroscopy can be used effectively for the detection of explosives and chemical compounds even in the mixture samples. © 2016 IEEE
Offshore accidents and effects on their performances
, Article Ocean '04 - MTS/IEEE Techno-Ocean '04: Bridges across the Oceans - Conference Proceedings, Kobe, 9 November 2004 through 12 November 2004 ; Volume 1 , 2004 , Pages 212-217 ; 0780386698 (ISBN) ; Hemati, P ; Sharif University of Technology
2004
Abstract
Marine accidents are some of the risk sources on human life at sea and also make the founded budget to be sank to the deep. In order to prevent these damages and losses, it is necessary to do a proper understanding of these accidents. Offshore systems as of the main parts of ocean structures and their accidents are considered here in this paper. From 1975 some data showing offshore accidents are captured in the Worldwide Offshore Accident Databank (WOAD), which are the main data bank to be used in this study. These data are about offshore damages and collapses due to Fires, Blowout, Anchor failure, Capsize, Explosion, etc. The main scope of the study is on fixed offshores, named jackets...
On the existence of canards in a nonlinear fluid system manifesting oscillatory behaviour
, Article International Journal of Non-Linear Mechanics ; Volume 98 , 2018 , Pages 58-63 ; 00207462 (ISSN) ; Lundberg, P ; Razvan, M. R ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
In an earlier study dealing with a nonlinear fluid oscillator governed by two autonomous ODEs, the solutions were found to display some aberrant characteristics adjacent to the boundaries of the oscillatory regime in parameter space. It was argued that this behaviour indicated the presence of canards. In the present study it is formally proved that this indeed is the case, and some numerical examples illustrating the phenomenon as well as its effects are presented. © 2017 Elsevier Ltd
Prediction of BLEVE mechanical energy by implementation of artificial neural network
, Article Journal of Loss Prevention in the Process Industries ; Volume 63 , January , 2020 ; Casal, J ; Planas, E ; Hemmatian, B ; Rashtchian, D ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
In the event of a BLEVE, the overpressure wave can cause important effects over a certain area. Several thermodynamic assumptions have been proposed as the basis for developing methodologies to predict both the mechanical energy associated to such a wave and the peak overpressure. According to a recent comparative analysis, methods based on real gas behavior and adiabatic irreversible expansion assumptions can give a good estimation of this energy. In this communication, the Artificial Neural Network (ANN) approach has been implemented to predict the BLEVE mechanical energy for the case of propane and butane. Temperature and vessel filling degree at failure have been considered as input...
Analytical Analysis and Numerical Simulation of Released Shock Waves on Buried Gas Pipelines
, M.Sc. Thesis Sharif University of Technology ; Farhanieh, Bijan (Supervisor)
Abstract
Underground gas pipelines are one of the vital parts of each country which surface blasts can break them down, make destructive explosions and threaten the safety of neighborhood structures and people. In this paper, to enhance the safety of these lines, response of buried 56 inch high pressure gas pipeline to a surface blast is numerically investigated. Beside the main aim, parametric studies on the effects of: i) explosive mass, ii) pipeline thickness, iii) burial depth and iv) concrete protective layer, on pipeline deformation are performed. To simulate the problem according to actual explosion events, geometries are modeled in real scales, pipeline properties are predicted with...
Synthesis of zero-valent iron nanoparticles via electrical wire explosion for efficient removal of heavy metals
, Article Clean - Soil, Air, Water ; Volume 45, Issue 3 , 2017 ; 18630650 (ISSN) ; Rabiee, H ; Seyed Shahabadi, S. M ; Borghei, S. M ; Sharif University of Technology
Abstract
In this paper, electrical wire explosion (EWE) was used as a simple, clean, in situ method to synthesise nano zero-valent iron (nZVI) particles in liquid mediums. The structural and physical properties of the synthesised nZVI particles were characterised by x-ray diffraction, Brunauer–Emmett–Teller analysis, field emission scanning electron microscopy and transmission electron microscopy. The synthesised spherical nanoparticles, at a specific size of 10–50 nm, possessed large surface areas of approximately 13.27 m2/g, reinforcing the significant advantages of EWE, that is, less aggregation and in situ production of nanoparticles with enhanced removal efficacy, for groundwater treatment....
A practical review study on shaped charge in the last two decades (2000–2020)
, Article International Journal of Protective Structures ; Volume 12, Issue 4 , 2021 , Pages 665-693 ; 20414196 (ISSN) ; Ramezani, A ; Nabakhteh, M. A ; Liaghat, G ; Sharif University of Technology
SAGE Publications Inc
2021
Abstract
Shaped charges are devices used for cutting or penetrating different aerial, on land, and underwater targets, based on the concentration of the explosion energy to the liner. The purpose of this study is to present a practical review of the studies related to shaped charges in the last twenty years (2000–2020). In this regard, these studies have been reviewed in two different categories for ordinary and advanced shaped charges. In the case of ordinary shaped charges, different aspects including shaped charges against different targets, different types of shaped charges (such as linear shaped charge and explosively formed penetrators), and theoretical advancements are presented. On the other...
A method for simulation of vapour cloud explosions based on computational fluid dynamics (CFD)
, Article Journal of Loss Prevention in the Process Industries ; Volume 24, Issue 5 , 2011 , Pages 638-647 ; 09504230 (ISSN) ; Rashtchian, D ; Abbasi, T ; Abbasi, S.A ; Sharif University of Technology
Abstract
The effectiveness of the application of CFD to vapour cloud explosion (VCE) modelling depends on the accuracy with which geometrical details of the obstacles likely to be encountered by the vapour cloud are represented and the correctness with which turbulence is predicted. This is because the severity of a VCE strongly depends on the types of obstacles encountered by the cloud undergoing combustion; the turbulence generated by the obstacles influences flame speed and feeds the process of explosion through enhanced mixing of fuel and oxidant. In this paper a CFD-based method is proposed on the basis of the author's finding that among the various models available for assessing turbulence, the...
Determination and identification of nitroaromatic explosives by a double-emitter sensor array
, Article Talanta ; Volume 201 , 2019 , Pages 230-236 ; 00399140 (ISSN) ; Hormozi Nezhad, M. R ; Sharif University of Technology
Elsevier B.V
2019
Abstract
Detection of nitroaromatic explosives is of strong concern because of human health, public safety, environment, and military issues. In this study, we present a ratiometric sensor array for detection and discrimination of widely-used nitroaromatics (i.e., 2,4,6-trinitrotoluene (TNT), 2,4,6-trinitrophenol (TNP), and 2,4-dinitrotoluene (DNT)). In the design of sensor elements (SE) we employ blue emissive carbon dots (BCDs) in combination with yellow (SE-A) and red (SE-B) emissive cadmium telluride quantum dots (CdTe QDs). The fluorescence intensity of BCDs, YQDs, and RQDs is quenched by TNT, DNT, and TNP in various degrees. Both TNT and TNP cause the quenching and spectral shift of BCDs (TNT...
Computational predictions for estimating the maximum deflection of reinforced concrete panels subjected to the blast load
, Article International Journal of Impact Engineering ; Volume 139 , 2020 ; Khalili, M. R ; Karami, B ; Rabczuk, T ; Shishegaran, A ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
We investigate the resistance of reinforced concrete panels (RCPs) due to explosive loading using nonlinear finite element analysis and surrogate models. Therefore, gene expression programming model (GEP), multiple linear regression (MLR), multiple Ln equation regression (MLnER), and their combination are used to predict the maximum deflection of RCPs. The maximum positive and negative errors, mean of absolute percentage error (MAPE), and statistical parameters such as the coefficient of determination, root mean square error (RMSE). Normalized square error (NMSE), and fractional bias are utilized to evaluate and compare the performance of the models. We also present a novel statistical table...
Consequences Analysis of Dust Explosions to Determine the Damage to Humans and Buildings
, M.Sc. Thesis Sharif University of Technology ; Rashtchian, Davood (Supervisor)
Abstract
Dust explosions are a serious hazard in many process industries and storage facilities. More than 70% of dusts processed in industry are combustible. This implies that majority of industrial plants that have dust processing equipment are susceptible to dust explosions. Dust explosions pose the most serious and widespread of explosion hazards in the process industry alongside vapour cloud explosions (VCE) and boiling liquid expanding vapour explosions (BLEVE). Dust explosions almost always lead to serious financial losses in terms of damage to facilities and down time. They also often cause serious injuries to personnel, and fatalities. In this project we presented a systematic algorithm in...
To Improve the Methods Using to Distinguish Congested Area in Process Plants by CFD
, M.Sc. Thesis Sharif University of Technology ; Rashtchian, Davoud (Supervisor)
Abstract
Among probable hazards in chemical industries: vapor cloud explosion (VCE) is one of the worst and most destructive ones. More than half of the major process inci¬dents, according to the statistics, are VCEs. VCE causes the most serious consequences; therefore, it attracts many attentions to itself. Accordingly, plenty of researches have been done for the purpose of protection against VCE effects. All efforts in this field can be categorized in two different main activities; firstly, prescribing safety distances between groups of hazardous equipment and vulnerable areas, secondly, using facilities which reinforce vulnerable areas against explosion blasts. Regardless to which category is...
Tolerating more hard errors in MLC PCMs using compression
, Article Proceedings of the 34th IEEE International Conference on Computer Design, ICCD 2016, 2 October 2016 through 5 October 2016 ; 2016 , Pages 304-311 ; 9781509051427 (ISBN) ; Sarbazi Azad, H ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2016
Abstract
Modern computer systems require fast, large and reliable memories to handle information explosion. With this goal in mind, not only deployment of main memories with new technologies are necessary, but also adopting innovative solutions for addressing newfound challenges must be considered as a priority. Recently, phase change memory (PCM) appeared as a preferred candidate for substituting DRAM. PCM with non-volatility, low static power consumption and storing multiple level cells (MLC) capability has opened a new way to the future of memories. Although PCM presents considerable potentials, its short lifetime is a critical concern. Worse still, adopting multiple bits per cell capability...
An investigation on the flow physics of bubble implosion using numerical techniques
, Article Ocean Engineering ; Volume 153 , 2018 , Pages 185-192 ; 00298018 (ISSN) ; Nasiri, M. M ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
In this paper, implosion of a micron-sized air bubble was studied numerically using OpenFoam software package. Then a parametric investigation on the flow physics of the problem was performed. The results show that as the initial pressure of the liquid increases, the pressure and the temperature inside the bubble increases such that in some cases, the temperature is as high as the one required for luminescence. Also, increasing the density and the temperature of the liquid solely, decreases the intensity of the collapse. © 2018