Search for: smoking
Total 41 records
Article Applied Mechanics and Materials ; Volume 232 , 2012 , Pages 620-624 ; 16609336 (ISSN) ; 9783037855140 (ISBN) ; Vakilimoghaddam, F ; Neishapouri, R ; Sharif University of Technology
Toxic gases resulted from fire events in subways stations are more dangerous than high temperature radiation from it. So, a well designed smoke exhaust system must be installed in subway station to control the smoke's propagation and discharging. Smoke extraction in subway station depends on the duct laid above the ceiling, so vents are situated in the same level of platform layer's ceiling. If subway station catches fire, smoke will cumulate in smoke reservoirs at the beginning and mechanical fan cannot exhaust any smoke in this process. In This paper, FDS 5.0 is used to simulate smoke's movement in a side platform of an actual subway station in case of a fire. Simulations are carried out...
Important Thermodynamic and Geometric Parameters of Smoke Management Systems for Stairwells: A Case Study, M.Sc. Thesis Sharif University of Technology ; Sani, Mahdi ; Moosavi, Ali
Smoke is the largest cause of fire related deaths. A smoke control system is an engineered system that modifies smoke movement for the protection of building occupants, firefighters and properties. Unfortunately, in case of fire, stairwells and elevators are frequently filled with smoke, preventing effective evacuation. Many smoke control systems use mechanical fans to control smoke by providing positive pressure at strategic locations. Pressure difference across a barrier can control smoke movement by preventing smoke on the low-pressure side of the barrier from migrating to the high-pressure side. Building designers use codes and rules of thumb to design their building against fire....
Numerical–analytical assessment of fire and ventilation interaction in longitudinally ventilated tunnels using jet fans, Article Heat Transfer Engineering ; Volume 38, Issue 5 , 2017 , Pages 523-537 ; 01457632 (ISSN) ; Afshin, H ; Farhanieh, B ; Sharif University of Technology
Taylor and Francis Ltd 2017
Longitudinal ventilation system is a frequent method of tunnel ventilation which is commonly implemented by use of jet fans. In most studies on longitudinal ventilation application, the effect of fire on its upstream is neglected and a constant-velocity flow is considered in the tunnel entrance. In this paper, fire consequences on ventilation system performance are investigated. It is noticed that airflow induced in tunnel declines as the fire intensifies. High reductions up to about 50% are observed and are attributed to two main phenomena; elevated downstream resistance and fire plume blockage. These effects are combined to form a parameter named fire pressure loss (FPL). An analytical...
M.Sc. Thesis Sharif University of Technology ; Farhanieh, Bijan
Suitable design of ventilation systems is one of the strategies to deal with phenomenon like fire in tunnels. For design a ventilation system first should recognize fire and effective parameters on it. So we need a good modeling of fire. Whereas the aim of this research is investigate the critical ventilation velocity, we only studying the effects of fire. Two effective parameter of fire is the rate of heat release and rate of smoke release, therefore with studying physics and nature of fire, obtain these parameters. After calculation of fire effects, we should investigate the effective parameters on critical ventilation velocity. The critical velocity is the air flow that helps prevent...
M.Sc. Thesis Sharif University of Technology ; Farhanieh, Bijan
Designing of an efficient emergency ventilation system is one of the main approaches to prevent the perilous fire in tunnel phenomenon. For this purpose, firstly, fire behavior and its heat release rate should be investigated. Knowing about temperature distribution and smoke movement is the second step. One of the most considerable factors in smoke control is critical velocity. It means the minimum velocity to prevent backlayering flow. If longitudinal ventilation velocity were less than this amount, smoke and hot gases originated from the fire can enter the upstream zone. This may cause lack of oxygen and decrease visibility for the passengers when they are escaping from the fire field. In...
Numerical Investigation of Fire Characteristics and Behavior in Confined Spaces; Near-Field and Far-Field Phenomena, Ph.D. Dissertation Sharif University of Technology ; Farhanieh, Bijan ; Afshin, Hossein
Safety against fire and its potential destructions is provided by detection, protection and ventilation methods. Knowledge on fire behavior such as ignition and propagation along with heat and smoke release is essential for implementing these methods. Having such deep information, the fire can be detected at the correct time and be controlled or suppressed, with its heat and smoke removed efficiently, so that rescue services will be enhanced and fatalities and damages will be reduced.Numerical simulation of fire requires deep understanding of multiple phenomena including turbulent flows, conductive, convective and radiative heat transfer, large buoyancy forces, chemical reactions and...
M.Sc. Thesis Sharif University of Technology ; Kalbasi, Hossein
Cosmology is a knowledge that deals with the matter of creation of the world, its current structure and its end. This scientific field that was a subject discussed by the scientific, philosophical and religious groups has nowadays taken the attention of many scientists and researchers. The philosophers of science, also, are not exemptions from theses groups and cosmology, as a topic common between philosophy and science, is one of the points that are under discussion in the field of philosophy of science. On the other hand, the religions, also, have noticed this issue. Koran that is the most complete divine book sent from God, has taken account of the creation and the Creator as the axis of...
Article Minimally Invasive Therapy and Allied Technologies ; Volume 25, Issue 3 , 2016 , Pages 121-128 ; 13645706 (ISSN) ; Mirbagheri, A ; Farahmand, F ; Sharif University of Technology
Taylor and Francis Ltd 2016
Background An automated instrument tracking procedure was designed and developed for autonomous control of a cameraman robot during laparoscopic surgery. Material and methods The procedure was based on an innovative marker-free segmentation algorithm for detecting the tip of the surgical instruments in laparoscopic images. A compound measure of Saturation and Value components of HSV color space was incorporated that was enhanced further using the Hue component and some essential characteristics of the instrument segment, e.g., crossing the image boundaries. The procedure was then integrated into the controlling system of the RoboLens cameraman robot, within a triple-thread parallel...
Patients' attitudes towards the role of dentists in tobacco cessation counselling after a brief and simple intervention [Attitudes des patients vis-à-vis du rôle des dentistes en matière de conseils dans le sevrage tabagique après une intervention simple et brève], Article Eastern Mediterranean Health Journal ; Vol. 20, issue. 2 , 2014 , p. 82-89 ; Homayoun, A ; Lando, H. A ; Haghpanah, F ; Khoshnevisan, M. H ; Sharif University of Technology
Dental professionals are in a unique position to promote smoking cessation among their patients. We evaluated the effects of a brief counselling intervention by a dentist on patients' attitude towards the role of dentists in tobacco cessation programmes. In a semi-experimental study in Tehran, Islamic Republic of Iran, 70 eligible smokers were selected and randomly assigned to intervention and control groups. The initial attitudes of the patients regarding tobacco cessation counselling services provided by the dentist were determined using a validated questionnaire. The intervention group received a brief chair-side counselling by a dentist based on the 5 A's approach, while no intervention...
Article Advanced Materials Research, 16 September 2011 through 18 September 2011 ; Volume 433-440 , Septembe , 2012 , Pages 983-991 ; 10226680 (ISSN) ; 9783037853191 (ISBN) ; Maddahin, R ; Afshin, H ; Farhanie, B ; Sharif University of Technology
Development of cities as well as population growth causes to development of public transportation especially subway lines. The high capacity besides the high speed in transportation makes them the popular transportation system. Fire is the one of the most important issues that may occur in subways. The difference in flame size, emissionheat, smoke and pollutants generation of subway fires attracts an especial attention of fire investigators. The emergency ventilation of subways in the case of fire should have the ability of discharging heat, smoke and pollutants from passenger escape route and preparing a safe place for a specific duration. The optimal performance of emergency ventilation...
M.Sc. Thesis Sharif University of Technology ; Farhanieh, Bijan
Fire spread in a road tunnel and its transmission from one vehicle to another was investigated numerically in this study. FDS was used as an open-source, free CFD software. Two boxes close to the car’s dimensions were modeled in a 40m long tunnel and fire transmission from one to another was considered. Ignition temperature was assigned to the second box’s surface as the condition for its ignition start and longitudinal ventilation was applied to the tunnel. At each case, ignition time of the second box was captured. Effects of ventilation velocity, HRR, distance, tunnel height and slope of the tunnel parameters were considered on the ignition time of the second box. Moreoveras a case study,...
M.Sc. Thesis Sharif University of Technology ; Moosavi, Ali ; Asghari, Mohsen
In this study pollution generated by a electronic cigarette in a bus is observed. Resultant smoke from these products consist of different components which may endanger health and one should make sure them amount in general transport vehicles like bus are in permissible limit. These components are initially in liquid shape and evaporate. Tracking liquid particles are done with the aim of Lagrangian approach. For this the geometry is generated at first. Then structured mesh was generated with ICEM CFD which is a powerful mesher. Different conditions of smoking source and bus doors were studies and results were compared.Change of pollutant concentrations is strictly depend on position of...
M.Sc. Thesis Sharif University of Technology ; Vosoughi Vahdat, Bijan
The fire event may cause danger to life and property. In general, most fire-detection devices are set on the wall or ceiling. . However, this method is not flexible enough to detect a fire occurrence, and this needs the use of many fire-detection devices in a building. Since it is not suitable, we use an active fire-detection device to detect a fire incident. In the past, smoke sensors were used for fire detection, but often the smoke sensors triggered a false alarm when someone smoked in the room. Therefore, multisensor fire-detection methods are one of the current important developments for fire- detection technology. We design a fire-detection module using an ionization smoke sensor...
Numerical Study of Various Parameters Affecting Ventilation and Fire- Induced Smoke Movement in Curved Road Tunnels, M.Sc. Thesis Sharif University of Technology ; Farhanieh, Bijan
When a fire breaks out in a tunnel, due to the enclosure of the interior of the road tunnels, hot and poison smoke quickly spreads in the tunnel. This phenomenon, in addition to destroy the tunnel structure, causes a lot of financial and human losses. In recent years, research into fire control has become more important with the occurrence of numerous accidents in road tunnels and fatalities. Longitudinal ventilation is still the main method for controlling smoke distribution in tunnels due to lower construction costs and acceptable efficiency. Numerous studies have been conducted to investigate the effect of different and effective parameters on fire control and smoke emissions in direct...
Investigation of the Fire-Induced Smoke Flow in the Complex Geometries Using The 3d Numerical Method and the Body-Fitted Curvilinear Coordinates, Ph.D. Dissertation Sharif University of Technology ; Farhanieh, Bijan ; Afshin, Hossein
With the process of achieving a higher state of social development and technological advances, the need for higher and more strict safety standards has been increased. In this regard, it is of great importance to have an accurate understanding of the fire phenomena and its consequences. Among the adverse effects of fire, a significant percentage of the fire fatalities is related to the fire-induced buoyant gases (smoke) flow which can lead to suffocation. Therefore, it is necessary to know the physics of the fire phenomena well. In fire investigation methods, the numerical study is an appropriate choice, because of the lower executive cost (relative to the experimental study) and the wider...
N-way partial least squares with variable importance in projection combined to GC×GC-TOFMS as a reliable tool for toxicity identification of fresh and weathered crude oils, Article Analytical and Bioanalytical Chemistry ; Volume 407, Issue 1 , January , 2015 , Pages 285-295 ; 16182642 (ISSN) ; Parastar, H ; Sharif University of Technology
Springer Verlag 2015
In this study, N-way partial least squares (NPLS) is proposed to correlate comprehensive two-dimensional gas chromatography-time of flight mass spectrometry (GC×GCTOFMS) data of different aromatic oil fractions (fresh and weathered) to their toxicity values. Before NPLS modeling, since drift and wander of baseline interfere with information of sought analytes in GC×GC-TOFMS data, a novel method called two-dimensional asymmetric least squares is thus developed for comprehensive correction of the baseline contributions in both chromatographic dimensions. The algorithmis termed comprehensive because it functions to correct the entire chromatogram in both dimensions and it preserves the...
Multivariate analytical figures of merit as a metric for evaluation of quantitative measurements using comprehensive two-dimensional gas chromatography–mass spectrometry, Article Journal of Chromatography A ; Volume 1466 , 2016 , Pages 155-165 ; 00219673 (ISSN) ; Parastar, H ; Sharif University of Technology
The present contribution is devoted to develop multivariate analytical figures of merit (AFOMs) as a new metric for evaluation of quantitative measurements using comprehensive two-dimensional gas chromatography–mass spectrometry (GC × GC–MS). In this regard, new definition of sensitivity (SEN) is extended to GC × GC–MS data and then, other multivariate AFOMs including analytical SEN (γ), selectivity (SEL) and limit of detection (LOD) are calculated. Also, two frequently used second- and third-order calibration algorithms of multivariate curve resolution-alternating least squares (MCR-ALS) as representative of multi-set methods and parallel factor analysis (PARAFAC) as representative of...
Article Journal of Porous Media ; Volume 12, Issue 4 , 2009 , Pages 313-326 ; 1091028X (ISSN) ; Sharif University of Technology
A new mathematical method is proposed to model the transport of polydisperse submicron aerosol particles in a heterogeneous porous media, and as an example, it is applied to study the transport of mainstream smoke aerosol particles in the cigarette tobacco column. The tobacco column is composed of randomly distributed pores and the aerosol particle transport is modeled utilizing a pore sub-model and taking into account aerosol particle coagulation and deposition. Copyright © 2009 Begell House, Inc
Numerical simulation to investigate the induced buoyant flow characteristics caused by intensive heat in complex curvilinear geometries, Article Heat Transfer - Asian Research ; Volume 48, Issue 3 , 2019 , Pages 835-853 ; 10992871 (ISSN) ; Farhanieh, B ; Afshin, H ; Sharif University of Technology
John Wiley and Sons Inc 2019
The buoyancy-induced turbulent flows in complex geometries with internal heat source have important application in enclosure fire dynamics, for example, smoke movement in the situation of fire in tunnels. The majority of computational works studying the fire-induced hot air movement in such cases use a Cartesian coordinate system. Hence, to simulate curved geometries, the Cartesian grid should be refined so that it comparatively matches the geometry. In the present work, a three-dimensional numerical method using nonorthogonal curvilinear coordinate system was developed. Numerical simulations were performed to study the flow structures and the heat transfer characteristics of fire-induced...
M.Sc. Thesis Sharif University of Technology ; Arhami, Mohammad
Tehran air quality is facing a real crisis. Reports of pertinent organizations show air quality is deteriorating in recent years and unhealthy days are increasing. As a result, study and planning in order to change this trend and moving toward improving air quality is a necessity. On the other hand, in order to make proper decisions and choosing effective approaches considering cost-effective attribute and legal, temporal and budget restrictions, selecting the right tool is essential. Air quality models are the tools which in a cost saving manner and reasonable time can provide the required results for researchers, decision makers and legislators. An applicable model correspondent with urban...