Search results for: fire incident

Authors: Fabienne Samyn, Pauline Tranchard, Sophie Duquesne, Emilie Goncalves, Bruno Estebe, Serge Boubigot

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Stringent fire safety regulations are enforced in the aeronautical industry due to the consequences that potential fire event on an aircraft might imply. This is so much true that the fire issue is considered right from the design of the aircraft structure. Due to the incorporation of an increasing amount of polymer matrix composites in replacement of more conventional materials like metals, the nature of the fire risks is changing. The choice of materials used is consequently of prime importance as well as the evaluation of its resistance to fire. The fire testing is mostly done using the so-called certification tests according to standards such as the ISO2685:1998(E). The latter describes a protocol to evaluate the fire resistance of structures located in fire zone (ability to withstand fire for 5min). The test consists in exposing an at least 300x300mm² sample to an 1100°C propane flame with a calibrated heat flux of 116kW/m². This type of test is time-consuming, expensive and gives access to limited information in terms of fire behavior of the materials (pass or fail test). Consequently, it can barely be used for material development purposes. In this context, the laboratory UMET in collaboration with industrial partners has developed a horizontal and a vertical small-scale instrumented fire benches for the characterization of the fire behavior of composites. The benches using smaller samples (no more than 150x150mm²) enables to cut downs costs and hence to increase sampling throughput. However, the main added value of our benches is the instrumentation used to collect useful information to understand the behavior of the materials. Indeed, measurements of the sample backside temperature are performed using IR camera in both configurations. In addition, for the vertical set up, a complete characterization of the degradation process, can be achieved via mass loss measurements and quantification of the gasses released during the tests. These benches have been used to characterize and study the fire behavior of aeronautical carbon/epoxy composites. The horizontal set up has been used in particular to study the performances and durability of protective intumescent coating on 2mm thick 2D laminates. The efficiency of this approach has been validated, and the optimized coating thickness has been determined as well as the performances after aging. Reductions of the performances after aging were attributed to the migration of some of the coating additives. The vertical set up has enabled to investigate the degradation process of composites under fire. An isotropic and a unidirectional 4mm thick laminates have been characterized using the bench and post-fire analyses. The mass loss measurements and the gas phase analyses of both composites do not present significant differences unlike the temperature profiles in the thickness of the samples. The differences have been attributed to differences of thermal conductivity as well as delamination that is much more pronounced for the isotropic composite (observed on the IR-images). This has been confirmed by X-ray microtomography. The developed benches have proven to be valuable tools to develop fire safe composites.

Keywords: aeronautical carbon/epoxy composite, durability, intumescent coating, small-scale ‘ISO 2685 like’ fire resistance test, X-ray microtomography

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Authors: Bagus Hanindhito, Fariz Azmi Pratama, Ulfah Nadiya

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Nowadays, digital system including, but not limited to, computer and internet have penetrated the education system widely. Critical information such as students’ academic records is stored in a server off- or on-campus. Although several countermeasures have been taken to protect the vital resources from outsider attack, the defense from insiders threat is not getting serious attention. At the end of 2017, a security incident that involved academic information system in one of the most respected universities in Indonesia affected not only the reputation of the institution and its academia but also academic integrity in Indonesia. In this paper, we will explain our efforts in investigating this security incident where we have implemented a novel rapid evidence remote acquisition method in high-availability server and storage system thus our data collection efforts do not disrupt the academic information system and can be conducted remotely minutes after incident report has been received. The acquired evidence is analyzed during digital forensic by constructing the model of the system in an isolated environment which allows multiple investigators to work together. In the end, the suspect is identified as a student (insider), and the investigation result is used by prosecutors to charge the suspect as an academic crime.

Keywords: academic information system, academic crime, digital forensic, high-availability server and storage, rapid evidence remote acquisition, security incident

Procedia PDF Downloads 127

Authors: Hosia T. Pule, Julius T. Tjelele, Michelle J. Tedder, Dawood Hattas

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Acceptability of plant material to herbivores is influenced by, among other factors; nutrients, plant secondary metabolites and growth stage of the plants. However, the effect of these factors on Seriphium plumosum L. acceptability to livestock is still not clearly understood, despite its importance in managing its encroachment in grassland communities. The study used 2 x 2 x 2 factorial analysis of variance to investigate the effect of season (wet and dry), fire, slope position (top and bottom) and their interaction on Seriphium plumosum chemistry. We tested the hypothesis that S. plumosum chemistry varies temporally, spatially and pre- and post-fire treatment. Seriphium plumosum edible material was collected during the wet and dry season from burned and unburned areas on both top and bottom slopes before being analysed for protein (CP) content, neutral detergent fibre (NDF), total phenolics (TP) and condensed tannins (CT). Season had a significant effect on S. plumosum protein content, neutral detergent fibre, total phenolics and condensed tannins. Fire had a significant effect on CP. Interaction of season x fire had a significant effect on NDF and CP (p < 0.05). Seriphium plumosum in the wet season (6.69% ± 0.20 (SE)) had significantly higher CP than in the dry season (5.22% ± 0.13). NDF was significantly higher (58.01% ± 0.41) in the dry season than in the wet season (53.17% ± 0.34), while TP were significantly higher in the dry season (14.44 mg/gDw ± 1.03) than in the wet season (11.08 mg/gDw ± 1.07). CT in the wet season were significantly higher (1.56 mg/gDw ± 0.13) than in the dry season (1 mg/gDw ± 0.03). CP was significantly higher in burned (6. 31 % ± 0.22) than in unburned S. plumosum edible material (5.60 % ± 0.15). Seriphium plumosum CP was significantly higher in wet season x burned (7.34 % ± 0.31) than wet season x unburned (6.08 % ± 0.20) material and dry season x burned (5.34 % ± 0.18) and unburned (5.09 % ± 0.18) material were similar. NDF was similar in dry season x burned (58.31% ± 0.54) and dry season x unburned (57.69 % ± 0.62) material and significantly higher than similar wet season x burned (52.43% ± 0.45) and wet season x post-unburned (53.88% ± 0.47) material. This study suggests integrating fire, browsers, and supplements as encroacher S. plumosum control agents, especially in the wet season, following fire due to high S. plumosum CP content.

Keywords: acceptability, chemistry, edible material, encroachment, phenolics, tannins

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Authors: Akram Mahdaviparsa, Tamera McCuen, Vahideh Karimimansoob

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Fire service is responsible for protecting life, assets, and natural resources from fire and other hazardous incidents. Search and rescue in unfamiliar buildings is a vital part of firefighters’ responsibilities. Providing firefighters with precise building information in an easy-to-understand format is a potential solution for mitigating the negative consequences of fire hazards. The negative effect of insufficient knowledge about a building’s indoor environment impedes firefighters’ capabilities and leads to lost property. A data rich building information modeling (BIM) is a potentially useful source in three-dimensional (3D) visualization and data/information storage for fire emergency response. Therefore, this research’s purpose is prioritizing the required information for firefighters from the most important information to the least important. A survey was carried out with firefighters working in the Norman Fire Department to obtain the importance of each building information item. The results show that “the location of exit doors, windows, corridors, elevators, and stairs”, “material of building elements”, and “building data” are the three most important information specified by firefighters. The results also implied that the 2D model of architectural, structural and way finding is more understandable in comparison with the 3D model, while the 3D model of MEP system could convey more information than the 2D model. Furthermore, color in visualization can help firefighters to understand the building information easier and quicker. Sufficient internal consistency of all responses was proven through developing the Pearson Correlation Matrix and obtaining Cronbach’s alpha of 0.916. Therefore, the results of this study are reliable and could be applied to the population.

Keywords: BIM, building fire response, ranking, visualization

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Authors: Matthew J. I. Woolley, Gemma J. M. Read, Paul M. Salmon, Natassia Goode

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The significance of high consequence, workplace failures within construction continues to resonate with a combined average of 12 fatal incidents occurring daily throughout Australia, the United Kingdom, and the United States. Within the Australian construction domain, more than 35 serious, compensable injury incidents are reported daily. These alarming figures, in conjunction with the continued occurrence of fatal and serious, occupational injury incidents globally suggest existing approaches to incident analysis may not be achieving required injury prevention outcomes. One reason may be that, incident analysis methods used in construction have not kept pace with advances in the field of safety science and are not uncovering the full range system-wide contributory factors that are required to achieve optimal levels of construction safety performance. Another reason underpinning this global issue may also be the absence of information surrounding the construction operating and project delivery system. For example, it is not clear who shares the responsibility for construction safety in different contexts. To respond to this issue, to the author’s best knowledge, a first of its kind, control structure model of the construction industry is presented and then used to analyse a fatal construction incident. The model was developed by applying and extending the Systems Theoretic and Incident Model and Process method to hierarchically represent the actors, constraints, feedback mechanisms, and relationships that are involved in managing construction safety performance. The Causal Analysis based on Systems Theory (CAST) method was then used to identify the control and feedback failures involved in the fatal incident. The conclusions from the Coronial investigation into the event are compared with the findings stemming from the CAST analysis. The CAST analysis highlighted additional issues across the construction system that were not identified in the coroner’s recommendations, suggested there is a potential benefit in applying a systems theory approach to incident analysis in construction. The findings demonstrate the utility applying systems theory-based methods to the analysis of construction incidents. Specifically, this study shows the utility of the construction control structure and the potential benefits for project leaders, construction entities, regulators, and construction clients in controlling construction performance.

Keywords: construction project management, construction performance, incident analysis, systems thinking

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Authors: Inigo Beckett

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In forensic investigations, it is often the case that the most potentially useful recorded evidence derives from coincidental imagery, recorded immediately before or during an incident, and that during the incident (e.g. a ‘failure’ or fire event), the evidence is changed or destroyed. To an image analysis expert involved in photogrammetric analysis for Civil or Criminal Proceedings, traditional computer vision methods involving calibrated cameras is often not appropriate because image metadata cannot be relied upon. This paper presents an approach for resolving this problem, considering in particular and by way of a case study, the angle of a simple ladder shown in a photograph. The UK Health and Safety Executive (HSE) guidance document published in 2014 (INDG455) advises that a leaning ladder should be erected at 75 degrees to the horizontal axis. Personal injury cases can arise in the construction industry because a ladder is too steep or too shallow. Ad-hoc photographs of such ladders in their incident position provide a basis for analysis of their angle. This paper presents a direct approach for ascertaining the position of the camera and the angle of the ladder simultaneously from the photograph(s) by way of a workflow that encompasses a novel application of projective geometry and matrix analysis. Mathematical analysis shows that for a given pixel ratio of directly measured collinear points (i.e. features that lie on the same line segment) from the 2D digital photograph with respect to a given viewing point, we can constrain the 3D camera position to a surface of a sphere in the scene. Depending on what we know about the ladder, we can enforce another independent constraint on the possible camera positions which enables us to constrain the possible positions even further. Experiments were conducted using synthetic and real-world data. The synthetic data modeled a vertical plane with a ladder on a horizontally flat plane resting against a vertical wall. The real-world data was captured using an Apple iPhone 13 Pro and 3D laser scan survey data whereby a ladder was placed in a known location and angle to the vertical axis. For each case, we calculated camera positions and the ladder angles using this method and cross-compared them against their respective ‘true’ values.

Keywords: image analysis, projective geometry, homography, photogrammetry, ladders, Forensics, Mathematical modeling, planar geometry, matrix analysis, collinear, cameras, photographs

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Authors: Ulrica Pettersson

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Collection of information on incidents is regularly done through pre-printed incident report forms. These tend to be incomplete and frequently lack essential information. ne consequence is that reports with inadequate information, that do not fulfil analysts’ requirements, are transferred into the analysis process. To improve an incident reporting form, theory in design science, witness psychology and interview and questionnaire research has been used. Previously three experiments have been conducted to evaluate the form and shown significant improved results. The form has proved to capture knowledge, regardless of the incidents’ character or context. The aim in this paper is to describe how design science, in more detail a design hierarchy can be used to construct a collection form for improvements in safety science.

Keywords: data collection, design science, incident reports, safety science

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Authors: Yogendra K. Karna, Lauren T. Bennett

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Fire-tolerant eucalypt forests are one of the major forest ecosystems of south-eastern Australia and thought to be highly resistant to frequent high severity wildfires. However, the impact of different severity wildfires on the canopy structure of fire-tolerant forest type is under-studied, and there are significant knowledge gaps in relation to the assessment of tree and stand level canopy structural dynamics and recovery after fire. Assessment of canopy structure is a complex task involving accurate measurements of the horizontal and vertical arrangement of the canopy in space and time. This study examined the utility of multitemporal, small-footprint lidar data to describe the changes in the horizontal and vertical canopy structure of fire-tolerant eucalypt forests seven years after wildfire of different severities from the tree to stand level. Extensive ground measurements were carried out in four severity classes to describe and validate canopy cover and height metrics as they change after wildfire. Several metrics such as crown height and width, crown base height and clumpiness of crown were assessed at tree and stand level using several individual tree top detection and measurement algorithm. Persistent effects of high severity fire 8 years after both on tree crowns and stand canopy were observed. High severity fire increased the crown depth but decreased the crown projective cover leading to more open canopy.

Keywords: canopy gaps, canopy structure, crown architecture, crown projective cover, multi-temporal lidar, wildfire severity

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Authors: Robert Pečenko, Karin Tomažič, Igor Planinc, Sabina Huč, Tomaž Hozjan

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Timber is favourable structural material due to high strength to weight ratio, recycling possibilities, and green credentials. Despite being flammable material, it has relatively high fire resistance. Everyday engineering practice around the word is based on an outdated design of timber structures considering standard fire exposure, while modern principles of performance-based design enable use of advanced non-standard fire curves. In Europe, standard for fire design of timber structures EN 1995-1-2 (Eurocode 5) gives two methods, reduced material properties method and reduced cross-section method. In the latter, fire resistance of structural elements depends on the effective cross-section that is a residual cross-section of uncharred timber reduced additionally by so called zero strength layer. In case of standard fire exposure, Eurocode 5 gives a fixed value of zero strength layer, i.e. 7 mm, while for non-standard parametric fires no additional comments or recommendations for zero strength layer are given. Thus designers often implement adopted 7 mm rule also for parametric fire exposure. Since the latest scientific evidence suggests that proposed value of zero strength layer can be on unsafe side for standard fire exposure, its use in the case of a parametric fire is also highly questionable and more numerical and experimental research in this field is needed. Therefore, the purpose of the presented study is to use advanced calculation methods to investigate the thickness of zero strength layer and parametric charring rates used in effective cross-section method in case of parametric fire. Parametric studies are carried out on a simple solid timber beam that is exposed to a larger number of parametric fire curves Zero strength layer and charring rates are determined based on the numerical simulations which are performed by the recently developed advanced two step computational model. The first step comprises of hygro-thermal model which predicts the temperature, moisture and char depth development and takes into account different initial moisture states of timber. In the second step, the response of timber beam simultaneously exposed to mechanical and fire load is determined. The mechanical model is based on the Reissner’s kinematically exact beam model and accounts for the membrane, shear and flexural deformations of the beam. Further on, material non-linear and temperature dependent behaviour is considered. In the two step model, the char front temperature is, according to Eurocode 5, assumed to have a fixed temperature of around 300°C. Based on performed study and observations, improved levels of charring rates and new thickness of zero strength layer in case of parametric fires are determined. Thus, the reduced cross section method is substantially improved to offer practical recommendations for designing fire resistance of timber structures. Furthermore, correlations between zero strength layer thickness and key input parameters of the parametric fire curve (for instance, opening factor, fire load, etc.) are given, representing a guideline for a more detailed numerical and also experimental research in the future.

Keywords: advanced numerical modelling, parametric fire exposure, timber structures, zero strength layer

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Authors: Guillaume Craveur

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This study shows the opportunity to use numerical tools dedicated to Fire Safety Engineering for the Rolling Stock. Indeed, some lawful requirements can now be demonstrated by using numerical tools. The first part of this study presents the use of modelling evacuation tool to satisfy the criteria of evacuation time for the rolling stock. The buildingEXODUS software is used to model and simulate the evacuation of rolling stock. Firstly, in order to demonstrate the reliability of this tool to calculate the complete evacuation time, a comparative study was achieved between a real test and simulations done with buildingEXODUS. Multiple simulations are performed to capture the stochastic variations in egress times. Then, a new study is done to calculate the complete evacuation time of a train with the same geometry but with a different interior architecture. The second part of this study shows some applications of Computational Fluid Dynamics. This work presents the approach of a multi scales validation of numerical simulations of standardized tests with Fire Dynamics Simulations software developed by the National Institute of Standards and Technology (NIST). This work highlights in first the cone calorimeter test, described in the standard ISO 5660, in order to characterize the fire reaction of materials. The aim of this process is to readjust measurement results from the cone calorimeter test in order to create a data set usable at the seat scale. In the second step, the modelisation concerns the fire seat test described in the standard EN 45545-2. The data set obtained thanks to the validation of the cone calorimeter test was set up in the fire seat test. To conclude with the third step, after controlled the data obtained for the seat from the cone calorimeter test, a larger scale simulation with a real part of train is achieved.

Keywords: fire safety engineering, numerical tools, rolling stock, multi-scales validation

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Authors: Anass Rahouti, Guillaume Salze, Ruggiero Lovreglio, Sélim Datoussaïd

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In healthcare facilities, training the staff for firefighting and evacuation in real buildings is very challenging due to the presence of a vulnerable population in such an environment. In a standard environment, traditional approaches, such as fire drills, are often used to train the occupants and provide them with information about fire safety procedures. However, those traditional approaches may be inappropriate for a vulnerable population and can be inefficient from an educational viewpoint as it is impossible to expose the occupants to scenarios similar to a real emergency. Immersive serious games could be used as an alternative to traditional approaches to overcome their limitations. Serious games are already being used in different safety domains such as fires, earthquakes and terror attacks for several building types (e.g., office buildings, train stations, tunnels, etc.). In this study, we developed an immersive serious game to improve the fire safety skills of staff in healthcare facilities. An accurate representation of the healthcare environment was built in Unity3D by including visual and audio stimuli inspired from those employed in commercial action games. The serious game is organised in three levels. In each of them, the trainee is presented with a specific fire emergency and s/he can perform protective actions (e.g., firefighting, helping non-ambulant occupants, etc.) or s/he can ignore the opportunity for action and continue the evacuation. In this paper, we describe all the steps required to develop such a prototype, as well as the key questions that need to be answered, to develop a serious game for firefighting and evacuation in healthcare facilities.

Keywords: fire safety, healthcare, serious game, training

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Authors: Amritanshu Shriwastav, Purnendu Bose

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Algal photo bioreactors were operated at incident light intensities of 0.24, 2.52 and 5.96 W L-1 to determine the impact of light on algal growth. Low specific Chlorophyll-a content of algae was a strong indicator of light induced stress on algal cells. It was concluded that long term operation of photo bioreactors in the continuous illumination mode was infeasible under the range of incident light intensities examined and provision of a dark period after each light period was necessary for algal cells to recover from light-induced stress. Long term operation of photo bioreactors in the intermittent illumination mode was however possible at light intensities of 0.24 and 2.52 W L-1. Further, the incident light intensity in the photo bioreactors was found to decline exponentially with increase in algal concentration in the reactor due to algal ‘self-shading’. This may be an important determinant for photo bioreactor performance at higher algal concentrations.

Keywords: Algae, algal growth, photo bioreactor, photo-inhibition, ‘self-shading’

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Authors: Damian Czubak

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The Białowieża Forest is a very valuable natural area, included in the World Natural Heritage at UNESCO, where, due to infestation by the bark beetle (Ips typographus), norway spruce (Picea abies) have deteriorated. This catastrophic scenario led to an increase in fire danger. This was due to the occurrence of large amounts of dead wood and grass cover, as light penetrated to the bottom of the stands. These factors in a dry state are materials that favour the possibility of fire and the rapid spread of fire. One of the objectives of the study was to monitor the quantitative and qualitative changes of combustible material on the permanent decay plots of spruce stands from 2012-2022. In addition, the size of the area with highly flammable vegetation was monitored and a classification of the stands of the Białowieża Forest by flammability classes was made. The key factor that determines the potential fire hazard of a forest is combustible material. Primarily its type, quantity, moisture content, size and spatial structure. Based on the inventory data on the areas of forest districts in the Białowieża Forest, the average fire load and its changes over the years were calculated. The analysis was carried out taking into account the changes in the health status of the stands and sanitary operations. The quantitative and qualitative assessment of fallen timber and fire load of ground cover used the results of the 2019 and 2021 inventories. Approximately 9,000 circular plots were used for the study. An assessment was made of the amount of potential fuel, understood as ground cover vegetation and dead wood debris. In addition, monitoring of areas with vegetation that poses a high fire risk was conducted using data from 2019 and 2021. All sub-areas were inventoried where vegetation posing a specific fire hazard represented at least 10% of the area with species characteristic of that cover. In addition to the size of the area with fire-prone vegetation, a very important element is the size of the fire load on the indicated plots. On representative plots, the biomass of the land cover was measured on an area of 10 m2 and then the amount of biomass of each component was determined. The resulting element of variability of ground covers in stands was their flammability classification. The classification developed made it possible to track changes in the flammability classes of stands over the period covered by the measurements.

Keywords: classification, combustible material, flammable vegetation, Norway spruce

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Authors: Pegah Farshadmanesh, Jamshid Mohammadi, Mehdi Modares

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In nearly all earthquakes of the past century that resulted in moderate to significant damage, the occurrence of postearthquake fire ignition (PEFI) has imposed a serious hazard and caused severe damage, especially in urban areas. In order to reduce the loss of life and property caused by post-earthquake fires, there is a crucial need for predictive models to estimate the PEFI risk. The parameters affecting PEFI risk can be categorized as: 1) factors influencing fire ignition in normal (non-earthquake) condition, including floor area, building category, ignitability, type of appliance, and prevention devices, and 2) earthquake related factors contributing to the PEFI risk, including building vulnerability and earthquake characteristics such as intensity, peak ground acceleration, and peak ground velocity. State-of-the-art statistical PEFI risk models are solely based on limited available earthquake data, and therefore they cannot predict the PEFI risk for areas with insufficient earthquake records since such records are needed in estimating the PEFI model parameters. In this paper, the correlation between normal condition ignition risk, peak ground acceleration, and PEFI risk is examined in an effort to offer a means for predicting post-earthquake ignition events. An illustrative example is presented to demonstrate how such correlation can be employed in a seismic area to predict PEFI hazard.

Keywords: fire risk, post-earthquake fire ignition (PEFI), risk management, seismicity

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Authors: K. Nasir, S. Ahmad, A. Khan, H. Benkreira

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The topic of the research is to develop sustainable fire-resistant materials for vibration and acoustic damping of structure and airborne noises from sustainable recycled materials and biodegradable binders. The paper reports, methods and techniques of enhancing fire resistive, vibration and acoustic properties of building insulation materials made from natural resources like wood and recycled materials like rubber and textile waste. The structures are designed to optimize the number, size and stratification of closed (heat insulating) and open (noise insulating) pores. The samples produced are tested for their heat and noise insulating properties, including vibration damping and their structural properties (airflow resistivity, porosity, tortuosity and elastic modulus). The structural properties are then used in theoretical models to check the acoustic insulation measurements. Initial data indicate that one layer of such material can yield as much as 18 times more damping, increasing the loss factor by 18%.

Keywords: fire resistant, vibration damping, acoustic material, vibro-acoustic, thermal insulation, sustainable material, low cost materials, recycled materials, construction material

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Authors: E. Duffin, L. Brownlow

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Arson is a crime which can provide exceptional problems to forensic specialists. Its destructive nature makes evidence much harder to find, especially when used to cover up another crime. There is a consistent potential threat of arsonists seeking new and easier ways to set fires. Existing research in this field primarily focuses on the use of accelerants such as petrol, with less attention to other more accessible and harder to detect materials. This includes the growing speculation of potato and maize-based snacks being used as fire accelerants. It was hypothesized that all ‘crisp-type’ snacks in foil packaging had the potential to act as accelerants and would burn readily in the various experiments. To test this hypothesis, a series of small lab-based experiments were undertaken, igniting samples of the snacks. Factors such as ingredients, shape, packaging and calorific value were all taken into consideration. The time (in seconds) spent on fire by the individual snacks was recorded. It was found that all of the snacks tested burnt for statistically similar amounts of time with a p-value of 0.0157. This was followed with a large mock real-life scenario using packets of crisps on fire and car seats to investigate as to the possibility of these snacks being verifiable tools to the arsonist. Here, three full packets of crisps were selected based on variations in burning during the lab experiments. They were each lit with a lighter to initiate burning, then placed onto a car seat to be timed and observed with video cameras. In all three cases, the fire was significant and sustained by the 200-second mark. On the basis of this data, it was concluded that potato and maize-based snacks were viable accelerants of fire. They remain an effective method of starting fires whilst being cheap, accessible, non-suspicious and non-detectable. The results produced supported the hypothesis that all ‘crisp-type’ snacks in foil packaging (that had been tested) had the potential to act as accelerants and would burn readily in the various experiments. This study serves to raise awareness and provide a basis for research and prevention of arson regarding maize and potato-based snacks as fire accelerants.

Keywords: arson, crisps, fires, food

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Authors: Nikhil Gopalkrishnan, Praveen Bhaskaran, Aditya Bhargava, Gyandeep Bhumarkar

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The present paper is an attempt to perform various Non-Destructive Tests on concrete structure as NDT is gaining a wide importance in the branch of civil engineering these days. Various tests that are performed under NDT not only enable us to determine the strength of concrete structure, but also provide us in-hand information regarding the durability, in-situ properties of the concrete structure. Keeping these points in our mind, we have focused our views on performing a case study to show the comparison between the NDT test results performed on a particular concrete structure and another structure at the same site which is subjected to a continuous fire of say 48-72 hours. The mix design and concrete grade of both the structures were same before the one was affected by fire. The variations in the compressive strength, concrete quality and in-situ properties of the two structures have been discussed in this paper. NDT tests namely Ultrasonic Pulse Velocity Test, Rebound Hammer Test, Core-Cutter Test was performed at both the sites. The main objective of this research is to analyze the variations in the strength and quality of the concrete structure which is subjected to a high temperature fire and the one which isn’t exposed to it.

Keywords: core-cutter test, non-destructive test, rebound hammer test, ultrasonic pulse velocity test

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Authors: Dong Zhang, Kang Hai Tan, Aravind Dasari

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Increasing concern on environmental sustainability and waste management has driven the construction and building sector towards renewable materials. In this work, we have explored the usage of natural fibers as an alternative to synthetic fibers like polypropylene (PP) in ultra-high performance concrete (UHPC). PP fibers are incorporated into concrete to resist explosive thermal spalling of UHPC during a fire exposure scenario. Experimental studies on the effect of natural fiber on the mechanical properties and spalling resistance of UHCP were conducted. The residual mechanical properties of UHPC with natural fibers were tested after heating to different temperatures. Spalling behavior of UHPC with natural fibers is also assessed by heating the samples according to ISO 834 fire curve. A range of analytical, physical and microscopic characterization techniques was also used on the concrete samples before and after being subjected to elevated temperature to investigate the phase and microstructural change of the sample. The findings show that natural fibers are able to improve fire resistance of UHPC. Adding natural fibers can prevent UHPC from spalling at high temperature. This study provides an alternative, which is at low cost and environmentally friendly, to prevent spalling of UHPC.

Keywords: high temperature, natural fiber, spalling, ultra-high performance concrete

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Authors: Claudio Díaz, Mabel Ortiz

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An EFL teacher education programme in Chile takes five years to train a future teacher of English. Preservice teachers are prepared to learn an advanced level of English and teach the language from 5th to 12th grade in the Chilean educational system. In the context of their first EFL Methodology course in year four, preservice teachers have to create a five-minute digital story that starts from a critical incident they have experienced as teachers-to-be during their observations or interventions in the schools. A critical incident can be defined as a happening, a specific incident or event either observed by them or involving them. The happening sparks their thinking and may make them subsequently think differently about the particular event. When they create their digital stories, preservice teachers put technology, teaching practice and theory together to narrate a story that is complemented by still images, moving images, text, sound effects and music. The story should be told as a personal narrative, which explains the critical incident. This presentation will focus on the creation process of 50 Chilean preservice teachers’ digital stories highlighting the critical incidents they started their stories. It will also unpack preservice teachers’ beliefs and reflections when approaching their teaching practices in schools. These beliefs will be coded and categorized through content analysis to evidence preservice teachers’ most rooted conceptions about English teaching and learning in Chilean schools. The findings seem to indicate that preservice teachers’ beliefs are strongly mediated by contextual and affective factors.

Keywords: beliefs, digital stories, preservice teachers, practicum

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Authors: Ahmed Alagha, Belkacem Lamri, Abdelhak Kada.

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Steel-wood assemblies often have complex geometric configurations whose overall behavior under the effect of a fire is conditioned by the thermal response, by combining the two materials steel and wood, whose thermal characteristics are greatly influenced by high temperatures. The objective of this work is to study the thermal behavior of a steel-wood connection, with or without insulating material, subjected to an ISO834 standard fire model. The analysis is developed by the analytical approach using the Eurocode, and numerically, by the finite element method, through the ANSYS calculation code. The design of the connections is evaluated at room temperature taking the cases of single shear and double shear. The thermal behavior of the connections is simulated in transient state while taking into account the modes of heat transfer by convection and by radiation. The variation of temperature as a function of time is evaluated in different positions of the connections while talking about the heat produced and the formation of the carbon layer. The results relate to the temperature distributions in the connection elements as a function of the duration of the fire. The results of the thermal analysis show that the temperature increases rapidly and reaches more than 260 °C in the steel material for an hour of exposure to fire. The temperature development in wood material is different from that in steel because of its thermal properties. Wood heats up on the outside and burns, its surface can reach very high temperatures in points on the surface.

Keywords: Eurocode 5, finite elements, ISO834, simple shear, thermal behaviour, wood-steel connection

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Authors: Michael Dole, Pierre Ninin, Denis Raffourt

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Most of the CERN’s facilities hosting particle accelerators are large, underground and radioactive areas. All fire detection systems installed in such areas, shall be carefully studied to cope with the particularities of this stringent environment. The detection equipment usually chosen by CERN to secure these underground facilities are based on air sampling technology. The electronic equipment is located in non-radioactive areas whereas air sampling networks are deployed in radioactive areas where fire detection is required. The air sampling technology provides very good detection performances and prevent the "radiation-to-electronic" effects. In addition, it reduces the exposure to radiations of maintenance workers and is permanently available during accelerator operation. In order to protect the Super Proton Synchrotron and its 7 km tunnels, a specific long distance aspirating smoke detector has been developed to detect smoke at up to 700 meters between electronic equipment and the last air sampling hole. This paper describes the architecture, performances and return of experience of the long distance fire detection system developed and installed to secure the CERN Super Proton Synchrotron tunnels.

Keywords: air sampling, fire detection, long distance, radioactive areas

Procedia PDF Downloads 129

Authors: F. M. Mohamed, A. Y. Abdelaziz

Abstract:

The subject of petroleum storage tank fires has gained a great deal of attention due to the high cost of petroleum, and the consequent disruption of petroleum production; therefore, much of the current research has focused on petroleum storage tank fires. Also, the number of petroleum tank fires is oscillating between 15 and 20 fires per year. About 33% of all tank fires are attributed to lightning. Floating roof tanks (FRT’s) are especially vulnerable to lightning. To minimize the likelihood of a fire, the API RP 545 recommends three major modifications to floating roof tanks. This paper was inspired by a stroke of lightning that ignited a fire in a crude oil storage tank belonging to an Egyptian oil company, and is aimed at providing an efficient lightning protection system to the tank under study, in order to avoid the occurrence of such phenomena in the future and also, to give valuable recommendations to be applied to floating roof tank projects.

Keywords: crude oil, fire, floating roof tank, lightning protection system

Procedia PDF Downloads 258

Authors: Neha Devi, P. K. Joshi

Abstract:

Fire fuel map is one of the most critical factors for planning and managing the fire hazard and risk. One of the most significant forms of global disturbance, impacting community dynamics, biogeochemical cycles and local and regional climate across a wide range of ecosystems ranging from boreal forests to tropical rainforest is wildfire Assessment of fire danger is a function of forest type, fuelwood stock volume, moisture content, degree of senescence and fire management strategy adopted in the ground. Remote sensing has potential of reduction the uncertainty in mapping fuels. Hyperspectral remote sensing is emerging to be a very promising technology for wildfire fuels characterization. Fine spectral information also facilitates mapping of biophysical and chemical information that is directly related to the quality of forest fire fuels including above ground live biomass, canopy moisture, etc. We used Hyperion imagery acquired in February, 2016 and analysed four fuel characteristics using Hyperion sensor data on-board EO-1 satellite, acquired over the Shiwalik Himalayas covering the area of Champawat, Uttarakhand state. The main objective of this study was to present an overview of methodologies for mapping fuel properties using hyperspectral remote sensing data. Fuel characteristics analysed include fuel biomass, fuel moisture, and fuel condition and fuel type. Fuel moisture and fuel biomass were assessed through the expression of the liquid water bands. Fuel condition and type was assessed using green vegetation, non-photosynthetic vegetation and soil as Endmember for spectral mixture analysis. Linear Spectral Unmixing, a partial spectral unmixing algorithm, was used to identify the spectral abundance of green vegetation, non-photosynthetic vegetation and soil.

Keywords: forest fire fuel, Hyperion, hyperspectral, linear spectral unmixing, spectral mixture analysis

Procedia PDF Downloads 135

Authors: Yanto Santosa, Windi Sugiharti

Abstract:

Fires occur annually in oil palm plantations. The objective of the study was to identify the impact of fire on bird diversity in oil palm plantations. Data of bird diversity were collected using the line transect method. Data were collected from February to March 2017. To estimate species richness, we used the Margalef index, to determine the evenness of species richness between site, we used an Evenness index, and to estimate the similarity of bird communities between different habitat, we used the Sørensen index. The result showed that the number of bird species and species richness in the post burned area was higher than those in unburned area. Different results were found for the Evenness Index, where the value was higher in unburned area that was in post burned area. These results indicate that fires did not decrease bird diversity as alleged by many parties whom stated that fires caused species extinction. Fire trigger the emerging of belowground plant and population of insects as a sources of food for the bird community. This result is consistent with several research findings in the United States and Australia that used controlled fires as one of regional management tools.

Keywords: bird, fire, index of similarity, oil palm, species diversity

Procedia PDF Downloads 213

Authors: Naser Ojaroudi Parchin, Atta Ullah, Haleh Jahanbakhsh Basherlou, Raed A. Abd-Alhameed, Peter S. Excell

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A design of beam-steerable antenna array for the future cellular communication (5G) is presented. The proposed design contains eight elements of compact end-fire antennas arranged on the top edge of smartphone printed circuit board (PCB). Configuration of the antenna element consists of the conductive patterns on the top and bottom copper foil layers and a substrate layer with a via-hole. The simulated results including input-impedance and also fundamental radiation properties have been presented and discussed. The impedance bandwidth (S₁₁ ≤ -10 dB) of the antenna spans from 17.5 to 21 GHz (more than 3 GHz bandwidth) with a resonance at 19 GHz. The antenna exhibits end-fire (directional) radiation beams with wide-angle scanning property and could be used for the future 5G beam-forming. Furthermore, the characteristics of the array design in the vicinity of user-hand are studied.

Keywords: beam-steering, end-fire radiation mode, mobile-phone antenna, phased array

Procedia PDF Downloads 122

Authors: Elinor Bull, Faye Horsley

Abstract:

Abstract Objective: The current study investigated if there was a difference in personality factors in prisoners who had a recorded history of firesetting and who had no recorded history of firesetting. Participants: Participants were 64 male prisoners in a Category B male prison. Participants who had set a fire were identified through the prisons data base, and prisoners who had not set a fire were selected at random. Method: The study used the International Personality Item Pool-50 to measure personality factors, and prisoners who had set a fire were identified through a range of sources accessible to the prison. Analytical evaluation was done by the Multivariate Kruskal Wallis and Mann-Whitney tests. Findings: There was a significant difference between the the firesetting and non-firesetting group in the scores of the personality factor of Contentiousness. Contentiousness was significantly lower in the firesetting sample compared to the non-firesetting sample. Conclusions: Implications for clinical practice and future research are discussed.

Keywords: firesetting, personality, arson, prison, prisoners

Procedia PDF Downloads 57

Authors: Ju-Young Hwang, Hyo-Gyoung Kwak

Abstract:

This paper introduces a numerical analysis method for reinforced-concrete (RC) structures exposed to fire and compares the result with experimental results. The proposed analysis method for RC structure under the high temperature consists of two procedures. First step is to decide the temperature distribution across the section through the heat transfer analysis by using the time-temperature curve. After determination of the temperature distribution, the nonlinear analysis is followed. By considering material and geometrical nonlinearity with the temperature distribution, nonlinear analysis predicts the behavior of RC structure under the fire by the exposed time. The proposed method is validated by the comparison with the experimental results. Finally, prediction model to describe the status of after-cooling concrete can also be introduced based on the results of additional experiment. The product of this study is expected to be embedded for smart structure monitoring system against fire in u-City.

Keywords: RC, high temperature, after-cooling analysis, nonlinear analysis

Procedia PDF Downloads 380

Authors: Qianqian He, Naian Liu, Xiaodong Xie, Linhe Zhang, Yang Zhang, Weidong Yan

Abstract:

In the wild, the vegetation layer with exceptionally complex fuel composition and heterogeneous spatial distribution strongly affects the rate of fire spread (ROS) and fire intensity. Clarifying the influence of fuel bed structure on fire spread behavior is of great significance to wildland fire management and prediction. The packing ratio is one of the key physical parameters describing the property of the fuel bed. There is a threshold value of the packing ratio for ROS, but little is known about the controlling mechanism. In this study, to address this deficiency, a series of fire spread experiments were performed across a discrete fuel bed composed of some regularly arranged laser-cut cardboards, with constant wind speed and different packing ratios (0.0125-0.0375). The experiment aims to explore the relative importance of the internal and surface heat transfer with packing ratio. The dependence of the measured ROS on the packing ratio was almost consistent with the previous researches. The data of the radiative and total heat fluxes show that the internal heat transfer and surface heat transfer are both enhanced with increasing packing ratio (referred to as ‘Stage 1’). The trend agrees well with the variation of the flame length. The results extracted from the video show that the flame length markedly increases with increasing packing ratio in Stage 1. Combustion intensity is suggested to be increased, which, in turn, enhances the heat radiation. The heat flux data shows that the surface heat transfer appears to be more important than the internal heat transfer (fuel preheating inside the fuel bed) in Stage 1. On the contrary, the internal heat transfer dominates the fuel preheating mechanism when the packing ratio further increases (referred to as ‘Stage 2’) because the surface heat flux keeps almost stable with the packing ratio in Stage 2. As for the heat convection, the flow velocity was measured using Pitot tubes both inside and on the upper surface of the fuel bed during the fire spread. Based on the gas velocity distribution ahead of the flame front, it is found that the airflow inside the fuel bed is restricted in Stage 2, which can reduce the internal heat convection in theory. However, the analysis indicates not the influence of inside flow on convection and combustion, but the decreased internal radiation of per unit fuel is responsible for the decrease of ROS.

Keywords: discrete fuel bed, fire spread, packing ratio, wildfire

Procedia PDF Downloads 107

Authors: V. Gareyan, Zh. Gevorkian

Abstract:

We study oblique incident light absorption in opaque media with rough surfaces. An analytical approach with modified boundary conditions taking into account the surface roughness in metallic or dielectric films has been discussed. Our approach reveals interference-linked terms that modify the absorption dependence on different characteristics. We have discussed the limits of our approach that hold valid from the visible to the microwave region. Polarization and angular dependences of roughness-induced absorption are revealed. The existence of an incident angle or a wavelength for which the absorptance of a rough surface becomes equal to that of a flat surface is predicted. Based on this phenomenon, a method of determining roughness correlation length is suggested.

Keywords: light, absorption, surface, roughness

Procedia PDF Downloads 23

Authors: Kohtaroh Miyamoto

Abstract:

As enterprise computing becomes more and more complex, the costs and technical challenges of IT system maintenance and support are increasing rapidly. One popular approach to managing IT system maintenance is to prepare and use an FAQ (Frequently Asked Questions) system to manage and reuse systems knowledge. Such an FAQ system can help reduce the resolution time for each service incident ticket. However, there is a major problem where over time the knowledge in such FAQs tends to become outdated. Much of the knowledge captured in the FAQ requires periodic updates in response to new insights or new trends in the problems addressed in order to maintain its usefulness for problem resolution. These updates require a systematic approach to define the exact portion of the FAQ and its content. Therefore, we are working on a novel method to hierarchically structure the FAQ and automate the updates of its structure and content. We use structured information and the unstructured text information with the timelines of the information in the service incident tickets. We cluster the tickets by structured category information, by keywords, and by keyword modifiers for the unstructured text information. We also calculate an urgency score based on trends, resolution times, and priorities. We carefully studied the tickets of one of our projects over a 2.5-year time period. After the first 6 months, we started to create FAQs and confirmed they improved the resolution times. We continued observing over the next 2 years to assess the ongoing effectiveness of our method for the automatic FAQ updates. We improved the ratio of tickets covered by the FAQ from 32.3% to 68.9% during this time. Also, the average time reduction of ticket resolution was between 31.6% and 43.9%. Subjective analysis showed more than 75% reported that the FAQ system was useful in reducing ticket resolution times.

Keywords: FAQ system, resolution time, service incident tickets, IT system maintenance

Procedia PDF Downloads 309