Start Of Fire Research Articles

Wintertime aerosol optical and radiative properties in the Kathmandu Valley during the SusKat-ABC field campaign

Abstract. Particulate air pollution in the Kathmandu Valley has reached severe levels that are mainly due to uncontrolled emissions and the location of the urban area in a bowl-shaped basin with associated local wind circulations. The AERONET measurements from December 2012 to August 2014 revealed a mean aerosol optical depth (AOD) of approximately 0.30 at 675 nm during winter, which is similar to that of the post-monsoon but half of that of the pre-monsoon AOD (0.63). The distinct seasonal variations are closely related to regional-scale monsoon circulations over South Asia and emissions in the Kathmandu Valley. During the SusKat-ABC campaign (December 2012–February 2013), a noticeable increase in both aerosol scattering (σs; 313 → 577 Mm−1 at 550 nm) and absorption (σa; 98 → 145 Mm−1 at 520 nm) coefficients occurred before and after 4 January 2013. This can be attributed to the increase in wood-burned fires due to a temperature drop and the start of firing at nearby brick kilns. The σs value in the Kathmandu Valley was a factor of 0.5 lower than that in polluted cities in India. The σa value in the Kathmandu Valley was approximately 2 times higher than that at severely polluted urban sites in India. The aerosol mass scattering efficiency of 2.6 m2 g−1 from PM10 measurements in the Kathmandu Valley is similar to that reported in urban areas. However, the aerosol mass absorption efficiency was determined to be 11 m2 g−1 from PM10 measurements, which is higher than that reported in the literature for pure soot particles (7.5 ± 1.2 m2 g−1). This might be due to the fact that most of the carbonaceous aerosols in the Kathmandu Valley were thought to be mostly externally mixed with other aerosols under dry conditions due to a short travel time from their sources. The σs and σa values and the equivalent black carbon (EBC) mass concentration reached up to 757 Mm−1, 224 Mm−1, and 29 µg m−3 at 08:00 LST (local standard time), respectively but decreased dramatically during the daytime (09:00–18:00 LST), to one-quarter of the morning average (06:00–09:00 LST) due to the development of valley winds and an atmospheric bounder layer. The σs and σa values and the EBC concentration remained almost constant during the night at the levels of 410 Mm−1, 130 Mm−1, and 17 µg m−3, respectively. The average aerosol direct radiative forcings over the intensive measurement period were estimated to be −6.9 ± 1.4 W m−2 (top of the atmosphere) and −20.8 ± 4.6 W m−2 (surface). Therefore, the high atmospheric forcing (i.e., 13.9 ± 3.6 W m−2) and forcing efficiency (74.8 ± 24.2 W m−2 τ−1) can be attributed to the high portion of light-absorbing aerosols in the Kathmandu Valley, as indicated by the high black carbon (or elemental carbon) to sulphate ratio (1.5 ± 1.1).

Reaction Control Thruster Thermal Design for a Mission to Mercury

This paper describes two novel methods used to reduce the prefiring injector temperatures of thrusters on the sun-facing side of a spacecraft designed for a mission to Mercury. The Mercury Transfer Module is the propulsion module that takes the European Space Agency’s BepiColombo mission to the planet Mercury. It contains a bipropellant chemical propulsion system and a xenon-based electric propulsion system. It was predicted that, within a certain distance from the sun, the high solar loads and large internal waste heat from the electric propulsion would cause vapor lock to occur on the sun-facing hydrazine thrusters at the start of firing, rendering their performance unpredictable and inefficient. The paper reports on the development of a method to increase the emissivity of the nozzles via sandblasting and on the development of a special copper collar for directly removing heat from the injector. The design and analysis are reported, along with results from a dedicated thruster-level high solar flux thermal test and a full spacecraft-level thermal test using a flight-representative thruster to which the modifications as described in this paper. The two techniques are shown to enable unrestricted use of the thrusters all the way to Mercury.

Application of a CA-based model to predict the fire front in Hyrcanian forests of Iran

Forest fire is one of the most important source of land degradation that lead to deforestation and desertification processes. Thus, prediction of forest fire front is necessary to control it. In this study, Alexandridis model based on Cellular Automata (CA) rules was applied to predict the fire front in a part of Hyrcanian forests of Iran. The data of effective factors on fire front in the model (including vegetation type and density, wind speed and direction, and ground elevation) were provided from Mazandaran Natural Resources Administration (MNRA), Mazandaran Meteorological Administration (MMA), and Digital Elevation Model (DEM) of ASTER sensor. The model was used to simulate the front of a wildfire that burned a part of District Three of Neka-Zalemroud forests (DTNZ) on December of 2010. The required data of actual fire for simulation of fire front (including actual fire map, fire area, fire start point, etc.) were provided from MNRA. All effective factors maps for actual fire confine were organized in a Geographic Information System (GIS). The simulation environment was provided based on the ASCII files of altitude, vegetation density, and vegetation type matrices, together with a matrix containing the burned area. The fire front model was programmed and it was implemented by uploading of all digital layers (coding ASCII matrices) of effective variables and considering of the certain wind speed and direction in fire confine. Fire front simulation was run by considering of fire start point coordination and the fire front simulation was depicted. Finally, the number of burned and unburned cells in fire confine matrix was obtained. Results of model implementation including fire front direction and shape were compared with the actual fire confine to evaluate the accuracy of the used model qualitatively. Thus, the fire front polygon was overlaid on the actual fire polygon and the high similarity was observed between them. In addition, total accuracy and Kappa index were used to evaluate the accuracy of the used model quantitatively. The total accuracy and Kappa index were obtained 0.88 and 0.74, respectively. These results can show the accuracy of CA-based model to predict the fire front in Hyrcanian forests of Iran in current research.

Evolution of Submicrometer Organic Aerosols during a Complete Residential Coal Combustion Process.

In the absence of particulate matter (PM) control devices, residential coal combustion contributes significantly to ambient PM pollution. Characterizing PM emissions from residential coal combustion with high time resolution is beneficial for developing control policies and evaluating the environmental impact of PM. This study reports the evolution of submicrometer organic aerosols (OA) during a complete residential coal combustion process, that is, from fire start to fire extinction. Three commonly used coal types (bituminous, anthracite, and semicoke coals) were evaluated in a typical residential stove in China. For all three types of coal, the OA emission exhibited distinct characteristics in the four stages, that is, ignition, fierce combustion, relatively stable combustion, and ember combustion. OA emissions during the ignition stage accounted for 58.2-85.4% of the total OA emission of a complete combustion process. The OA concentration decreased rapidly during the fierce combustion stage and remained low during the relatively stable combustion stage. During these two stages, a significant ion peak of m/z 73 from organic acids were observed. The degree of oxidation of the OA increased from the first stage to the last stage. Implications for ambient OA source-apportionment and residential PM emission characterization and control are discussed.

Neandertals may have used chemistry to start fires

Neandertals may have used chemistry to start fires

Measurement of inter- and intra-annual variability of landscape fire activity at a continental scale: the Australian case

Climate dynamics at diurnal, seasonal and inter-annual scales shape global fire activity, although difficulties of assembling reliable fire and meteorological data with sufficient spatio-temporal resolution have frustrated quantification of this variability. Using Australia as a case study, we combine data from 4760 meteorological stations with 12 years of satellite-derived active fire detections to determine day and night time fire activity, fire season start and end dates, and inter-annual variability, across 61 objectively defined climate regions in three climate zones (monsoon tropics, arid and temperate). We show that geographic patterns of landscape burning (onset and duration) are related to fire weather, resulting in a latitudinal gradient from the monsoon tropics in winter, through the arid zone in all seasons except winter, and then to the temperate zone in summer and autumn. Peak fire activity precedes maximum lightning activity by several months in all regions, signalling the importance of human ignitions in shaping fire seasons. We determined median daily McArthur forest fire danger index (FFDI50) for days and nights when fires were detected: FFDI50 varied substantially between climate zones, reflecting effects of fire management in the temperate zone, fuel limitation in the arid zone and abundance of flammable grasses in the monsoon tropical zone. We found correlations between the proportion of days when FFDI exceeds FFDI50 and the Southern Oscillation index across the arid zone during spring and summer, and Indian Ocean dipole mode index across south-eastern Australia during summer. Our study demonstrates that Australia has a long fire weather season with high inter-annual variability relative to all other continents, making it difficult to detect long term trends. It also provides a way of establishing robust baselines to track changes to fire seasons, and supports a previous conceptual model highlighting multi-temporal scale effects of climate in shaping continental-scale pyrogeography.

Проблемы обеспечения тушения пожаров на объектах энергетики оперативными подразделениями пожарной охраны

A contingency beginning at power facility can result into emergency mode of operation. Amount of fires at power facilities reduces, while direct damage increases. Overall material loss at power facilities mostly forms by large fires consequences. As well indirect damage caused by induced closedown of power facilities can also have social character expressed in large part of population vital abnormality. Fire consequences minimization at power facility should be gained by fire fighting timeliness. Along with fire fighting start time minimization continuity of fire fighting from starting fire fighting agent supply up to fire suppression is fundamental. It implies fire fighting forces and equipment concentration in good supply for fire isolation in size it gained by the time fire fighting initiates. The largest complexity in fire fighting at power facilities is smoke screening of burning and related areas. Limiting factor of fire fighter's residence time in conditions of dangerous fire factors is protective equipment protective power time. It's naturally that it must exceed fire fighting time. Figuring measures of fire fighters at power facilities continued supplying should be conducted as protective power time of protective equipment against dangerous fire factors is less then fire fighting time. Demonstrative fact is that use of respiratory protection equipment increases against the background of reducing number of fires at power facilities. Ensuring fire fighting at power facilities has feature of necessity for power facilities survival and resulting necessity for personnel work capability in case of fire. Therefore timeliness of power facilities fire fighting is possible to achieve by improvement of following directions: 1) providing visibility improvement and reducing exposure to smoke in fire condition of power facilities; 2) fire fighter's life support and operability assurance at power facilities; 3) developing protection methods and protective equipment from fire hazards for fire fighters at power facilities; 4) advancing fire fighter's operational and physical specifications in providing fire fighting at power facilities.

'I don't want to cause any trouble': the attitudes of hospital patients towards patient empowerment strategies to reduce healthcare-acquired infections.

Patients have, traditionally, been assumed to be the passive party in the healthcare-associated infections equation, with relatively little research focused on the patients' perspective. This study aimed to explore the attitudes of hospital patients towards patient empowerment as one of the key components of patient engagement. Semi-structured interviews were undertaken with surgical patients from a major public hospital in Sydney, Australia. While participants acknowledged that patients could play a role in preventing infections while in hospital, that role was largely associated with maintaining their own personal hygiene. No reference was made to patients interacting with staff members. Some participants said that they would feel comfortable and happy to engage with staff, while others voiced concerns. Some about not wanting to 'cause trouble or start fires' and therefore would not tell staff members to perform hand hygiene. Some participants articulated a fear that their care may be negatively affected if they directly engaged or confronted clinicians about their behaviours. We found that patient engagement remains an underused method of preventing healthcare-associated infections, and the deep-seated public fears about individual vulnerabilities still need to be addressed.

Self-reports and Observer Reports as Data Generation Methods: An Assessment of Issues of Both Methods

Data collection through the self-report method can allow one to acquire both a different type and quality of information when compared to acquiring the information through the observer report method; however nor the observation or self-report processes are perfect data collection methods. When designing a study it is important to know when to use one over the other. By understanding how the data is collected in both of these processes and the problems associated with either process one can make an informed decision as to when to use one over the other. Additionally, though the use of only one method can be a practical choice the use of both methods is the better choice and should be used when it can. It should be noted that there are many problems and biases that need to be controlled for in these methods and there are other ways in which they can be controlled for beyond what is covered, however, this paper will be limited to the stated biases and control methods. Throughout my involvement in ‘The Fire Starter Study' I have come to understand the process of how these methods are conducted and why they are conducted the way they are.

Smart and Low Cost Technique for Forest Fire Detection using Wireless Sensor Network

line of sight and the early stage of the fire process problem could be solved with the second type of sensors. A new technology called Wireless Sensor Network (WSN) is nowadays receiving more attention and has started to be applied in forest fire detection. The Wireless nodes integrate on the same printed circuit board, the sensors, the data processing, the wireless transceiver and they all consume power from the same source- batteries. Unlike cell phones, WSN do not have the capability of periodic recharging. The sensors are devices capable of sensing their environment and computing data. The sensors sense physical parameters such as the temperature, pressure and humidity, as well as chemical parameters such as Carbon Monoxide, Carbon Dioxide and Nitrogen Dioxide. The sensors operate in a self-healing and self-organising wireless networking environment. One type of wireless technology is ZigBee which is a new industrial standard based on IEEE 802.15.4. This technology emphasises low cost battery powered application and small solar panels and is suited for low data rates and small range communications. Wireless Sensor Networks have seen rapid developments in a large number of applications. This kind of technology has the potential to be applied almost everywhere; this is why the research interest in sensor networks is becoming bigger and bigger every year. Forest fire detection and prevention is another real problem faced by a number of countries. Different methods for monitoring the emergence of fires have been proposed. The early methods were based on manned observation towers but this technique was inefficient and not entirely effective. Subsequently, camera surveillance systems and satellite imaging technologies were tried but this also proved ineffective at being able to efficiently monitor the initial start of the surface fire. For example, camera networks can be installed in different positions in the forests but these provide only line of sight pictures and may be affected by weather conditions and/or physical obstacles.

Early forest fire detection using low-energy hydrogen sensors

Abstract. Most huge forest fires start in partial combustion. In the beginning of a smouldering fire, emission of hydrogen in low concentration occurs. Therefore, hydrogen can be used to detect forest fires before open flames are visible and high temperatures are generated. We have developed a hydrogen sensor comprising of a metal/solid electrolyte/insulator/semiconductor (MEIS) structure which allows an economical production. Due to the low energy consumption, an autarkic working unit in the forest was established. In this contribution, first experiments are shown demonstrating the possibility to detect forest fires at a very early stage using the hydrogen sensor.

Human behaviour in fire: should the fire service stop telling and start listening?

Purpose – The purpose of this paper is to outline the work being carried out by Kent Fire and Rescue Service (KFRS) to build a comprehensive database of the behaviours and motivations of those experiencing accidental fires occurring in dwellings. It is an approach that is predicated upon the desire to listen to and learn from those who actually experience such fires. Design/methodology/approach – The work started with a qualitative pilot study, comprising ten semi-structured, in-depth interviews with those who experienced injuries in accidental dwelling fires (ADFs). This informed the design of the subsequent post-ADF questionnaire survey. Findings – The paper demonstrated a strong desire among interviewees to tackle the fire themselves. The paper highlights a number of risk factors and also found that decisions to call the fire service were often secondary to other aims and concerns, including issues related to shame and guilt. Research limitations/implications – The small sample size means that the data have no statistical validity. Practical implications – The project offers a variety of benefits to all aspects of the UK fire service. The work's success and national implications have generated a large amount of interest in the sector, resulting KFRS working with other fire and rescue services in South East England to adopt it as a regional project. Originality/value – The work marks, arguably, the first attempt in almost 30 years to develop a comprehensive understanding of human behaviour in dwelling fires.

Analysis of forest fires causes and their motivations in northern Algeria: the Delphi method

Abstract: Forest fires in Algeria are mostly human-caused and result from local social behavior, whether voluntary (arson) or involuntary (negligence). Understanding the reasons why fires start is, therefore, a crucial factor in preventing or reducing their incidence, developing significant prevention efforts and designing specific fire prevention campaigns. The Delphi method is a promising tool for improving knowledge about how fire starts and why, and above all helps reduce the number of fires started by unknown causes, the majority type in Algeria. The Delphi method uses a set of procedures for eliciting and refining the opinions of a panel of experts on a particular subject of interest. This method was used in three case studies, in coastal or inner wilayas (provinces) selected from a highly fire-prone area in north-central Algeria. Results showed the traditional use of fire in agriculture and forestry, in situations related to land use changes and in interpersonal conflicts are the major causes of voluntary fires. For involuntary events (negligence), experts unanimously identified the importance of the restart of fire, caused by fire crews who do not ensure the mopping up of controlled fires (91.49%) and the negligent use of agricultural fires, particularly stubble burning (80.14%). For voluntary fires (arson), results highlight the importance of fires set for land use changes (77.30%), pyromania (67.38%) and honey gathering (62.41%). Illegal dumping and burning of garbage was also mentioned by responders in all study-areas.

The Fire Starter and the Brand Steward

This article seeks to uncover the complexities of the creative director's leadership role in advertising agencies. The authors based their work on data received from six agencies and 43 interviews conducted at those participating agencies. Findings suggest successful creative directors combine expertise in creativity, strategy, and interpersonal communication to motivate and mentor co-workers, oversee brand identities, serve as liaisons between creative people and other agency departments and clients, and shape the creative vision of the agency. [ABSTRACT FROM AUTHOR]

Analysis of danger management by highway users confronted with a tunnel fire

The aim of this article is to show that risk-management behaviors of highway users in tunnel-fire situations are dependent on their knowledge of safety devices and their danger-handling behavior. We hypothesized that the unpredictability of the circumstances in which fires start, as well as drivers’ lack of knowledge about safety devices, are likely to have an impact on their behavior. The present study is a detailed analysis of actual fires that have occurred in tunnels, with a close examination of users’ evacuation strategies and procedures. In our analysis of 11 tunnel fires, we studied driver behaviors and the strategies they use to cope with a fire. The tunnel users in these fires encountered difficulties both in perceiving signs of danger and in receiving warnings of the danger. The analysis showed that they engaged in a variety of evacuation behaviors and implemented few collective strategies to protect themselves. The problems were related to poor design or equipment, difficulty using safety devices or processing information, or a lack of emergency signals. Some recommendations are made regarding ways of modifying existing prevention and warning devices in view of promoting safer choices among the available options.

Optical Modeling of Fire Hazards Arising from Sunlight Focused by Water

Anecdotal accounts of water-filled containers starting fires by focusing sunlight occasionally appear in the popular press, typically as curiosity items. This paper demonstrates the use of optical modeling tools and methodologies to explore situations under which water-filled containers can concentrate sunlight sufficiently to start fires, and proves the existence of a real hazard with an experimental demonstration.

Simulation of fire scenarios due to different vehicle types with and without traffic in a bi-directional road tunnel

This paper presents findings obtained by CFD modelling for simulating the effects of fire due to different vehicle types in a bi-directional road tunnel. Four different burning vehicles placed in the centre of the driving lane at tunnel middle length were considered. Peaks of the heat release rate (HRR) of: 8, 30, 50, and 100MW were simulated for the two cars, the bus, the heavy goods vehicle (HGV), and the petrol tanker, respectively. The fire effects on tunnel structure and on environmental conditions along people evacuation path were especially evaluated. The effects of the traffic jam, in contrast with the isolated vehicles, on temperatures, radiant heat flux, visibility distance, and toxic gases concentrations, were also investigated. The worst scenario was identified to be that pertaining to the petrol tanker and more critical conditions were also found when the tunnel was full of vehicles. The maximum gas temperatures reached in the presence of traffic at the side wall (and at the tunnel ceiling reported in brackets) were found to be: 360°C (170°C) for the two cars; 740°C (465°C) for the bus; 835°C (735°C) for the HGV and 1305°C (1145°C) for the petrol tanker, respectively. The presence of the traffic, in contrast with the isolated vehicle, involved an increase in the maximum temperatures equal to 16–17% for the two cars, and contained in the range 12–29% with percentages increasing starting from the tanker, to the HGV and to the bus. In other words when the maximum temperatures produced by the isolated vehicle are very high (e.g. for the tanker), the presence of the traffic had a minor effect. With reference to environmental conditions along the evacuation path, the results showed that in the case of petrol tanker fire the emergency ventilation ensures a tenable level of temperature, radiant heat flux, and toxic gases concentrations up to 5min from the fire starting. This time increases up to 6.5min for the HGV and 8min for the bus. This means that the tunnel users in order to be safe in all scenarios should leave the tunnel within 5min after the fire starting. Toxic gases concentrations, however, were found to be below the limit values in all cases and also in the presence of traffic. In the light of the aforementioned results, tunnel occupants should be promptly informed of the fire risk and guided to the exit portals. This might be done by equipping the tunnel with illuminated emergency signs located along the tunnel length and by installing traffic lights before the entrances so that the tunnel can be closed in case of emergency. By activating the traffic lights at the portals and the emergency signs (more especially those at the ceiling) at the same time as the emergency ventilation is activated, safer conditions for the people evacuation are expected.

Words to Start Fires

Words to Start Fires

Words to Start Fires

Every hairdresser I’ve gone to in the last fi ve years has said “try younger men.” Rinse the dead out of your cells with alcohol or fl ame, ink and needles. Th e pain you choose is diff erent. “Why isn’t there more meat on this chicken?” he asked me, squeezing my ribs till they bruised. Every slap was an accident, and he would stand over me, beating himself off and crying. My father spent nights in the bathroom reading Jokes for the John. My older sister drew concentric circles on that door and made me wash it clean and apologize. My body walked me places I had never been, tucked safe in an inside pocket. Be quiet and good and bad things will happen.

Fires on trees

We consider random dynamics on the edges of a uniform Cayley tree with $n$ vertices, in which edges are either inflammable, fireproof, or burt. Every inflammable edge is replaced by a fireproof edge at unit rate, while fires start at smaller rate $n^{-\alpha}$ on each inflammable edge, then propagate through the neighboring inflammable edges and are only stopped at fireproof edges. A vertex is called fireproof when all its adjacent edges are fireproof. We show that as $n\to \infty$, the density of fireproof vertices converges to $1$ when $\alpha>1/2$, to $0$ when $\alpha<1/2$, and to some non-degenerate random variable when $\alpha=1/2$. We further study the connectivity of the fireproof forest, in particular the existence of a giant component.