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Background: Common causes of air leakage around an endotracheal tube include insufficient endotracheal tube cuff inflation and damage to the cuff, while damage to the pilot balloon or pilot balloon tubing is relatively rare. Case presentation: A 74-year-old female with vertebral osteomyelitis was scheduled for an extreme lateral interbody fusion followed posterior fixation. A fiber-optic light was utilized as part of the surgical illuminator. A sudden decrease in tidal volume and airway pressure was noted intraoperatively. We suspected leakage around the endotracheal tube cuff; however, no decrease in cuff pressure was detected. Despite the normal cuff pressure, we decided to inject a small amount of air which led to a significant increase in the cuff pressure. Upon careful inspection of the endotracheal tube, we discovered that the pilot balloon tubing was damaged as a result of thermal energy emitted by the fiber-optic light, which had ignited the surgical drape. The pilot balloon tubing was partially severed in which the section proximal to the endotracheal tube cuff was burned and punctured, causing the cuff leak. Meanwhile, the section proximal to the pilot balloon had melted and occluded the lumen, resulting in a falsely normal cuff pressure reading followed by an elevated cuff pressure when a small amount of air was injected into the pilot balloon during troubleshooting. Appropriate ventilation was resumed after extubation and re-intubation with a new endotracheal tube. Conclusions: We experienced an endotracheal tube cuff leakage caused by a damaged pilot balloon tubing due to thermal energy of the fiber-optic light. Our case report emphasizes the importance of suspecting damage to the endotracheal tube cuff and inflation system despite a normal cuff pressure reading, given that the measurement may be falsely elevated depending on the specific location of the damage. In addition, all operating personnel should be familiarized with safety warnings and cautions related to handling. [ABSTRACT FROM AUTHOR]

Copyright of Urban Mass Transit is the property of Urban Mass Transit Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Industrial Minerals & Processing / Huagong Kuangwu yu Jiagong is the property of Industrial Minerals & Processing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Safety characteristics are used to keep processes, including flammable gases, vapors, and combustible dusts, safe. In the standards for the determination of safety characteristics of gases and vapors, the induction spark is commonly used. However, classic transformers are hard to obtain, and replacement with new electronic transformers is not explicitly allowed in the standards. This article presents the investigation of five gases that are normally used to calibrate devices for the determination of safety characteristics, the maximum experimental safe gap (MESG), with an electronic transformer, and the values are compared to the ones that are obtained with the standard transformer. Additionally, calorimetric measurements on the net energy of both ignition sources were performed as well as open-circuit voltage measurements. It is concluded that the classic type of transformer can be replaced by the new type obtaining the same results for the MESG and introducing the same amount of energy into the system. [ABSTRACT FROM AUTHOR]

Flameproof enclosures are widely installed as safety equipment at dangerous industrial sites to reduce ignition risks. However, electrical components typically installed in such flameproof enclosures for the production process can cause ignition and compromise the safety of the enclosures. Thus, in such cases, the explosive characteristics of the flameproof enclosures is severely affected. Accidental gas explosions in industrial sites rarely occur under standard operating conditions. Premixed gas explosions in flameproof shells are complex processes. A 560 mm × 400 mm × 280 mm flameproof enclosure commonly used in industrial sites was used to investigate the phenomenon. The explosion characteristics of ethylene-air premixed gas in the flameproof enclosure was simulated using FLUENT software to investigate the influences of ignition source location, ignition source energy, ambient temperature, and obstacles on the maximum explosion pressure, maximum explosion pressure rise rate, and maximum explosion index of the flameproof enclosure. The results revealed that the surface area of heat exchange considerably influences the maximum explosion pressure of the flameproof enclosure. The larger the ignition energy is, the larger the maximum explosion pressure value, the maximum rate of explosion pressure rise, and the maximum explosion index of the flameproof enclosure are. With the increase in the ambient temperature, the maximum explosion pressure decreased, whereas the maximum rate of explosion pressure rise and the maximum explosion index exhibited limited change. The results of this study provide theoretical guidance for the design and suppression of flameproof enclosures. [ABSTRACT FROM AUTHOR]

The complexity and concealment of the goaf environment hinder the understanding of the types of ignition sources in goaf gas explosions. Therefore, this study constructed a mechanical-electrical test system for rocks; the generation of pressure stimulated currents (PSCs) and its discharge-induced ignition mechanism of roof sandstone under uniaxial compression were explored, and the real ignition source of the gas explosion accident in Babao Coal Mine was revealed. The experimental results reveal that the intensity of PSCs of sandstone is higher than that of marble in the loading stage because the piezoelectric effect of quartz in sandstone enhances its mechanical-electrical sensitivity and leads to an increase in the discharge intensity. During the whole loading stage, the PSCs signals generated by sandstone are mainly attributable to the piezoelectric effect of quartz, while the PSCs of marble are mainly caused by the sliding friction between mineral particles. When the samples are in the compaction and elastic stages, PSCs are proportional to strain rate and stress rate respectively; when the samples enter the stage of plastic deformation and failure, the peak values of PSCs are positively correlated with the uniaxial compressive strength. Sparks can be seen in sandstone during the failure stage, which mainly results from electron avalanche caused by the damage of quartz grains under loading. The ignition source of the gas explosion accident in Babao Coal Mine is more likely to be sparks generated by the combined discharge of the extrusion friction and piezoelectric effect of roof sandstone, rather than coal spontaneous combustion. [ABSTRACT FROM AUTHOR]

Copyright of Transactions the Japan Society of Refrigerating & Air Conditioning Engineers is the property of Japan Society of Refrigerating & Air Conditioning Engineers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Fuel moisture content is one of the important factors that determine ignition probability and fire behaviour in forest ecosystems. In this study, ignition and fire spread moisture content thresholds of 40 dead fuel were performed in laboratory experiments, with a focus on the source of ignition and wind speed. Variability in fuel moisture content at time of ignition and during fire spread was observed for different fuels. Matches were more efficient to result in ignition and spread fire with high values of fuel moisture content compared to the use of cigarette butts. Some fuels did not ignite at 15% moisture content, whereas others ignited at 40% moisture content and fire spread at 38% moisture content in the case of matches, or ignited at 27% moisture content and spread fire at 25% moisture content using cigarette butts. A two-way ANOVA showed that both the source of ignition and the wind speed affected ignition and fire spread threshold significantly, but there was no interaction between these factors. The relationship between ignition and fire spread was strong, with R2 = 98% for cigarette butts, and 92% for matches. Further information is needed, especially on the density of fuels, fuel proportion (case of mixed fuels), fuel age, and fuel combustibility. [ABSTRACT FROM AUTHOR]

The temperature, velocity, and size of hot metal sparks are essential to understanding their ability to ignite flammable materials. However, existing measurement methods have limitations to achieve detailed, in situ measurements of these parameters. This paper describes a methodology that combines color-ratio pyrometry and particle streak tracing velocimetry, together with digital image processing to obtain non-intrusive measurements of the temperature, velocity, and size of multiple sparks in a spray. Furthermore, these measurements can be performed using a properly calibrated commercially available color digital camera. The principle of the measurement is firstly introduced, and the repeatability and accuracy of the method are validated via a designed experiment. Then the method is performed to measure the temperature and velocity of metal (steel) sparks in sprays generated by abrasive cutting. Measurements of initial spark temperatures and velocities are reported, as well as the evolution of the temperature and velocity along the flight path of the sparks. Observed initial spark temperature in this work mostly ranged within 1500°C to 1700°C. Results show evidence of both melting and oxidation of the sparks. Different blade speeds are used to understand their effect on spark velocity and temperature. The results of this study can be used as input parameters for spark oxidation and transport models, which in turn can be used to assess the hazards of spark sprays in wildland spot fires, ignition, explosions of flammable gaseous mixtures and dust clouds, and for monitoring and optimizing the material processes such as thermal-spray coating. [ABSTRACT FROM AUTHOR]

Surgically induced fire is a life-threatening hazard; this topic has received little attention, although only 3 factors, the so-called fire triad, are needed for surgical fires to occur: an oxidizer, fuel and an ignition source. This systematic review aims to determine the impact of each component and to delegate every staff member an area of responsibility, thus ensuring patient health through prevention or protection. The trial was registered in Prospero CRD42018082656. A database search of eligible, preferably evidence-based studies was conducted. The Robins-I tool for assessing the risk of bias revealed a moderate risk of bias. Due to insufficient data, the main findings of these studies could not be summarized through a quantitative synthesis; therefore, a qualitative synthesis is outlined. The results are summarized according to the roles of the fire triad and discussed. (1) Role of the oxidizer: oxygen is the key component of the triad. Safe oxygen delivery is important. An oxygen-enriched environment (ORE) is caused by draping and is preferably prevented by suctioning. Fuel characteristics are affected by varying oxygen concentrations. (2) Role of the ignition source: electrocauterization is the most common ignition source, followed by lasers. Less common ignition sources include fiberoptic cables and preparative solutions, petrol or acetone. (3) Role of the fuel: surgical drapes are one of the most common fuels for surgical fires followed by the patient's hair and skin. Skin preparation solutions are among the less common fuels. Many fire-resistant materials have been tested that do not remain fire resistant in ORE. It was concluded that the main problem is defining the real extent of this hazard. Exact numbers and exact condition protocols are needed; therefore, standardized registration of every fire and future studies with much evidence are needed. Immediate prevention consists of close attention to patient safety to prevent surgical fires from happening. [ABSTRACT FROM AUTHOR]

Background and Overview. Fire risk is present whenever there is a convergence of fuel, oxidizer, and an ignition source, which is called the fire triangle. A heightened awareness of fire risk is necessary whenever a fire triangle is present. The authors provide a sentinel event case report of fire in a dental office. Case Description. A 72-year-old woman received second-degree facial burns from a fire that ignited near the nasal hood supplying a nitrous oxide-oxygen mixture. The presumed ignition source was heat generated during the preparation of a titanium post with a high-speed, irrigated carbide bur. The patient was transferred to the local emergency department and subsequently discharged after possible pulmonary complications were ruled out. The patient was then transferred to a regional burn unit and was discharged home with second-degree burns. Conclusions and Practical Implications. When the source of a fuel cannot be removed from the immediate area, soaked with water, or covered with a water-soluble jelly, the dentist should stop the open flow of oxygen or nitrous oxide-oxygen mixtures to the patient for 1 minute before the use of a potential ignition source, and intraoral suction should be used to clear the ambient atmosphere of oxidizer-enriched exhaled gas. [ABSTRACT FROM AUTHOR]

An appraisal was undertaken of the key factors involved in explosion and combustion processes mainly associated with the fogging of chlorpropham formulations into potato stores. The key factors considered are source of ignition, solvents, explosive limits of solvents, the presence and atmospheric concentrations of particulate clouds and the role of particulate material in dust explosions. Also the sequence of events that takes place in a dust explosion, including critical concentrations of dust required to initiate the reactions involved and the particular relevance of the above events to the behaviour of chlorpropham fogs both at the time of application and when distributed throughout a store. The relevance of fine dust already present in the store to the initiation of explosions, particularly secondary explosions, which are considered to be a major cause of concern due to their severity, is also emphasised. [ABSTRACT FROM AUTHOR]