Fire safety

消防安全
  • 文章类型: Journal Article
    本研究的目标是开发模拟火灾的视频集合,以调查人们如何看待不断增长的建筑火灾。在消防安全科学中,居住者对建筑火灾反应的一个关键因素是移动前时期,取决于个人在初期发生火灾时采取保护行动需要多长时间。研究导致运动前持续时间的心理过程的关键是向人类受试者展示建筑物火灾。先前研究中使用的一种方法是通过场景向个人呈现建筑物火灾的视频。用于模拟火灾动力学的数值模拟可用于渲染这些场景的视频。然而,这种模拟主要用于消防工程中,以设计建筑物,而社会科学家相对无法访问。
    本研究记录了一系列视频,基于数值模拟,研究人员可以用它来研究人类在火灾中的行为。这些视频显示了不同类型房间中正在发生的火灾,以不同的速度生长,不同的烟雾厚度,在其他特征中。作为验证研究的一部分,向参与者展示了视频片段的子集,并要求参与者对模拟火灾带来的感知风险进行评分.
    我们观察到,等级随火灾的强度和增长率而变化,烟雾不透明度,房间的类型,以及火灾中的视点所在的位置。这些影响与以前的火灾科学研究中观察到的影响一致,提供证据证明视频可以通过火灾模拟引发感知到的风险。本研究表明,未来的研究可以利用火灾模拟的视频库来研究人类对建筑物火灾发展的看法,因为情境因素被系统地操纵。
    UNASSIGNED: The goal of the present research was to develop a video collection of simulated fires to investigate how people perceive growing building fires. In fire safety science, a critical factor to occupant responses to building fires is the pre-movement period, determined by how long it takes an individual to initiate taking protective action with an incipient fire. Key to studying the psychological processes that contribute to the duration of the pre-movement period is presenting human subjects with building fires. One approach used in previous research is to present videos of building fires to individuals via scenarios. The numerical simulations used to model fire dynamics can be used to render videos for these scenarios. However, such simulations have predominantly been used in fire protection engineering to design buildings and are relatively inaccessible to social scientists.
    UNASSIGNED: The present study documents a collection of videos, based on numerical simulations, which can be used by researchers to study human behavior in fire. These videos display developing fires in different types of rooms, growing at different rates, different smoke thickness, among other characteristics. As part of a validation study, participants were presented with subsets of the video clips and were asked to rate the perceived risk posed by the simulated fire.
    UNASSIGNED: We observed that ratings varied by the intensity and growth rate of the fires, smoke opacity, type of room, and where the viewpoint was located from the fire. These effects aligned with those observed in previous fire science research, providing evidence that the videos could elicit perceived risk using fire simulations. The present research indicates that future studies can utilize the video library of fire simulations to study human perceptions of developing building fires as situational factors are systematically manipulated.
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  • 文章类型: Journal Article
    通过将二元酸和氨基结构与氧化铈配位,成功合成了Ce基金属有机骨架(Ce-MOFs)。量子点尺度赋予Ce-MOFs增强的可改性性。此外,富含磷的生物质植酸,有许多羟基,加强系统内的H-bond网络。以Ce-MOFs为中心的纳米约束可以通过Ce-MOFs和聚乳酸(PLA)分子之间的多个H键相互作用形成,从而提高PLA的力学性能和阻燃性能。PLA/CeCxOy-P-3复合材料表现出优异的阻燃性和毒气抑制性能,峰值放热率降低27.8%,峰值产烟率降低50%。值得注意的是,与纯PLA样品相比,PLA/CeCxOy-P-3显示出低80%的峰值CO释放。此外,Ce-MOFs的掺入对PLA的拉伸性能有积极影响,把它从脆弱变成坚韧。这项工作在量子尺度上设计和合成了Ce-MOFs。具有预期结构的所得Ce-MOF为制备用于阻燃剂应用的MOF提供了新的方向。
    Ce-based metal-organic frameworks (Ce-MOFs) were successfully synthesized by coordinating binary acid and amino structures with cerium oxides. The quantum dot scale endows Ce-MOFs with enhanced modifiability. Additionally, the phosphorus-rich biomass phytic acid, with its numerous hydroxyl groups, strengthens the H-bond network within the system. Ce-MOFs-centered nanoconfinement can form through the multiple H-bond interactions between Ce-MOFs and polylactic acid (PLA) molecules, thereby improving the mechanical and flame-retardant properties of PLA. The PLA/CeCxOy-P-3 composite exhibited excellent fire retardancy and toxic gas suppression, with a 27.8% decrease in the peak heat release rate and a 50% reduction in the peak smoke production rate. Notably, PLA/CeCxOy-P-3 showed an 80% lower peak CO release compared with the pure PLA sample. Moreover, the incorporation of Ce-MOFs positively influenced the tensile properties of PLA, transforming it from brittle to tough. This work designed and synthesized Ce-MOFs on the quantum scale. The resulting Ce-MOFs with the anticipated structure offer a novel direction for preparing MOFs for flame retardant applications.
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  • 文章类型: Journal Article
    锂枝晶的不可控生长和电解质的可燃性是高能量密度锂金属电池(LMB)商业应用的直接障碍。在这里,这项研究提出了一种新颖的方法,结合微胶囊和静电纺丝技术来开发一种多功能复合隔膜(P@AS),以改善LMB的电化学性能和安全性能。P@AS分离器通过凝聚相阻燃机理形成致密的木炭层,导致内部分离器因缺氧而窒息。此外,它包含了促进锂离子均匀流动的三重策略,促进高离子传导性固体电解质界面(SEI)的形成,并通过活性SiO2种子点促进平坦的锂沉积,显著抑制锂枝晶生长。在具有无添加剂碳酸盐电解质的Li-Cu电池中实现了95.27%的高库仑效率。此外,在LFP//Li电池中300次循环后,还保持了稳定的循环性能,容量保持率为93.56%。重要的是,利用P@AS分离器将袋式电池在连续外部加热下的点火延迟138秒,导致峰值热释放率和总热释放量显著降低23.85%和27.61%,分别,大大提高了LMB的消防安全。
    The uncontrollable growth of lithium dendrites and the flammability of electrolytes are the direct impediments to the commercial application of high-energy-density lithium metal batteries (LMBs). Herein, this study presents a novel approach that combines microencapsulation and electrospinning technologies to develop a multifunctional composite separator (P@AS) for improving the electrochemical performance and safety performance of LMBs. The P@AS separator forms a dense charcoal layer through the condensed-phase flame retardant mechanism causing the internal separator to suffocate from lack of oxygen. Furthermore, it incorporates a triple strategy promoting the uniform flow of lithium ions, facilitating the formation of a highly ion-conducting solid electrolyte interface (SEI), and encouraging flattened lithium deposition with active SiO2 seed points, considerably suppressing lithium dendrites growth. The high Coulombic efficiency of 95.27% is achieved in Li-Cu cells with additive-free carbonate electrolyte. Additionally, stable cycling performance is also maintained with a capacity retention rate of 93.56% after 300 cycles in LFP//Li cells. Importantly, utilizing P@AS separator delays the ignition of pouch batteries under continuous external heating by 138 s, causing a remarkable reduction in peak heat release rate and total heat release by 23.85% and 27.61%, respectively, substantially improving the fire safety of LMBs.
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  • 文章类型: Journal Article
    尽管锂离子电池(LIBs)被广泛用作二次储能设备,它们还构成重大的火灾和爆炸危险。随后,LiPF6-和LiFSI-型电解质的热稳定性研究已经广泛进行。然而,在完整的电池组件中具有热稳定添加剂的这些电解质的热特性尚待探索。本研究提出了全面的加速速率量热法(ARC)研究。首先,使用对照商业LiPF6电解质和LiFSI以及特定的丁二腈添加剂和作为热稳定的电解质添加剂的碳酸乙酯-甲基酯制备1.2-Ah电池。从热等待搜索(HWS)分析了与热产生有关的动力学参数及其对ARC模块热性能的影响,自加热(SH),和热失控(TR)阶段。结果表明,在LiFSI电解质中添加丁二腈添加剂会降低固体电解质界面(SEI)的分解温度,这是由于在阳极与Li聚合,同时提高隔膜和电解质之间SEI反应温度的活化能。最大热失控温度从417°C(ΔH=5.26kJ)(LiPF6)降低到285°C(ΔH=2.068kJ)(LiFSI丁二腈)。这项研究为LiPF6和LiFSI在自加热和热失控阶段的热特性提供了关键见解,并指出了实现热稳定LIB的实用方法。
    Although lithium-ion batteries (LIBs) are extensively used as secondary storage energy devices, they also pose a significant fire and explosion hazard. Subsequently, thermal stability studies for LiPF6- and LiFSI-type electrolytes have been conducted extensively. However, the thermal characteristics of these electrolytes with thermally stable additives in a full cell assembly have yet to be explored. This study presents a comprehensive accelerating rate calorimetry (ARC) study. First, 1.2-Ah cells were prepared using a control commercial LiPF6 electrolyte and LiFSI with a specific succinonitrile additive and ethyl-methyl carbonate as a thermally stable electrolyte additive. The kinetic parameters involved in heat generation and their effects on the thermal properties of the ARC module were analyzed from the heat-wait-seek (HWS), self-heating (SH), and thermal runaway (TR) stages. The results indicate that the addition of a succinonitrile additive to the LiFSI electrolyte lowers the decomposition temperatures of the solid electrolyte interface (SEI) owing to polymerization with Li at the anode, while simultaneously increasing the activation energy of reaction temperatures at SEI between the separator and the electrolyte. The maximum thermal-runaway temperature decreased from 417 °C (ΔH = 5.26 kJ) (LiPF6) to 285 °C (ΔH = 2.068 kJ) (LiFSI + succinonitrile). This study provides key insights to the thermal characteristics of LiPF6 and LiFSI during the self-heating and thermal runaway stages and indicates a practical method for achieving thermally stable LIBs.
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  • 文章类型: Journal Article
    废物和生物燃料火灾事件在废物回收链的所有阶段都很常见,对企业产生严重影响,雇员,消防员,社会,和环境。在阴燃阶段及早发现废物和生物燃料火灾可以挽救宝贵的生命,资源,和我们的环境。现有的火灾检测方法,例如手持式温度传感器,红外照相机,气体传感器,视频和基于卫星的监测技术在有效检测阴燃火灾方面具有固有的局限性。尝试探索电阻率层析成像(ERT)作为解决该问题的替代工具的潜力。在实验中,使用外部供电的电阻线在测试材料(木屑颗粒,刨花,木罚款)。使用自动监测仪器设置记录了闷烧开始和发展后的ERT时间序列。将实验样品容器和电极设置的实际几何形状集成在3D有限元方法(FEM)模型网格中,以执行逆数值建模(反演)并开发电阻率断层图像。该研究表明,在闷烧热点区域的测试材料中,电阻率比率(R/Ro≥50%)急剧增加,并证明了ERT技术可用于检测筒仓和堆存有机材料的闷烧热点,例如木质燃料,木材废料,煤炭,城市固体废物(MSW),可回收物品等。然而,需要更多的研究来使这种技术能够在实际规模上用于不同的储存条件。
    Incidents of waste and biofuel fires are common at all stages of the waste recycling chain and have grave implications for business, employees, firefighters, society, and environment. An early detection of waste and biofuel fires in the smouldering stage could save precious lives, resources, and our environment. Existing fire detection methodologies e.g. handheld temperature sensors, IR cameras, gas sensors, and video and satellite-based monitoring techniques have inherent limitations to efficiently detect smouldering fires. An attempt was made to explore the potential of electrical resistivity tomography (ERT) as an alternate tool to address the problem. In the experiments an externally powered resistive wire was employed to initiate the smouldering fire inside the test material (wood pellets, wood shavings, wood fines). Time series of ERT that followed the initiation and development of smouldering were recorded using an automated monitoring instrument setup. The actual geometry of the experimental sample container and electrode setup was integrated in the 3D finite element method (FEM) model grid to perform inverse numerical modelling (inversion) and to develop resistivity tomographic images. The study shows a sharp increase in ratio of resistivity (R/Ro ≥ 50 %) in the test material in the region of smouldering hotspot and demonstrates the potential use of ERT technique for the detection of smouldering hotspots in silos and pile storage of organic material such as wood-based fuels, wood waste, coal, municipal solid waste (MSW), recyclables etc. More research is however required for enabling the use of this technique at the practical scale for different storage conditions.
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  • 文章类型: Journal Article
    为进行外科手术创造安全的环境对于实现成功的患者预后和保护提供护理的围手术期人员至关重要。许多因素挑战提供安全的护理环境,并为围手术期护士管理创造了复杂的环境。更新的AORN“安全护理环境指南”为围手术期护士提供了为患者和人员建立安全环境的建议。本文概述了该指南,并讨论了实施消防安全协议的建议,使用保温柜,创造一个乳胶安全的环境。它还包括一个场景,描述了正在接受腹腔镜袖状胃切除术和食管裂孔疝修补术的身份不明的乳胶过敏患者的护理。围手术期护士应全面审查指南,并实施适用于手术和其他程序环境的建议。
    Creating a safe environment for performing surgical procedures is essential to achieve successful patient outcomes and protect the perioperative personnel who are providing care. Numerous factors challenge the provision of a safe environment of care and create a complex setting for perioperative nurses to manage. The updated AORN \"Guideline for a safe environment of care\" provides perioperative nurses with recommendations for establishing a safe environment for both patients and personnel. This article provides an overview of the guideline and discusses recommendations for implementing fire safety protocols, using warming cabinets, and creating a latex-safe environment. It also includes a scenario describing the care of a patient with an unidentified latex allergy who is undergoing a laparoscopic sleeve gastrectomy and hiatal hernia repair. Perioperative nurses should review the guideline in its entirety and implement recommendations as applicable in operative and other procedural settings.
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  • 文章类型: Journal Article
    由于无处不在和取之不尽的太阳能,光热材料因其在加热和除冰方面的潜力而获得了相当大的关注。然而,传统的光热材料,以石墨烯为例,经常遇到的挑战,从他们的高反射率发出。受眼结构的启发,这项研究使用菲涅耳方程,通过引入聚二甲基硅氧烷(PDMS)/二氧化硅(SiO2)涂层来提高石墨烯的光热转换效率,通过破坏性干涉降低了光反射率(≈20%)。设计的涂层在一个太阳下达到约77°C的平衡温度,并在约65s内快速除冰,所有厚度为5µm。模拟表明,将这种涂层应用于高层建筑可在冬季供暖中节省约31%的能源。此外,PDMS/SiO2和石墨烯的组合通过协同阻燃机理赋予热稳定性显着增强,有效保护聚氨酯免受高温和火灾的影响,导致热量释放率和总热量释放分别降低58%和28%。这种创新的设计增强了光热转换,除冰功能,石墨烯的阻燃性,从而推进其在户外设备中的应用,高层建筑,和航空航天船。
    Due to the ubiquitous and inexhaustible solar source, photothermal materials have gained considerable attention for their potential in heating and de-icing. Nevertheless, traditional photothermal materials, exemplified by graphene, frequently encounter challenges emanating from their elevated reflectance. Inspired by ocular structures, this study uses the Fresnel equation to enhance the photo-thermal conversion efficiency of graphene by introducing a polydimethylsiloxane (PDMS)/silicon dioxide (SiO2) coating, which reduces the light reflectance (≈20%) through destructive interference. The designed coating achieves an equilibrium temperature of ≈77 °C at one sun and a quick de-icing in ≈65 s, all with a thickness of 5 µm. Simulations demonstrate that applying this coating to high-rise buildings results in energy savings of ≈31% in winter heating. Furthermore, the combination of PDMS/SiO2 and graphene confers a notable enhancement in thermal stability through a synergistic flame-retardant mechanism, effectively safeguarding polyurethane against high temperatures and conflagrations, leading to marked reduction of 58% and 28% in heat release rate and total heat release. This innovative design enhances the photo-thermal conversion, de-icing function, and flame retardancy of graphene, thereby advancing its applications in outdoor equipment, high-rise buildings, and aerospace vessels.
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  • 文章类型: Journal Article
    生物基官能化金属有机骨架(Bio-FUN-MOFs)由于其多途径阻燃机理和绿色合成过程而在阻燃领域的候选人群中脱颖而出。然而,探索和设计Bio-FUN-MOFs往往会抵消损害MOFs本身阻燃优势的问题,这不可避免地导致了资源的浪费。在这里,提出了一种通过酸碱平衡对MOFs进行生态调节的策略,用于由两只鸟用一块石头可控地制备Bio-FUN-MOFs,即,更高的阻燃元素负载和更多MOF结构的保留。具体来说,通过生物基碱精氨酸的弱蚀刻在ZIF-67的外围产生缓冲层,以抵抗负载磷源时植酸对ZIF-67的过度蚀刻,并尽可能保持内部晶体的完整性。作为概念的证明,在不存在精氨酸的情况下,ZIF-67几乎完全被植酸蚀刻掉。通过该策略获得的精氨酸和植酸官能化的具有卵黄@壳结构的ZIF-67(ZIF@Arg-Co-PA),作为一种生物基阻燃剂,降低聚脲复合材料的火灾危险。在只有5重量%的负载下,ZIF@Arg-Co-PA赋予聚脲复合材料的极限氧指数为23.2%,和热释放速率的峰值,总放热,烟气总量分别减少了43.8%,32.3%和34.3%,分别,与纯聚脲相比。此外,所制备的聚脲复合材料具有可接受的机械性能。这项工作将阐明具有出色防火安全性的聚合物复合材料的先进结构设计,特别是环保和高效的生物基MOF阻燃剂。
    Biobased-functionalized metal-organic frameworks (Bio-FUN-MOFs) stand out from the crowd of candidates in the flame-retardant field due to their multipathway flame-retardant mechanisms and green synthesis processes. However, exploring and designing Bio-FUN-MOFs tend to counteract the problem of compromising the flame-retardant advantages of MOFs themselves, which inevitably results in a waste of resources. Herein, a strategy in which MOFs are ecologically regulated through acid-base balance is presented for controllable preparation of Bio-FUN-MOFs by two birds with one stone, i.e., higher flame-retardant element loading and retention of more MOF structures. Specifically, the buffer layer is created on the periphery of ZIF-67 by weak etching of biobased alkali arginine to resist the excessive etching of ZIF-67 by phytic acid when loading phosphorus source and to preserve the integrity of internal crystals as much as possible. As a proof of concept, ZIF-67 was almost completely etched out by phytic acid in the absence of arginine. The arginine and phytic acid-functionalized ZIF-67 with yolk@shell structure (ZIF@Arg-Co-PA) obtained by this strategy, as a biobased flame retardant, reduces fire hazards for polyurea composites. At only 5 wt % loading, ZIF@Arg-Co-PA imparted polyurea composites with a limiting oxygen index of 23.2%, and the peaks of heat release rate, total heat release, and total smoke production were reduced by 43.8, 32.3, and 34.3%, respectively, compared to neat polyurea. Additionally, the prepared polyurea composites have acceptable mechanical properties. This work will shed light on the advanced structural design of polymer composites with excellent fire safety, especially environmentally friendly and efficient biobased MOF flame retardants.
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  • 文章类型: Journal Article
    Insulation products made of expanded polystyrene (EPS) are commonly utilized in buildings. However, Norwegian building regulations restrict the use of such combustible insulation due to an increased risk of fire spread and generation of smoke and toxic gases. Installation of fire protection coverings has been adopted as a mitigation strategy to address these safety risks. Notably, the current regulations lack pre-approved solutions describing what is considered an adequate protection of combustible insulation. The present study investigated the fire protection properties of selected coverings used to protect EPS insulation in inner walls. Eight comparative fire tests were conducted using an indicative fire resistance test furnace. The test specimens consisted of EPS blocks mounted on a wooden frame and covered with one or two layers of selected board coverings. The specimens were positioned vertically within the test furnace, and each fire test lasted for 10 or 15 min. Test results revealed that only two configurations consisting of either two layers of 12.5 mm gypsum boards or a combination of 12 mm oriented strand board (OSB) and 12.5 mm gypsum board showed no evidence of damage to the EPS substrate after a 15-min fire exposure. Consequently, the findings suggest that a total covering thickness of at least 24.5 mm, comprising two layers of boards, is necessary to prevent adverse effects on EPS insulation. Furthermore, fire tests conducted on coverings with introduced damages and defects showed that the affected area around the damages and defects were limited. For the standard EPS substrate, this area extended from 28 mm to 90 mm, while for the fire-retardant EPS substrate from 28 mm to 75 mm after a 10-min fire exposure. These results suggest that minor physical failures in the covering have limited impact on the fire safety of the system.
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  • 文章类型: Journal Article
    随着可持续发展战略的提出,生物基储能透明木材(TW)在绿色建筑中显示出广泛的应用价值,冷链运输,和光电器件领域。然而,由于其自身的可燃性,其在大多数领域的应用受到限制。在这项研究中,环氧树脂,通过真空压力浸渍将磷酸三乙酯(TEP)和聚乙二醇(PEG)引入去木素轻木木模板中,和生物基TW/PEG/TEP集成阻燃剂,制备了高强度和相变储能性能。TW/PEG复合材料在相变过程中没有泄漏,其透明度高达95%。与TW/PEG相比,炭层的屏蔽作用和冷凝相和气相的抑制作用显着降低了TW/PEG/TEP的总放热。TW/PEG/TEP生物复合材料仍保持了较高的相变焓和较低的峰值熔化温度,有利于其在低温相变储能领域的应用。此外,TW/PEG/TEP的拉伸强度是DW的近4倍,韧性明显增强。TW/PEG/TEP生物复合材料符合当前的节能和绿色发展理念。具有替代传统石化基材料的潜力,在新兴领域显示出优异的应用前景。
    With the proposal of sustainable development strategy, bio-based energy storage transparent wood (TW) has shown broad application value in green buildings, cold chain transportation, and optoelectronic device fields. However, its application in most fields is limited due to its own flammability. In this study, epoxy resin, triethyl phosphate (TEP) and polyethylene glycol (PEG) were introduced into delignified balsa wood template by vacuum pressure impregnation, and bio-based TW/PEG/TEP integrating flame retardant, high strength and phase-change energy-storage performance was prepared. TW/PEG composites have no leakage during phase change process and their transparency is up to 95 %. Compared with TW/PEG, the shielding effect of char layer and the inhibition effect in condensed and gas phase significantly decrease the total heat release of TW/PEG/TEP. TW/PEG/TEP biocomposites still maintained a high enthalpy of phase change and a low peak melting temperature, which was conducive to its application around the area of low temperature phase change energy storage. In addition, the tensile strength of TW/PEG/TEP was nearly 4 times higher than that of DW, and its toughness was obviously enhanced. TW/PEG/TEP biocomposites conformed to the current concept of energy-saving and green development. It has the potential to replace traditional petrochemical-based materials and shows excellent application prospects in emerging fields.
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