Global Impact Journal: Fire, Safety & Risk Management

Study on the Effect of Modified Vanadium–Titanium Slag Explosion Suppressant on the Explosion Characteristics of Polyacrylonitrile Dust

2026-08-27T11:00:33+00:00

In this study, a composite powder explosion suppressant (MVTS–NaHCO₃) was prepared via the wet coating method of the solution–crystallization (WCSC) process, using modified vanadium–titanium slag (VTS) as the carrier and NaHCO₃ as the active suppressive component. A 20 L spherical explosion apparatus and a transparent pipeline explosion propagation test system were employed to investigate the effects of the composite powder explosion suppressant with different mass fractions (0%, 10%, 20%, 30%, 40%, 50%) on the explosion pressure and micro-mechanism of polyacrylonitrile (PAN) dust. The experimental results indicated that the MVTS–NaHCO₃ composite powder exhibited a significant suppression effect on PAN dust explosions. In the confined 20 L vessel, complete suppression was achieved when the mass fraction of the composite powder explosion suppressant exceeded 30%, with a maximum explosion pressure reduction of 53.2%. In the semi-open pipeline, 40% composite powder explosion suppressant reduced the maximum explosion pressure to 0.08 MPa (a reduction rate of 82.6%), and complete suppression was achieved at a mass fraction of 50%. Microstructural analysis revealed that the suppression performance of the composite powder explosion suppressant is attributed to the synergetic effects of physical and chemical mechanisms. Physically, NaHCO₃ decomposes endothermically (100 kJ/mol), releasing CO₂ and H₂O and thereby diluting the oxygen concentration, while the porous structure of MVTS enhances dispersibility. Chemically, the hydroxyl groups on the surface of MVTS bond with NaHCO₃, delaying its decomposition, while metal hydroxides (e.g., Al(OH)₃) decompose thermally to form Al₂O3, which adsorbs and quenches free radicals (e.g., ·OH, ·H), thereby inhibiting chain reactions. This study provides new insights for the resource utilization of VTS and the prevention and control of industrial dust explosions. The findings have important reference value for optimizing explosion suppressant formulations and improving the intrinsic safety.

A Decision Indicator System for Takeoff and Landing Site Selection of Bucket Firefighting Helicopters in Wildfire Emergency Response

2026-05-19T11:40:57+00:00

With the increasing complexity of wildfire emergency response, the aerial emergency response system is imposing increasing demands on both safety and decision rationality of takeoff and landing site selection. Site selection decisions are influenced by multi-dimensional factors, including geographical location, meteorological factors, and operational safety considerations, resulting in a pronounced coupling of multiple factors in the decision-making process. However, existing studies primarily focus on spatial suitability evaluation or technical implementation, often relying on predefined indicator systems and independence assumptions, while lacking a systematic characterization of the influencing factor system and its interrelationships in takeoff and landing site selection. To address this gap, this study proposes a novel structured decision-making framework to systematically analyze and optimize the selection of takeoff and landing sites for bucket firefighting helicopters in wildfire aerial emergency
response scenarios. First, a procedural grounded theory approach is employed to systematically identify the influencing factors associated with site selection, thereby constructing a traceable decision-making factor system. Second, fuzzy DEMATEL is applied to model the causal relationships and structural interdependencies among these factors. Finally, a cumulative contribution rate based on centrality is introduced to screen and optimize the decision indicators, resulting in a refined set of key decision indicators. The results reveal the structural roles of different influencing factors in site selection, reduce the reliance on experience-driven judgment, and reconceptualize the problem from traditional indicator weighting and ranking into a structured decision-making process involving multi-factor coupling. This provides systematic decision support for takeoff and landing site selection in wildfire aerial emergency response and establishes a foundation for subsequent spatial suitability analysis and case-based validation. Furthermore, the results are consistent with expert experience and practical operational constraints, indicating the potential applicability of the proposed method in real-world decision-making.

Inter Layer Effect of Poly(acrylic acid) on the Multilayers Assembly on Cotton Fabric Using Bentonite/Halloysite/Chitosan Composite Matrix

2026-08-27T11:09:43+00:00

In this work, poly(acrylic acid)-based layers were injected to form a sandwich layer between the cationic and anionic species for a compact and effective fire-retardant coating on cotton fabric using the layer-by-layer coating technique. From the SEM analysis, as the number of tri-layers increases, the attachment intensity increases, as can be seen for poly(acrylic acid) chitosan and bentonite clay PCB-5TL (the highest tri-layers), while in the case of halloysite-based coatings, as the number of tri-layers increases, instead of attachment, the agglomeration increases due to the high surface area of halloysite nanoclay tubes. FTIR and UV confirmed the finding from the new peak entry and an increase in thickness. The highest thermal residue, approx. 18%, was obtained for poly(acrylic acid) chitosan and halloysite nanoclay PCH-5TL with a maximum degradation peak intensity at approx. 389 ^◦C. From the flammability and after-burning SEM investigation test, it was observed that the halloysite-based coating with a higher number of layers offered higher resistance against the flame spread and ignition and, thus, produced a higher amount of char.

Reframing Data Center Fire Safety as a Socio-Technical Reliability System: A Systematic Review

2026-08-06T05:59:52+00:00

Data centers are critical digital infrastructure supporting cloud computing, artificial intelligence, and global information services. Despite their high-reliability design, they remain vulnerable to fire incidents due to continuous operation, high electrical loads, dense power systems, and the increasing use of lithium-ion batteries. Although such events are rare, their consequences can be severe, including service disruption, equipment damage, financial loss, and risks to data integrity. This study presents a systematic literature review of fire safety risk management frameworks in data centers, following PRISMA guidelines. Peer-reviewed studies published between 2020 and 2025 were retrieved from Scopus and Web of Science, screened, and appraised using structured quality criteria. Twelve empirical studies were synthesized and benchmarked against NFPA 75 and NFPA 76 standards. The findings are organized into three domains: Strategic Management, Fire Risk, and Fire Preparedness. The results show a strong focus on technical prevention and electrical hazards, while organizational readiness, emergency response, and recovery remain underexplored. Benchmarking indicates that industry standards adopt a more comprehensive lifecycle approach than the academic literature. This study reframes data center fire safety as a socio-technical reliability system and highlights critical gaps, providing a foundation for future research and improved fire safety governance and resilience.

Field-Based Fitness Tests Predict Completion of a Firefighter Recruit Academy

2026-08-27T11:20:48+00:00

Recruitment of firefighters is, in part, hindered due to attrition from fire academies. This study explored initial fitness differences between those who graduated (GRAD) or were released (REL) from the academy. During the first week of the academy, recruits (N = 407; GRAD = 354, REL = 53; 26.6 ± 7.2 yrs; 177.6 ± 8.6 cm; 87.9 ± 17.2 kg) completed an assessment battery including: body composition using skinfold calipers to estimate percent body fat (BF) and fat-free mass (FFM); shoulder mobility via Apley’s scratch test (APLEY); aerobic fitness (VO_2peak) and heart rate recovery (HRR_1min) estimated from the five-minute Forestry step test; muscular strength via the sum of right and left handgrip (SHG); and muscular endurance via a paced two-minute push-up test (PU). A t-test identified age differences between GRAD and REL, followed by separate ANCOVAs for each fitness measure, and logistic regression to identify the ability of fitness measures to predict academy outcome. GRAD had a lower age and BF and a higher FFM, VO_2peak, SHG, and PU, but did not differ in APLEY or HRR_1min. The full model predicting release was significant; age, BF, and FFM were significant predictors. These results provide pre-fire academy preparation guidance for optimizing the potential for successful academy completion.