Search Results (545)

Polymeric materials face serious fire-safety challenges in construction, electrical and electronic devices, and aerospace because of their high heat release, melt-dripping tendency, and severe smoke and toxic emissions during burning. This review systematically summarizes the roles of nanofillers in the fire safety of polymer nanocomposites across three interconnected levels: functional mechanisms, regulatory factors, and macroscopic fire behavior. It focuses on four main mechanisms, namely physical barriers, catalytic charring, free-radical scavenging, and rheological network reconstruction, and further discusses how filler geometry, loading level, interfacial compatibility, dispersion state, and spatial orientation regulate fire-safety performance. By linking these factors to time to ignition, thermal stability, heat release, flame spread, and smoke emission and toxicity, the review clarifies the intrinsic structure–mechanism–property relationships. Current studies indicate that the fire-safety improvements provided by nanofillers do not arise from any single effect, but from their coupled regulation of heat transfer, mass transfer, radical reactions, and high-temperature rheology throughout thermal degradation, ignition, heat release, flame spread, and smoke and toxic-gas emission. Remaining challenges include the lack of unified evaluation criteria, limited in situ mechanistic evidence, and insufficient application-oriented rational design. Future work should establish verifiable, comparable, and predictive structure–mechanism–property relationships for polymer nanocomposites. Full article

In this study, a new approach to improving the fire resistance of flexible polyurethane (PUR) foams is presented, based on the incorporation of cotton chemically modified with boron compounds into the polyurethane matrix. The developed system was additionally modified with melamine polyphosphate (MPP). The effects of the applied modifications on the morphology and chemical structure of the PUR composites were investigated using scanning electron microscopy and infrared spectroscopy. Thermal stability was evaluated by thermogravimetric analysis, whereas fire hazard was assessed using cone calorimetry and a smoke optical density chamber. The toxicometric index (WLC_50SM) was determined using a coupled TG-Omega 5 gas analyzer system. The results provide insight into the mechanism responsible for reducing flammability and limiting the emission of toxic combustion and thermal decomposition products through the modification of PUR foams with chemically modified cotton in combination with MPP. It was observed that, during the combustion of the developed PUR composites, the addition of cotton promotes the formation of a three-dimensional spatial network, which substantially limits heat release and the emission of toxic combustion products. Consequently, the composites exhibited a reduction in heat release of up to 67% in terms of HRR_MAX, together with decreased production of HCN and CO. Nevertheless, the formation of a protective carbon layer contributed to an increase in smoke optical density, which was associated with increased CO₂ emission. Overall, this work demonstrates the development of a new synergistic system capable of reducing both the flammability and toxicity of flexible PUR foams. Full article

The carriage of portable electronic devices (PED) powered by lithium-ion batteries in the aircraft cabin today is a fact. Passengers carry several such batteries in mobile phones, tablets, laptops, e-cigarettes, power banks, etc. Even though rare, there is a remaining risk that a Li-ion battery experiences thermal runaway. This typically results in the emission of smoke and gas as well as the emergence of flames and fire, thus posing a threat to safe operation. To meet this challenge, procedures have been defined, and additional mitigation means have emerged on the market. This study presents an anonymized assessment of additional mitigation means. For this, manufacturers provided samples of their product on a voluntary basis to test the potential to contain a Li-ion battery fire. Furthermore, handling was evaluated by a panel of cabin crew members. As a result, a series of recommendations for additional mitigation means and procedures was derived. Full article

Passengers routinely carry numerous Portable Electronic Devices (PEDs) powered by lithium-ion batteries, which present hazards when subjected to thermal runaway, including emission of toxic gases, smoke generation and potential fires. The LOKI-PED project investigates the severity of such events in aircraft cabins by experimentally characterizing combustion gases, validating a zonal cabin model and predicting exposure to harmful substances and smoke. PEDs were deliberately forced into thermal runaway in both burn chamber and A320 cabin mockup tests, enabling the quantification of emitted carbon dioxide and toxic compounds such as carbon monoxide, formaldehyde, hydrogen fluoride, and hydrogen chloride. These measurements were correlated to CO₂ peak concentrations, enabling a factor-based scaling approach for full-scale cabin simulations. A validated zonal model was then used to predict the temporal and spatial spread of gases and smoke in the cabin, cockpit and galley. Results show that while cabin ventilation generally keeps exposure below harmful levels, the cockpit and galley are significantly more vulnerable. The study highlights the importance of rapid crew response, limitations on PED battery capacities and operational mitigation strategies to ensure flight safety. Full article

This study investigates long-term wildfire emissions and smoke-plume geospatial characteristics in Greece by analyzing a multi-pollutant dataset spanning January 2003 to August 2025. Details of emissions of carbon monoxide (CO), carbon dioxide (CO₂), methane (CH₄), particulate matter (PM_2.5), organic carbon (OC), and black carbon (BC) were derived from the Global Fire Assimilation System (GFAS), which converts MODIS fire radiative power into trace gas and aerosol fluxes at 0.1° resolution, and also accounts for the land type. Burned-area statistics from the European Forest Fire Information System (EFFIS) were used for cross-validation. Data were processed into daily, monthly, annual, and cumulative time series, with spatial mapping at the municipality scale and information regarding long-term trends. The analysis shows that while there are several sizeable wildfire events in the country every year, the bulk of the total of Greek wildfire emissions for the last 23 years is attributable to a few extreme fire seasons (2007, 2021, and 2023) that produced abrupt emission surges and accounted for a disproportionate share of national totals. Analysis of spatial data identifies the areas of Evia, East Attica, Messinia, and Evros as persistent emission hotspots. Although wildfire CO₂ emissions are generally a minor fraction of Greece’s anthropogenic totals (<5%), they reached 15–17% during peak fire years. Plume-injection height analysis reveals that most smoke remains below ~1 km but can reach 3–6 km during extreme events, facilitating long-range transport. Overall, the dataset demonstrates a shift toward more intense and concentrated wildfire events in recent years, highlighting both their growing climatic relevance and their acute impacts on regional air quality. Full article

We co-modified layered double hydroxide (LDH) in water using phosphocreatine (PC) and dodecylphosphoric acid (DPA) to obtain a highly dispersible LDH. Embedding this LDH in epoxy enabled V-0 at 7 wt% and lowered HRR, THR and TSP, attributed to a dense char and PC-DPA synergy. SEM, WAXS, and TGA characterised the structure and thermal behaviour of the functionalised LDHs. These modified LDHs were then loaded into the epoxy resin (EP) to develop flame-retardant nanocomposites. Compared to unmodified LDH (NO₃-LDH) and PC-modified LDH (PC-LDH), PC-DPA-LDH showed superior dispersion and compatibility within the epoxy matrix. As a result, PC-DPA-LDH/EP achieved a UL-94 V-0 rating at only 7 wt% loading, while NO₃-LDH/EP had no rating, and PC-LDH/EP reached only V-2. Moreover, PC-DPA-LDH/EP demonstrated significant decreases in peak heat release rate (46.4%), total heat release (34.5%), and total smoke production (59.7%) compared with neat EP. These improvements were attributed to the synergistic flame-retardant effects of PC and DPA, as well as to the formation of a compact char layer that effectively insulated the underlying material and suppressed volatile emissions. This work highlights the potential of bio-based, aqueous-synthesised nanohybrids for high-efficiency, eco-friendly flame-retardant epoxy systems. Full article

Background: Low-dose CT scanning is a key tool in lung cancer screening, enabling the detection of clinically significant abnormalities in asymptomatic individuals and often prompting further diagnostic evaluation. Case Presentation: We describe the case of an 80-year-old man with a heavy smoking history who was found to have a new right middle lobe collapse on screening CT. Subsequent positron emission tomography-computed tomography (PET/CT) imaging demonstrated mild fluorodeoxyglucose (FDG) uptake (SUVmax 2.7), raising concern for a low-grade endobronchial malignancy versus mucoid impaction. Flexible fiberoptic bronchoscopy revealed a large exophytic endobronchial mass occluding the airway. Histopathologic examination of the biopsy sample unexpectedly revealed vegetable material, consistent with chronic foreign-body aspiration. Discussion: Unrecognized aspiration events are relatively common in elderly adults and can mimic malignancy on imaging. This case highlights an important diagnostic pitfall: inflammatory endobronchial processes, including foreign-body granulomas, can demonstrate FDG uptake and mimic malignancy. Conclusion: Clinicians should maintain a broad differential diagnosis when evaluating PET-avid endobronchial lesions, especially in elderly patients. Full article

Smoking is a major lifestyle factor associated with impaired male reproductive health, affecting both active smokers and individuals exposed to secondhand smoke. It also represents a significant source of cadmium (Cd) exposure, a toxic metal associated with altered sperm quality. This study aimed to evaluate the association between active and passive smoking and semen parameters, sperm DNA fragmentation, and chromatin decondensation, as well as cadmium (Cd) and zinc (Zn) levels in seminal plasma. A total of 280 men from infertile couples were included and categorized into three groups: 104 non-smokers (control), 90 active smokers, and 86 passive smokers. Semen samples were analyzed according to the WHO 2021 guidelines. Cadmium and zinc concentrations in seminal plasma were determined using inductively coupled plasma atomic emission spectroscopy (ICP-AES), and sperm DNA fragmentation and chromatin decondensation were evaluated. The findings indicated that both active and passive smoking were associated with impaired semen parameters, increased sperm DNA fragmentation and chromatin decondensation, decreased zinc levels, and elevated cadmium concentrations in seminal plasma. Full article

This research evaluated the efficacy of using two types of biochar (non-modified and acidified) from date palm residues (fronds, leaves, pits) as soil amendments for enhancing soil fertility and maize growth. These biochars were produced through slow pyrolysis under oxygen-limited conditions at 500 °C. Our innovative approach was to minimize gas emissions by converting smoke into liquid fertilizer (LS), which was expected to improve seed germination and early plant growth stages. To assess this aim, a completely randomized experiment was conducted under lab conditions, in which 10 maize seeds were placed on double filter papers in Petri dishes and then exposed to seven concentrations of LS (0.0, 0.01, 0.10, 1.0, 10 and 100%, using distilled water for dilution v/v). The LS contains nutrients and bioactive compounds that may enhance seed germination and early plant growth at low concentrations, whereas higher concentrations may cause phytotoxic effects. Results showed that liquefied smoke at 0.1% increased the absolute percentage of maize germination from 75% (control) to 100% and achieved the highest root length of 9.80 cm. Acidified biochars at 5% reduced soil pH from 8.87 to 8.12 and enhanced potassium availability to 87.93 mg kg⁻¹. Conversely, the non-modified biochars contributed to further increases in soil organic matter (up to 1.02%), nitrogen, and phosphorus. In addition, the application of acidified leaf biochar (5%) enhanced maize shoot growth by 133%, chlorophyll content by 39%, and potassium uptake by 110%. This research establishes a scalable approach for converting agricultural waste into climate-resilient resources, effectively addressing soil degradation in arid environments, boosting crop resilience, and furthering the objectives of a circular bioeconomy. Full article

Liquefied petroleum gas (LPG) is a widely available alternative fuel, easily stored in liquid form, capable of displacing diesel fuel in compression-ignition engines. Bio-LPG extends this pathway because it is a renewable drop-in form of LPG; its distinguishing advantage is not a different in-cylinder combustion chemistry, but a lower life-cycle greenhouse-gas intensity that depends on feedstock and production route. This review, therefore, combines a systematic synthesis of CI-engine LPG combustion evidence with a Bio-LPG transition perspective. A PRISMA-guided search of major databases (2000–2025) yielded 47 studies with matched diesel baseline. Evidence was categorized by LPG utilization pathway, distinguishing between fumigation, gaseous port injection, and in-cylinder LPG direct injection (gaseous or liquid), alongside engine class, pilot fuel fraction, and key operating parameters (injection timing/quantity, intake conditioning, exhaust gas recirculation (EGR), and boost). Data were normalized as percentage deviations relative to diesel and synthesized across standardized load bins (25/50/75/100%). Among studies reporting nitrogen oxides (NO_x), 20 of 37 showed net reductions, while results in 12 studies were load-dependent; particulate matter (PM), smoke, and soot indicators decreased in 17 of 27 cases. While intake-path strategies generally reduced NO_x and smoke, they often increased CO and HC emissions at low loads. The limited emerging liquid-phase direct-injection evidence shows the closest diesel-like efficiency response, although the evidence base remains limited. Overall, the engine-level findings identify the most promising LPG/Bio-LPG deployment pathways, while the specific additional climate benefit of Bio-LPG lies in its lower well-to-wheel greenhouse-gas intensity. Full article

The decarbonization of marine transport requires the wider use of alternative low-carbon fuels that can be applied in existing compression ignition (CI) engines without major modifications. Hydrotreated vegetable oil (HVO) is considered a promising renewable drop-in fuel due to its favorable physicochemical properties and high cetane number. This study investigates the influence of neat HVO and its blends with conventional diesel fuel on the combustion characteristics, energy, and emission indicators of a CI engine operating under different load conditions and exhaust gas recirculation (EGR) ratios. Experimental tests were carried out on a four-cylinder CI engine at constant speed and variable load using diesel fuel (D100), HVO100, and their blends (D80_HVO20 and D50_HVO50). In-cylinder pressure measurements and combustion analysis were performed using AVL instrumentation and AVL BOOST software. The results show that increasing the HVO fraction slightly advances combustion phasing and increases maximum in-cylinder pressure by approximately 4–5%. The use of HVO was found to reduce brake-specific fuel consumption by up to 3.4% and increase brake thermal efficiency by about 1.9%, although volumetric fuel consumption increases due to the lower fuel density. In addition, higher HVO content significantly reduces smoke opacity by up to 42% and decreases CO₂ emissions by 4.7–6.3%, while the influence on NO_x emissions depends on the applied EGR strategy. The results indicate that HVO and its blends can be effectively applied in CI engines; however, optimal performance and emission characteristics require appropriate calibration of EGR rate and fuel injection timing. Full article

Background: Manganese (Mn) is an essential trace element with antioxidant properties; however, excessive exposure may contribute to inflammation and vascular dysfunction. Hair analysis provides an indicator of long-term Mn exposure. This study evaluated the relationship between hair Mn levels, acute coronary syndrome (ACS), coronary artery disease (CAD) severity, and cardiovascular risk factors, with particular emphasis on metabolic status in a cardiometabolic population. Methods: Hair Mn concentration was measured using inductively coupled plasma optical emission spectrometry (ICP-OES) in 80 patients (mean age 67 ± 11 years; 28.8% women) undergoing coronary angiography for suspected ACS. Final diagnoses included stable CAD (N = 42) and ACS [ST-elevation myocardial infarction (STEMI) N = 17, non-ST-elevation myocardial infarction (NSTEMI) N = 12, and unstable angina (UA) N = 9]. CAD severity was quantified using the SYNTAX score and the Coronary Artery Surgery Study Score (CASSS). Associations with clinical variables were assessed using non-parametric tests and Spearman correlations. The median SYNTAX score was 13.8 (range 0.0–68.5), and the median hair Mn concentration was 0.22 ppm (range 0.01–1.65). Results: SYNTAX scores were higher in ACS than in stable CAD (p = 0.027), with the highest values observed in NSTEMI. Hair Mn levels did not differ among diagnostic groups and showed no association with CASSS or SYNTAX (R = −0.11; p = 0.348). No differences were detected with respect to sex, smoking, prior myocardial infarction, hypertension, hyperlipidemia, or type 2 diabetes. A modest inverse correlation was observed between hair Mn and body mass index (BMI) in unadjusted analysis (R = −0.25; p = 0.03), but this association was not robust after correction for multiple comparisons, suggesting a potential exploratory link between manganese homeostasis and cardiometabolic status. Conclusions: Although hair Mn concentration was not associated with angiographic indices of CAD severity or ACS subtypes, the observed relationship with BMI may indicate a role of Mn homeostasis in cardiometabolic regulation. Larger prospective studies are required to clarify these associations. Full article

Background/Objectives: Endometrial cancer (EC) is a multifactorial disease influenced by metabolic, hormonal, and environmental factors. Trace and macroelements play a critical role in cellular homeostasis, oxidative stress, and tumor progression; however, their relationship with EC grading and clinical characteristics remains insufficiently understood. Methods: This study evaluated the concentrations of selected macro- and trace elements (Na, K, Ca, P, Mg, Mn, Cu, Zn, Be, As, Cr, Mo, Ti, Tl, Pb) in patients with endometrial cancer (G1–G3) and a control group (C). Elemental analysis was performed using inductively coupled plasma optical emission spectrometry (ICP-OES). Associations between elemental concentrations and clinicopathological variables, including age, body mass index (BMI), menopausal status, diabetes, and smoking, were assessed using appropriate statistical tests, including ANOVA with Tukey’s post hoc analysis and Student’s t-test. Multivariate regression analysis was performed to identify independent predictors of elemental alterations. Results: Significant differences in elemental concentrations were observed across EC grading. Higher-grade tumors were associated with increased levels of Ca, P, Mg, and Mn, while Na and K showed a decreasing trend with tumor progression. No statistically significant differences were observed for Zn, Ti, Tl, or Pb across histological grades. Stratified analyses demonstrated that clinical and metabolic factors had a limited and selective impact on elemental profiles. Age and BMI were associated with minor variations in selected elements, whereas menopausal status, diabetes, and smoking showed predominantly non-significant or inconsistent effects. Multivariate analysis identified histological grade as the primary determinant of elemental alterations, while other variables exhibited weaker or element-specific associations. Conclusions: Elemental homeostasis in endometrial cancer is primarily associated with tumor progression rather than systemic metabolic or lifestyle factors. Changes in Ca-, P-, Mg-, and Mn-related pathways may reflect tumor-driven metabolic reprogramming, whereas most trace elements remain relatively stable. These findings suggest that elemental profiling may provide insight into EC biology, although its clinical utility requires further investigation. Full article

We assess associations between emergency room (ER) visits, scaled to per 10⁵ population per year, for asthma and chronic obstructive pulmonary disease (COPD), two of the most common respiratory diseases, and zip code-level exposure to criteria air pollutants (CAPs) coming from point sources in New York State (NYS) from 2010 to 2018. Exposure data on point source CAPs were retrieved from the United States Environmental Protection Agency (USEPA) National Emission Inventory (NEI) database, and ER visits for asthma and COPD were acquired from the New York State Department of Health (NYSDOH) Statewide Planning and Research Cooperative System (SPARCS). To account for within-county variability, we used log-linear mixed effects models, adjusted for year, sex, age category, county-level poverty, smoking, PM_2.5, volatile organic compounds (VOCs), and CAPs sources within the study period. Results show significant associations between ER visits for asthma and COPD and most of the pollutants in the study, even after adjusting for the effects of poverty and smoking. Although point source emissions comprise a small portion of total air pollution, our findings show that zip code-level point source CAPs, especially the gaseous pollutants, pose a modest but significant contribution to the risk of respiratory disease-related ER visits. Full article

This study explores the viability of condensate petroleum, an ultra-light hydrocarbon derived from natural gas production, as an alternative diesel engine fuel. The researchers tested six different fuel blends, increasing the condensate volume by 10% increments, in a compression ignition engine under three distinct load conditions (25%, 50%, and 75%) to evaluate both combustion characteristics and emission performance. The results demonstrate that condensate blends significantly enhance key combustion parameters. The heat release rate, in-cylinder pressure, and in-cylinder temperature all increased, with the highest heat release rate improvement of 35.6% observed at a 75% load using a 60% condensate petroleum blend. However, increasing the condensate ratio also extended ignition delay times and raised the ringing intensity, which peaked with a 34.7% increase at a 25% load. Brake thermal efficiency improved at lower and medium loads—achieving a maximum 11.2% increase with the 50% condensate petroleum blend at 50% load—but decreased when the engine reached 75% load. In terms of environmental impact, the condensate blends proved largely beneficial. Carbon monoxide emissions dropped by 57.9% (at 75% load, 60% condensate petroleum), smoke opacity decreased by 72.6% (at 25% load, 40% condensate petroleum), and hydrocarbons fell by 34.4% (at 50% load, 60% condensate petroleum). The primary drawback was that nitrogen oxide emissions worsened, increasing by 20.4% at 75% load with the 50% condensate petroleum blend. Overall, the study concludes that the effects of condensate petroleum are highly acceptable, making it a promising alternative fuel and additive for diesel engines. Full article