Search Results (133)

Point-type smoke fire detectors have become one of the most commonly used technical means in the fire detection systems of ancient buildings. However, in practical applications, their performance is easily affected by special environmental interference factors. Therefore, in this study, a full-scale experimental scene of an ancient building with a typical flush gable roof structure was taken as the research object, and the differential influence laws of three typical interference sources, namely wind speed, water vapor, and incense burning, on the response times of point-type smoke detectors were quantified. Moreover, the prediction models of the alarm time of the detectors under the three interference conditions were established. The results indicate the following: (1) Within the range of experimental conditions, there is a quantitative relationship between the detector response delay and the type of interference source: the delay time shows a nonlinear positive correlation with the wind speed/water vapor interference gradient, while it exhibits a threshold unimodal change characteristic with the burning incense interference gradient; (2) under interference conditions, the detector response delay varies depending on the type of fire source: the detector has the best detection stability for smoldering smoke from a smoke cake, while it has the lowest detection sensitivity for smoldering smoke from a cotton rope. Moreover, the influence of wind speed interference is weaker than that of water vapor or smoke from burning incense, and the difference is the greatest in the wood block smoldering condition. (3) Construct a detector alarm time prediction model under three types of interference conditions, where the wind speed, water vapor, and burning incense interference conditions conform to third-order polynomial functions, Sigmoid functions, and fourth-order polynomial functions, respectively. Full article

The movement towards low-emission and sustainable building practices has driven increased use of natural, carbon-based materials such as wood. While these materials offer significant environmental advantages, their inherent flammability introduces new challenges for timber building safety. Despite advancements in fire protection standards and building regulations, the risk of fire incidents—whether from technical failure, human error, or intentional acts—remains. The rapid detection of fire onset is crucial for safeguarding human life, animal welfare, and valuable assets. This study investigates the potential of monitoring fire precursor gases emitted inside building structures during pre-ignition and early combustion stages. The research also examines the sensitivity and effectiveness of commercial smoke detectors compared with custom sensor arrays in detecting these emissions. A representative structural sample was constructed and subjected to a controlled fire scenario in a laboratory setting, providing insights into the integration of gas sensing technologies for enhanced fire resilience in sustainable building systems. Full article

Background: Chronic Obstructive Pulmonary Disease (COPD) exhibits some phenotypic differences between patients with biomass smoke inhalation (COPD-B) and tobacco smoking (COPD-T). COPD-B is characterized by less emphysema but more airway disease and vascular pulmonary remodeling, which are related to mast cells in lung tissues in COPD-T. Our objective was to describe the differences between the number of mast cells in COPD-B and COPD-T patients. Methods: A cross-sectional study was conducted on lung tissue resections for suspected cancer obtained between 2014 and 2021 from patients with documented COPD due to wood smoke or tobacco exposure. Histological samples were analyzed for mast cell count, CD34+ expression, and structural changes in lung tissue and pulmonary circulation. Results: A total of 20 histological samples were analyzed, with significant differences found in mast cell count [median 8 (p25-75, 5–11) vs. 2 (p75-25, 0–6), p = 0.016] and severe peribronchiolar fibrosis (60% vs. 10%, p = 0.04) between COPD-B and COPD-T patients. A positive correlation [Spearman rho = 0.879 (95% CI 0.71–0.96), p < 0.001] was observed between mast cell count and a gradual increase in pulmonary artery diameter. Conclusions: These preliminary findings suggest histological differences and the presence of mast cells between COPD-B and COPD-T, which should be confirmed in a larger number of samples and patients. Full article

Fire-resistant coatings have emerged as crucial materials for reducing fire hazards in various industries, including construction, textiles, electronics, and aerospace. This review provides a comprehensive account of recent advances in fire-resistant coatings, emphasizing environmentally friendly and high-performance systems. Beginning with a classification of traditional halogenated and non-halogenated flame retardants (FRs), this article progresses to cover nitrogen-, phosphorus-, and hybrid-based systems. The synthesis methods, structure–property relationships, and fire suppression mechanisms are critically discussed. A particular focus is placed on bio-based and waterborne formulations that align with green chemistry principles, such as tannic acid (TA), phytic acid (PA), lignin, and deep eutectic solvents (DESs). Furthermore, the integration of nanomaterials and smart functionalities into fire-resistant coatings has demonstrated promising improvements in thermal stability, char formation, and smoke suppression. Applications in real-world contexts, ranging from wood and textiles to electronics and automotive interiors, highlight the commercial relevance of these developments. This review also addresses current challenges such as long-term durability, environmental impacts, and the standardization of performance testing. Ultimately, this article offers a roadmap for developing safer, sustainable, and multifunctional fire-resistant coatings for future materials engineering. Full article

Occupational exposure to commercial formic and acetic acids through dermal contact and inhalation during rubber sheet processing poses significant health risks to workers. Additionally, the use of these acids contributes to environmental pollution by contaminating water sources and soil. This study investigates the potential of three types of wood vinegar—derived from para-rubber wood, bamboo, and eucalyptus—obtained through biomass pyrolysis under anaerobic conditions, as sustainable alternatives to formic and acetic acids in the production of ribbed smoked sheets (RSSs). The organic constituents of each wood vinegar were characterized using gas chromatography and subsequently mixed with fresh natural latex to produce coagulated rubber sheets. The physical and chemical properties, equilibrium moisture content, and drying kinetics of the resulting sheets were then evaluated. The results indicated that wood vinegar derived from para-rubber wood contained a higher concentration of acetic acid compared to that obtained from bamboo and eucalyptus. As a result, rubber sheets coagulated with para-rubber wood and bamboo vinegars exhibited moisture sorption isotherms comparable to those of sheets coagulated with acetic acid, best described by the modified Henderson model. In contrast, sheets coagulated with eucalyptus-derived vinegar and formic acid followed the Oswin model. In terms of physical and chemical properties, extended drying times led to improved tensile strength in all samples. No statistically significant differences in tensile strength were observed between the experimental and reference samples. The concentration of acid was found to influence Mooney viscosity, the plasticity retention index (PRI), the thermogravimetric curve, and the overall coagulation process more significantly than the acid type. The drying kinetics of all five rubber sheet samples displayed similar trends, with the drying time decreasing in response to increases in drying temperature and airflow velocity. Full article

Chestnut flour, obtained through drying and milling of Castanea sativa fruits, has evolved from a subsistence food into a sought-after niche product, appreciated for its naturally gluten-free profile, high starch content, and richness in micronutrients. Over the past decade, its demand has steadily increased due to consumer perception of the health benefits associated with chestnut consumption. As the market for chestnut flour expanded from small-scale to large-scale production, alternative methods to the traditional process were developed. Its distinctive aroma and flavor are strongly influenced by processing methods, which are the focus of this study. Two drying approaches were compared: a traditional smoke-based method (drying house named metato) characterized by a wood-drying method and a controlled laboratory process using a forced-air dryer that maintained a constant temperature of 40 °C. The impact of these methods on the physico-chemical composition, volatile organic compounds (VOCs), and sensory properties of the flour was evaluated using chemical, instrumental, and sensory analyses. The traditional method enhanced the flour’s aromatic complexity and typicity through the application of smoke, which has been demonstrated to generate volatile organic compounds (VOCs), such as guaiacol, furfural, and o-creosol, that are associated with the smoked aroma. Nevertheless, if not properly managed, it can lead to undesirable sensory notes due to excessive smoke exposure. In contrast, the laboratory-controlled process ensured better preservation of bioactive compounds—such as polyphenols (351 mg GAE/100 g dm) and ascorbic acid (322 mg/kg dm)—while retaining the aroma notes associated with fresh chestnuts. Optimizing processing methods may support the valorization of chestnut flour as a high-quality ingredient in the modern gluten-free and functional food market. Full article

The Wan’an Bridge, the longest wooden lounge bridge in China with a history of more than 900 years, was devastated by a catastrophic fire in 2022. This tragic event underscores the susceptibility of historical wooden structures to fire damage. In this article, the bridge’s intricate structure and the development of the fire incident are introduced in detail. To gain a deeper insight into the patterns of fire propagation across the bridge and assess the reliability of fire simulations in predicting fire spread in historical wooden structures, we utilized the Fire Dynamics Simulator (FDS), with a sophisticated pyrolysis model and thermal response parameters specifically tailored to ancient fir wood. The modeling results reveal that the FDS simulation reflects the actual fire spread process well. Both the investigation and simulation findings indicate that once the flame reaches above the bridge deck, it enters a rapid three-dimensional propagation phase that is exceptionally challenging to control. Furthermore, the modeling results suggest that the application of intumescent fire-retardant coatings can significantly delay fire spread, reduce heat release rates, and suppress smoke production, thereby making them an effective fire prevention measure for historical wooden buildings. Full article

Currently, workers in the ribbed smoked sheet (RSS) rubber production industry face increasing health risks, primarily due to their direct involvement in converting fresh latex into raw rubber sheets. This process involves the manual addition of appropriately diluted commercial formic acid and acetic acid to induce coagulation, resulting in a tofu-like consistency, which is subsequently processed into rubber sheets. Previous studies have indicated that the use of commercial formic and acetic acids poses significant health hazards to workers and contributes to environmental pollution. Therefore, this study explores the feasibility of replacing commercial formic and acetic acids with wood vinegar derived from para-rubber wood, bamboo, and eucalyptus in the RSS production process. Wood vinegar samples from the three biomass sources were analyzed for their organic compound compositions using gas chromatography and subsequently used as coagulants in the preparation of raw rubber sheets. The drying kinetics and antifungal properties of the resulting sheets were then evaluated. The results revealed that wood vinegar derived from para-rubber wood contained the highest concentration of acetic acid (41.34%), followed by bamboo (38.19%) and eucalyptus (31.25%). Rubber sheets coagulated with wood vinegar from para-rubber wood and bamboo exhibited drying kinetics comparable to those obtained using acetic acid, with the two-term exponential model providing the best fit. Conversely, rubber sheets coagulated with eucalyptus-derived wood vinegar, which had a relatively high concentration of phenolic derivatives (22.08%), followed drying behavior consistent with the Midilli et al. model, similar to sheets treated with formic acid. In terms of antifungal properties, five fungal genera—Aspergillus, Penicillium, Fusarium, Trichoderma, and Paecilomyces—were identified on the rubber sheets. Fungal growth was most pronounced in the control samples (untreated with wood vinegar), whereas samples treated with wood vinegar exhibited significantly reduced fungal colonization. These findings indicate that wood vinegar is effective in inhibiting fungal growth on the surface of rubber sheets and may serve as a safer and more environmentally friendly alternative to commercial acid coagulants. Full article

This study evaluates the impact of PM2.5 exposure from wood combustion on reproductive health and fetal development using an experimental model in Sprague Dawley rats. The study was conducted in Temuco, Chile, where high levels of air pollution are primarily attributed to residential wood burning. A multigenerational exposure model was implemented using controlled exposure chambers with filtered (FA) and unfiltered (NFA) air. Second-generation (G2) female rats (n = 48) were exposed pregestationally (60 days) and gestationally (23 days) under four conditions: FA/FA, FA/NFA, NFA/FA, and NFA/NFA. PM2.5 concentration and composition were monitored using beta-ray attenuation and X-ray fluorescence spectrometry. Reproductive parameters, ovarian follicle counts, and hormonal levels were assessed via vaginal cytology, histological analysis, and chemiluminescence immunoassays. PM2.5 exposure disrupted estrous cyclicity (p = 0.0001), reduced antral and growing follicles (p = 0.0020; p = 0.0317), and increased post-implantation losses (p = 0.0149). Serum progesterone and estradiol levels were significantly altered (p < 0.05). Despite ovarian disruptions, fertility rates remained unchanged. These findings suggest that chronic exposure to wood smoke-derived PM2.5 adversely affects ovarian function and fetal growth without significantly impairing overall reproductive capacity. This study highlights the need for public health policies to mitigate wood smoke pollution. Full article

This study is based on a 10-day survey carried out at seven beaches in March 2023 in El Puerto de Santa María municipality (SW Spain). An amount of 5592 items were collected, with a combined weight of 26 kg. Fresh litter, which refers to litter transported to the shore by marine/coastal processes, accounted for 4634 items weighing 23 kg. The remaining 958 items, weighing 3 kg, were identified as litter deposited by beach visitors. The average total litter recorded during the sampling was 0.40 ± 0.07 items m⁻¹ with a density of 1.85 ± 0.69 g m⁻¹. Litter materials were relatively consistent regardless of whether they were stranded by marine processes or discharged by beachgoers. Plastic dominates fresh and deposited litter followed by metal and glass, with minimal contributions of chemicals, organic matter, clothing, rubber, wood, and paper. They were identified 115 items’ categories from the 184 listed in the EU Joint List: 107 for fresh and 75 for deposited litter. Food consumption-related items made up a significant portion of the total debris followed by personal hygiene and care-related and smoking-related litter. The obtained information is very useful to propose sound management actions that have to be especially devoted to raise beach users’ responsibility. Last, in order to have a year-round view of litter characteristics and behavior, further investigations should be carried out during winter, when the number of visitors is very low and waves’ energy is high, and summer, when opposite conditions are recorded. Full article

To avoid carcinogenic polycyclic aromatic hydrocarbons, liquid smoke flavoring (LSF) is widely used by the meat industry, yet wood smoking remains a deep-rooted practice among Portuguese traditional dry-fermented producers. In this study, the use of LSF was compared with traditional smoking. In addition, two different ways of using LSF were also tested: spraying and mixing (during seasoning). The profiles of amino acids (AA) and biogenic amines (BA) were studied at pre-scheduled moments of processing and storage. When compared to smoked products, LSF did not affect total AA content; however, when mixed during seasoning, it inhibited the accumulation of arginine and lysine (precursors of BA) in final products. The conventional smoking replacement, by mixing LSF during seasoning, turned out to be critical to lessen BA of bacterial origin accumulation as well, especially for putrescine, cadaverine and tyramine. The benefits of spraying LSF over smoking were higher for final products than for storage, as differences between them tended to fade with time (except for tyramine). These results also demonstrate that a simple change in traditional dry-fermented sausage processing, such as mixing LSF during product seasoning, significantly contributes to the safety of these products through the reduction in undesirable BA. Full article

This work aimed to analyze the PAH content in products smoked in traditional smokehouses with direct and indirect heat sources and in an industrial way as an element of PAH content monitoring in Polish market products. This research material comprised 12 smoked meats (W) and 38 sausages (K), medium or coarsely minced. The content of benzo(a)pyrene and the total content of four marker PAHs was determined by GC-MS. The analysis showed a significantly higher level of PAH contamination in products smoked using traditional methods. The results also indicate that the natural casing is not a barrier against PAH contamination during traditional smoking, and a higher degree of meat fragmentation, together with a small cross-section, increases the PAH content in this technological group. Concentrations of benzo(a)pyrene exceeding the permissible levels were found in the sausages smoked for more than 60 min. As part of the strategies for reducing the PAH content, among others, changing the furnace to an indirect one, shortening the time, lowering the smoking temperature, using artificial casings or removing casings before consumption, drying the product surface before the smoking process, using seasoned and bark-free wood, as well as additional smokehouse equipment, are recommended. Full article

Background: Aortic valve calcification results from degenerative processes associated with several pathologies. These processes are influenced by age, chronic inflammation, and high concentrations of phosphate ions in the plasma, which contribute to induce mineralization in the aortic valve and deterioration of cardiovascular health. Environmental factors, such as wood smoke that emits harmful and carcinogenic pollutants, carbon monoxide (CO), and nitrogen oxide (NO_x), as well as other reactive compounds may also be implicated. The purpose of this research was to study the impact of wood smoke on specific aortic valve characteristics, including lesion size and percentage of mineralization, in patients with aortic valve stenosis (AS). Methods: This observational study included 65 patients who underwent primary valve replacement surgery at the National Institute of Cardiology, 11 of whom were exposed to wood smoke. For each patient, approximately 0.5 cm of aortic valve tissue was collected along with a blood sample anticoagulated with sodium citrate. The valves were analyzed using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM–EDS). Since extracellular microvesicles (MVs) may induce epigenetic changes in target cells by transferring their cargo, we also analyzed their mineral content. Results: Individuals exposed to wood smoke exhibit more extensive lesion (835 µm²) characteristics compared to those with no exposure (407.5 µm²). Interestingly, FESEM images of MVs showed the presence of minerals on their surface, thus providing evidence on their possible role in the pathophysiology of mineralization. Conclusions: Our study uniquely demonstrates imaging-based evidence of structural damage and mineralization in aortic valve tissue, with chronic wood smoke exposure emerging as a significant causative factor. Full article

Wooden structures are prone to fire hazards, and studying their combustion properties is vital for their protection. Samples of fresh pine wood (FP) and pine subjected to artificially accelerated aging (treated at 240 circulation) were collected and prepared for analysis. The heat-release rate, smoke production, and yields of carbon monoxide (CO) and carbon dioxide (CO₂) from both types of pine were assessed using conical calorimetry to determine their combustion characteristics. A historic building in Xi’an was modeled using PyroSim to serve as a representative case. The experimentally obtained combustion characteristics of the two pine wood types were inputted into the model, and the Fire Dynamics Simulator (FDS) software was utilized to simulate the development of fire in both newly constructed and aging historic buildings. The results suggest that aging impairs the wood’s combustion properties and increases the susceptibility of pine to ignition. Consequently, this accelerates the spread of fire in wooden structures, leading to a rapid increase in temperature and swift smoke production during fires, thus amplifying the fire risk to historic wooden buildings. Full article

In this study, different combinations of mycelium biocomposites (MBs) were developed using primary substrates sourced from the local agricultural, wood processing, and paper industries. The physicomechanical properties, thermal conductivity, and fire behavior were evaluated. The highest bending strength was achieved in composites containing waste fibers and birch sanding dust, with a strength competitive with that of synthetic polymers like EPS and XPS, as well as some commercial building materials. The lowest thermal conductivity was observed in hemp-based MB, with a lambda coefficient of 40 m·W·m⁻¹·K⁻¹, making these composites competitive with non-mycelium insulation materials, including synthetic polymers such as EPS and XPS. Additionally, MB exhibited superior fire resistance compared to various synthetic foams and composite materials. They showed lower peak heat release rates (134–243 k·W·m⁻²) and total smoke release (7–281 m²·m⁻²) than synthetic polymers, and lower total heat release (6–62 k·W·m⁻²) compared to certain wood composites. Overall, the mechanical and thermal properties, along with the fire performance of MB, support their potential as a sustainable alternative to petroleum-based and traditional composite materials in the building industry. Full article