Burning Smoke Research Articles

Poganek rutowaty (Peganum harmala L.) w tradycjach ludów Azji Środkowej i jego popularność w dobie pandemii COVID-19 – perspektywa antropologii medycznej

Syrian rue (Peganum harmala L.) in Central Asian traditions and its popularity in the time of the COVID-19 pandemic: perspective of medical anthropology Syrian rue (Peganum harmala L.) has been traditionally used in Central Asia for medical purposes, e.g. for treating skin diseases, joint pain, sore throat and cough. It is also applied as an apotropaic means – fumigation with the smoke of burning dried twigs of Syrian rue is commonly practised to ward off evil spirits, “evil eye” and other malevolent forces. According to the other explanations, it has purifying effects and kills microbes. In this article I briefl y outline early descriptions of Peganum harmala in the medical texts of scholars and physicians representing Greek- Arabic-Persian medicine, and focus on the role of this plant in people’s everyday life in Central Asia, based on my field materials from Afghanistan, Kazakhstan and Kyrgyzstan, and literature. In addition, I present the career of Peganum harmala in Central Asian countries during the COVID-19 pandemic, when fumigation with its smoke has been widely practised to protect against the coronavirus. Syrian rue was also used – beside several other plants – by some heads of state, who promoted local traditional medicines at time when they were failing to tackle the pandemic crisis. Applying an anthropological perspective, I pay particular attention to the wider context of these developments and analyse socio-cultural, political and economic factors that have contributed to the increased popularity of Peganum harmala. I also point out possible benefits of testing traditional herbal medicines as potential treatments for COVID-19 and other viral infections and refer to Asian traditional medical systems, especially traditional Chinese medicine (TCM), whose contribution to overcoming the pandemic has been recognised by the WHO.

Remote sensing and model analysis of biomass burning smoke transported across the Atlantic during the 2020 Western US wildfire season

Biomass burning is the main source of air pollution in several regions worldwide nowadays. This predominance is expected to increase in the upcoming years as a result of the rising number of devastating wildfires due to climate change. Harmful pollutants contained in the smoke emitted by fires can alter downwind air quality both locally and remotely as a consequence of the recurrent transport of biomass burning plumes across thousands of kilometers. Here, we demonstrate how observations of carbon monoxide and aerosol optical depth retrieved from polar orbiting and geostationary meteorological satellites can be used to study the long-range transport and evolution of smoke plumes. This is illustrated through the megafire events that occurred during summer 2020 in the Western United States and the transport of the emitted smoke across the Atlantic Ocean to Europe. Analyses from the Copernicus Atmosphere Monitoring Service, which combine satellite observations with an atmospheric model, are used for comparison across the region of study and along simulated air parcel trajectories. Lidar observation from spaceborne and ground-based instruments are used to verify consistency of passive observations. Results show the potential of joint satellite-model analysis to understand the emission, transport, and processing of smoke across the world.

Accuracy Assessment of Drone Real-Time Open Burning Imagery Detection for Early Wildfire Surveillance

Open burning is the main factor contributing to the occurrence of wildfires in Thailand, which every year result in forest fires and air pollution. Open burning has become the natural disaster that threatens wildlands and forest resources the most. Traditional firefighting systems, which are based on ground crew inspection, have several limits and dangerous risks. Aerial imagery technologies have become one of the most important tools to prevent wildfires, especially drone real-time monitoring for wildfire surveillance. This paper presents an accuracy assessment of drone real-time open burning imagery detection (Dr-TOBID) to detect smoke and burning as a framework for a deep learning-based object detection method using a combination of the YOLOv5 detector and a lightweight version of the long short-term memory (LSTM) classifier. The Dr-TOBID framework was designed using OpenCV, YOLOv5, TensorFlow, LebelImg, and Pycharm and wirelessly connected via live stream on open broadcaster software (OBS). The datasets were separated by 80% for training and 20% for testing. The resulting assessment considered the conditions of the drone’s altitudes, ranges, and red-green-black (RGB) mode in daytime and nighttime. The accuracy, precision, recall, and F1-Score are shown for the evaluation metrics. The quantitative results show that the accuracy of Dr-TOBID successfully detected open burning monitoring, smoke, and burning characteristics, where the average F1-score was 80.6% for smoke detection in the daytime, 82.5% for burning detection in the daytime, 77.9% for smoke detection at nighttime, and 81.9% for burning detection at nighttime.

Evolution of the corrosion layer of Q235 steel in simulated fire‐scene smoke

AbstractThe ability to accurately identify fire patterns is the fundamental requirement for fire investigations. The corrosion layers of steel in fire scenes exhibit three distinct characteristics. First, due to steel's nonflammable nature, steel patterns can be preserved better at the fire site than patterns formed on other combustible materials; second, both the high temperature and the smoke during the fire affect the high‐temperature oxidation process; and third, the corrosion layer of steels inevitably undergoes further evolution after the fire because of the subsequent room‐temperature corrosion. This study focuses on investigating Q235 steel because of its extensive use in construction and vehicles. The pattern evolution processes of high‐temperature oxidation at elevated temperatures in air, polyethylene (PE), and polyvinyl‐chloride (PVC) combustion smoke and the corresponding subsequent corrosion at room temperature were systematically investigated from the perspective of macroscopic and microscopic morphology. The results showed that the smoke atmosphere played an important role in the formation of the corrosion layer of Q235 steel. Compared with samples oxidized in air, samples oxidized in PE combustion smoke exhibited a uniform and dense oxide layer on the surface, which inhibited the corrosion at room temperature further. The PVC combustion smoke accelerated the high‐temperature oxidation of the sample, and its influence on the subsequent room‐temperature oxidation process was closely correlated with the temperature of the high‐temperature oxidation. The results of this study provide important references for understanding the formation of the corrosion layer of Q235 steel for fire investigations.

Experimental Study on Combustion and Fire Smoke Characteristics of Wallpapers using Smoke Density Chamber

During a fire, flames can quickly spread throughout the room because the wallpaper covers the entire surface. Smoke generated from fire is a significant obstacle to evacuation. Therefore, it is essential to study the smoke characteristics of the wallpaper to ensure evacuation safety. This study used the ISO 5659-2 combustion chamber method to measure the smoke density over time with and without flame conditions using a 25 kW/m<sup>2</sup> radiation heat flux. The extinction coefficient represents the visibility in the smoke, and VOF4 shows the initial combustion smoke density characteristics. These two factors were derived from experiment results. Paper, cork, and cotton wallpapers were used as representative wallpapers. The results show that the maximum smoke density of all wallpapers was higher in the non-flame condition than in the flame condition. Under the flame condition, the maximum smoke density was measured in the order of cork, cotton, and paper. In the non-flame condition, the order was cotton, cork, and paper with the maximum smoke density. The extinction coefficient of wallpapers, except paper, exceeded 1.0 m<sup>-1</sup> in the flame condition, indicating that the smoke density provides visibility of 1-2 m under fire.

Extended fuel properties of sustainable aviation fuel blends derived from linalool and isoprene

Seven different sustainable aviation fuel blends were prepared with hydrocarbons derived from terpenoid precursors. The first, designated as L-Jet, was formulated with various molecules produced from linalool (a terpene alcohol) including hydrogenated methylcyclopentadiene dimers, p-menthane, 2,6-dimethyloctane, and hydrogenated isobutylene trimers. L-Jet was also blended with a synthetic paraffinic kerosene derived from fatty acids and esters (HEFA-Jet) as well as Jet-A. The other four sustainable aviation fuel blends consisted of either Jet-A or HEFA-Jet mixed with cyclic hydrogenated isoprene dimers that can be readily produced from the bio-based hemiterpene, isoprene. To determine the suitability of these blends as surrogates for conventional jet fuel, a number of properties including density, low temperature viscosity, heat of combustion, flashpoint, corrosion, smoke point, conductivity, simulated distillation, existent gum, lubricity, thermal stability, and derived cetane number were measured. The 100 % SAF blends exhibited higher gravimetric heats of combustion and higher smoke points (less soot) compared to the blends with Jet-A. Several of the blends met American Society of Testing and Materials (ASTM) requirements, suggesting that they are promising candidates for certification as next generation aviation fuels.

Cannabis and Nicotine Dual Use among Sexual Minority Individuals: Relations to Cannabis Use and Negative Affect

Background: Sexual minority individuals report significantly more cannabis use and use-related problems than their heterosexual peers, and emerging data indicate sexual minority individuals who use cannabis are at greater risk for dual use of nicotine products (combustible smoking, e-cigarette use) than heterosexual individuals. Although cannabis–nicotine dual use is related to worse cannabis outcomes and negative affect, little work has identified factors related to dual use among sexual minority individuals or tested if sexual orientation-based discrimination (microaggressions, overt discrimination) is related to dual use. Objectives: The current study tested if cannabis–nicotine dual use is related to more frequent cannabis use, more cannabis-related problems, negative affect, and discrimination among sexual minority undergraduate students who endorsed current (past three-month) cannabis use (N = 328), 43.6% of whom endorsed dual nicotine use. Cannabis–nicotine dual use was related to more frequent cannabis use, more cannabis-related problems, more anxiety (but not depression), and more sexual orientation-based microaggressions and microaggressions-related negative affect (but not overt discrimination or non-sexual orientation-based daily stressors). Conclusions/Importance: Overall, this is the first known study to identify that sexual orientation-based discrimination is related to cannabis–nicotine dual use and that dual use is related to more frequent cannabis use, use-related problems, and negative affect (especially anxiety) among this underrepresented group.

Black carbon concentrations and modeled smoke deposition fluxes to the bare-ice dark zone of the Greenland Ice Sheet

Abstract. Ice–albedo feedbacks in the ablation region of the Greenland Ice Sheet (GrIS) are difficult to constrain and model due, in part, to our limited understanding of the seasonal evolution of the bare-ice region. To help fill observational gaps, 13 surface samples were collected on the GrIS across the 2014 summer melt season from patches of snow and ice that were visibly light, medium, and dark colored. These samples were analyzed for their refractory black carbon (rBC) concentrations and size distributions with a single-particle soot photometer coupled to a characterized nebulizer. We present a size distribution of rBC in fresh snow on the GrIS and from the weathering crust in the bare-ice dark zone of the GrIS. The size distributions from the weathering crust samples appear unimodal and were overall smaller than the fresh snow sample, with a peak around 0.3 µm. The fresh snow sample contained very large rBC particles that had a pronounced bimodality in the peak size distributions, with peaks around 0.2 and 2 µm. rBC concentrations ranged from a minimum of 3 µg-rBC/L-H2O in light-colored patches at the beginning and end of the melt season to a maximum of 32 µg-rBC/L-H2O in a dark patch in early August. On average, the rBC concentrations were higher (20 ± 10 µg-rBC/L-H2O) in patches that were visibly dark, compared to medium patches (7 ± 2 µg-rBC/L-H2O) and light patches (4 ± 1 µg-rBC/L-H2O), suggesting that BC aggregation contributed to snow aging on the GrIS, and vice versa. Additionally, concentrations peaked in light and dark patches in early August, which is likely due to smoke transport from wildfires in northern Canada and Alaska, as supported by the Navy Aerosol Analysis and Prediction System (NAAPS) reanalysis model. According to the model output, 26 mg m−3 of biomass-burning-derived smoke was deposited between 1 April and 30 August, of which 85 % came from wet deposition, and 67 % was deposited during our sample collection time frame. The increase in the rBC concentration and size distributions immediately after the modeled smoke deposition fluxes suggest that biomass burning smoke is a source of BC to the dark zone of the GrIS. Thus, the role of BC in the seasonal evolution of the ice–albedo feedbacks should continue to be investigated in the weathering crust of the bare-ice zone of the GrIS.

Changes in Physicochemical Properties of Organic Aerosol During Photochemical Aging of Cooking and Burning Emissions

AbstractPhotochemical aging is a key atmospheric processing, yet the changes in physicochemical properties of organic aerosol (OA) during photochemical aging of primary emissions from cooking and burning are less understood. Here we conducted 12 burning (straw, wood, and coal) and cooking experiments to characterize the evolution of size distributions, volatility, and glass transition temperature (Tg) from fresh smoke to aged OA with an equivalent photochemical age of ∼1.5 days using an oxidation flow reactor‐thermodenuder‐aerosol mass spectrometer system. The mass spectra of OA showed significant changes during photochemical aging, for example, the rapid degradation of m/z 60 for straw and wood burning OA, and the large increase in f44 (fraction of m/z 44 in OA) for all OA. The contributions of non‐volatile compounds to the total OA in aged burning OA (1.6%–5.3%) decreased considerably compared with those in fresh burning smoke (2.3%–17.1%), suggesting that photochemical aging of primary emissions for ∼1.5 days produced more volatile secondary OA (SOA). Consistently, the pronounced formation of SOA below 150 nm was observed, and it showed more volatile properties than aged large particles. The Tg of OA under dry conditions (Tg,org) was estimated based on volatility distributions, and the results showed increased Tg,org during photochemical aging of biomass burning and coal combustion emissions, while decreased Tg,org for aged cooking OA. Overall, our results illustrate the different changes in size distributions, volatility, and Tg,org through photochemical aging of different primary emissions, which in turn affect their impacts on radiative forcing and human health.

Photoaging of phenolic secondary organic aerosol in the aqueous phase: evolution of chemical and optical properties and effects of oxidants

Abstract. While gas-phase reactions are well established to have significant impacts on the mass concentration, chemical composition, and optical properties of secondary organic aerosol (SOA), the aqueous-phase aging of SOA remains poorly understood. In this study, we performed a series of long-duration photochemical aging experiments to investigate the evolution of the composition and light absorption of the aqueous SOA (aqSOA) from guaiacyl acetone (GA), a semivolatile phenolic carbonyl that is common in biomass burning smoke. The aqSOA was produced from reactions of GA with hydroxyl radical (•OH-aqSOA) or a triplet excited state of organic carbon (3C∗-aqSOA) and was then photoaged in water under conditions that simulate sunlight exposure in northern California for up to 48 h. The effects of increasing aqueous-phase •OH or 3C∗ concentration on the photoaging of the aqSOA were also studied. High-resolution aerosol mass spectrometry (HR-AMS) and UV–Vis spectroscopy were utilized to characterize the composition and the light absorptivity of the aqSOA and to track their changes during aging. Compared to •OH-aqSOA, the 3C∗-aqSOA is produced more rapidly and shows less oxidation, a greater abundance of oligomers, and higher light absorption. Prolonged photoaging promotes fragmentation and the formation of more volatile and less light-absorbing products. More than half of the initial aqSOA mass is lost, and substantial photobleaching occurs after 10.5 h of prolonged aging under simulated sunlight illumination for 3C∗-aqSOA and 48 h for •OH-aqSOA. By performing positive matrix factorization (PMF) analysis of the combined HR-AMS and UV–Vis spectral data, we resolved three generations of aqSOA with distinctly different chemical and optical properties. The first-generation aqSOA shows significant oligomer formation and enhanced light absorption at 340–400 nm. The second-generation aqSOA is enriched in functionalized GA species and has the highest mass absorption coefficients in 300–500 nm, while the third-generation aqSOA contains more fragmented products and is the least light absorbing. These results suggest that intermediately aged phenolic aqSOA is more light absorbing than other generations, and that the light absorptivity of phenolic aqSOA results from a competition between brown carbon (BrC) formation and photobleaching, which is dependent on aging time. Although photoaging generally increases the oxidation of aqSOA, a slightly decreased O/C of the •OH-aqSOA is observed after 48 h of prolonged photoaging with additional •OH exposure. This is likely due to greater fragmentation and evaporation of highly oxidized compounds. Increased oxidant concentration accelerates the transformation of aqSOA and promotes the decay of BrC chromophores, leading to faster mass reduction and photobleaching. In addition, compared with •OH, photoaging by 3C∗ produces more low-volatility functionalized products, which counterbalances part of the aqSOA mass loss due to fragmentation and evaporation.

Toxicity of fresh and aged anthropogenic smoke particles emitted from different burning conditions

There is substantial evidence that photochemical reactions in the atmosphere cause physico-chemical transformation of combustion smoke, but how this processing modifies potential health effects in exposed populations is not well understood. Here we utilized a new approach to simulate photochemical aging of anthropogenic smoke emissions (a mixture of plastic, plywood, and cardboard smoke) from two different burning conditions (smoldering vs. flaming) and investigated their adverse outcomes associated with mutagenic activity and the relative potencies of different polycyclic aromatic hydrocarbons (PAHs). Aging resulted in increased oxygenated volatile organic compound (VOC) emissions but largely degraded particle-bound PAH components in the smoke. Chemical transformation during aging was more dramatic for flaming versus smoldering smoke. Due to the PAH degradation, mutagenicity of the aged smoke from flaming combustion was much lower (up to 4 times) than that of the fresh smoke on per-particle mass basis. However, on the basis of particle emitted per fuel mass burned, the aged and fresh smoke particles exhibited similar mutagenic activities, which were up to 3 times higher for smoldering versus flaming smoke emissions. Similarly, the PAH toxicity equivalent (PAH-TEQ) of the aged smoldering smoke was 3 times higher than that of the aged flaming smoke particles, suggesting that some PAHs (e.g., indeno[c,d]pyrene and benzo[b]fluoranthene) in the smoldering smoke were more photochemically stable during aging. These findings increase understanding of the evolution of smoke emitted at different burning conditions and the role of photochemical transformations on mutagenicity and PAH-induced toxicity.

DEVELOPMENT OF HERBAL MOSQUITO-REPELLENT FORMULATIONS AND THEIR COMPARATIVE EVALUATION

Objective: The present research work aimed to develop herbal mosquito repellents as gels, incense sticks, and liquids for plug-in devices and also to assess their performance characteristics. Methods: Herbal materials possessing mosquito-repellent activity were selected from the literature review based on percentage repellency and protection period. In this study, lavender, rosemary, lemongrass, and cedarwood oils were selected as actives. Span 20 and tween 80 were used to emulsify the volatile materials and then incorporated into Carbopol 934 base to form F1 and F2 gels which were evaluated for homogeneity, pH, spread ability, viscosity, and extrudability. Incense sticks were developed using charcoal and jigat as base materials. The prepared incense sticks F3 and F4 were evaluated for burning time, ash weight, and smoke. Solutions F5 and F6 were prepared using surfactants and cosolvents and were evaluated for phase separation. All formulations were screened for their mosquito repellency by screen cage method and their performance was compared to that of the marketed herbal repellents. Results: Reared mosquitoes were identified as Culex species by microscopical observations of the antenna and maxillary palps. Mosquito repellency in 4 h is 93%, 87%, 89%, 79%, 89%, and 85% for F1, F2, F3, F4, F5 and F6, respectively. Among all, gel formulation F1 expressed the highest mosquito-repellent activity with 93% and is a better candidate. Conclusions: Gel, incense sticks, and liquids prepared for use in plug-in devices exhibited reasonably good percentage repellency comparable to that of the standard. All the developed formulations are suitable for indoor protection from mosquito bites. However, safety, stability, and field studies need to be carried out to demonstrate suitability for regular use.

Coconut Shell Carbonization Process Using Smokeless Kiln

Proper processing of coconut shell charcoal can be highly economically and environmentally valuable. The two most common uses of coconut shell charcoal are activated carbon and briquettes, obtained through carbonization. However, traditional carbonization methods involving kilns can produce excessive smoke, polluting the environment and disrupting human activities. A carbonization kiln that produces less smoke is required to address this issue. In this study, a kiln made from a steel drum with a sealer belt was fabricated to trap burning smoke inside the kiln. The results showed that adding this belt effectively reduced the smoke produced, making it more eco-friendly. Regarding charcoal production efficiency, different weigh coconut shells were burnt to produce charcoal. The result showed that burning 25 kg of coconut shell was optimal, producing a 48% charcoal content.

The impact of depression on opioid withdrawal symptoms among smokers with opioid use disorder receiving medication-assisted opioid detoxification.

Individuals with opioid use disorder (OUD) endorse high rates of combustible smoking (Zale et al., 2015) which is associated with poorer outcomes (e.g., opioid craving and lower detoxification completion rates) among individuals receiving medications for opioid use disorder (MOUD; Mannelli et al., 2013) and lower smoking cessation rates (Okoli et al., 2010). The complex pharmacological relationship between opioids and nicotine may help explain these findings (Kohut, 2017); however, little is known about psychosocial variables that influence MOUD processes among combustible smokers with OUD. The present study sought to expand upon prior work (Mannelli et al., 2013) by examining the impact of psychological factors and smoking-related variables on opioid withdrawal symptoms among smokers with OUD receiving Suboxone at an inpatient substance use treatment facility. Current smokers with OUD (N = 64) completed a battery of psychological measures examining depression, anxiety, and smoking constructs. The present study tested the influence of daily smoking rate, nicotine dependence, smoking urges, anxiety, and depression on opioid withdrawal symptoms through a hierarchical multiple regression. Findings revealed that smoking urges (p = .003) predicted severity of opioid withdrawal symptoms while controlling for race, daily smoking rate, and nicotine dependence. Depression (p = .000), however, explained variance in severity of opioid withdrawal symptoms above and beyond all smoking-related variables and anxiety. Results highlight the importance of considering psychological factors, specifically depression, which impact treatment processes among smokers with OUD to help inform the development of effective treatment interventions for both OUD and smoking cessation among individuals with OUD. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

The Substitution of Fifty Percent of Combustible Tobacco Smoke Exposure With Either Electronic Cigarettes or Heated tobacco Products Did Not Attenuate Acute Lung Injury in an Animal Model.

To reduce the harmful health effects of combustible cigarette smoke (CS), some (CS) users attempt to substitute CS with electronic cigarettes (ECIG) and/or heated tobacco products (HTP). In this animal study, we evaluated the acute effects of substituting CS consumption with ECIG or HTP thus mimicking the dual users' approach, on the lungs of a mouse model. C57BL/6 mice were divided into Control, ECIG, HTP, CS, ECIG + CS, HTP + CS, and HTP + ECIG groups. Animals were exposed for 3 hours in AM and PM sessions to either air, CS, ECIG, or HTP for seven days. Lung injury was assessed by: wet to dry (W/D) ratio, albumin concentration in bronchoalveolar lavage fluid, expression of IL-1β, IL-6, and TNF-α, histopathology examination, reactive oxygen species (ROS) production, and assessment of cellular apoptosis. W/D ratio was significantly increased in mice exposed to CS only. Albumin leak and expression of IL-1β, IL-6, and TNF-a were elevated in CS, ECIG + CS, and HTP + CS. Histological examination revealed significant inflammatory cells infiltration, as well as collagen deposit in CS, ECIG + CS, HTP + CS. ROS production was significantly increased in CS, ECIG + CS, HTP + CS. Finally, cell death was also significantly increased in CS, ECIG + CS, and HTP + CS. In this animal model, substituting 50% of daily CS exposure by either ECIG or HTP exposure did not result in significant attenuation of acute lung injury.

Knowledge, Perceptions and Use of Electronic Cigarettes Among Health Professionals

In the developing era we are facing increasing prevalence of tobacco use and rapid increase of e-cigarette. Health professional are no longer found to abstain from e-cigarettes. The growing interest of vaping in our society leads to us a debate that e-cigarette are the tools to refrain from smoking or these are provoking people towards more smoking. Objectives: to evaluate the knowledge and concepts of e-cigarettes. And how the health professional perceive the use of vaping over smoking tobacco? What are the attitudes of vaping in health care professional? Methods: A descriptive cross-sectional study based on questionnaire filling survey, filled by 350 health professionals working in Jinnah hospital Lahore. The questionnaire compromises on four parts; demographic data, knowledge and attitudes toward vaping behavior, interest and trend of e-cigarettes, and perception of harms and health related risks. Results: data collected from 350 individuals. Average age of health professionals included in study was 30.6(2.60). A large percentage was found for former smokers 22% and current smokers 39%. Vape users also found in increasing percentages.so far the mass media roles were evaluated in smoking cessations. A cumulative percentage of 42%, electronic cigarettes were supported by the health professionals. Despite of good knowledge most of the professional had opinion in support of e-cigarettes upto 64% and the results were significantly proven by p-value 0.03. the knowledge and attitudes that e-cigarettes is less harmful than combustible tobacco smoking with and cumulative percent of 76% . Conclusion: health care professionals working in Jinnah hospital Lahore have favorable attitudes towards vaping or e-cigarettes perceived thought of vaping is less harmful than tobacco smoking is also highlighted. The need of the hour is to highlight the health related problems by e-cigarettes in our society to control the behaviors of population towards e-cigarettes.

Effect of a bio-based copolymer containing lysine, dopamine and triazine on flame retardancy and mechanical properties of thermoplastic polyurethane/ammonium polyphosphate

A bio-based copolymer (TDDL) containing lysine, dopamine, triazine was synthesized using cyanuric chloride, dopamine and lysine, respectively. The TDDL was used as a charring agent and ammonium polyphosphate (APP) was used as an acid source to improve the flame retardancy of thermoplastic polyurethane (TPU). The flame retardancy and thermal degradation behaviors of TPU blends were investigated using UL-94 vertical burning, limiting oxygen index (LOI), cone calorimetry tests and thermal gravimetric analysis (TGA). TPU blend containing 8 wt% APP displays a UL-94 V0 rating and a LOI value 30.0 vol%. While TPU blend containing 6 wt% APP/TDDL displays a UL-94 V0 and a LOI 29.6 vol% suggesting good synergistic effect between TDDL and APP. In addition, TDDL reduces the heat release rate of TPU/APP blend, and promotes the formation of a perfect char layer during the combustion process, and suppresses the release of combustible gas and smoke. Moreover, TPU blends have better modulus and elongation at break than those of TPU.

Toughening behavior and synergistic flame retardant effect of a ternary block copolymer with amorphous morphology and thermal softening property in polypropylene

A novel intumescent flame retardant with ternary block copolymer style not only more effectively enhanced flame retardant efficiency but also dramatically increased mechanical properties of polypropylene (PP) composites compared with traditional compounds. The ternary block copolymers were synthesized by the dehydration reaction of polydiphenylsiloxane, piperazine pyrophosphate oligomer and melamine phosphate. Among them, the ternary block copolymer T4-0.8PSi with particular unit ratio presented best comprehensive effect in PP composites. The LOI value of PP composite T4-0.8PSi/PP with 20 wt% T4-0.8PSi reached 30.2 %, and UL94 level of 1.6 mm spline passed V-0 rating. Compared with binary block copolymer B1 and the mixtures B1/0.8PSi and Mix/0.8PSi with similar contents as T4-0.8PSi, T4-0.8PSi obviously reduced the peak value of heat release rate, total heat release, effective heat of combustion and total smoke release. Particularly, it dramatically increased the residue yield and promoted the formation of denser and compact char layer. The ternary block copolymer T4-0.8PSi with appropriate group ratio generated synergistic charring effect in PP. At the same time, the mechanical properties of T4-0.8PSi/PP were dramatically enhanced and the impact strength was increased by 14.5 % compared with B1. Compared with the two mixtures just mentioned, the impact strength of T4-0.8PSi/PP increased by 48.8 % and 103.3 %, and the elongation at break increased by 601 % and 2056 %, respectively. The silicon-containing unit in ternary block copolymer nearly eliminated crystallinity to form amorphous morphology, which made flame retardants deform to droplet-like particles during processing, thus resulting in the more contact area and stronger interaction between the ternary block copolymer and polymer matrix. The research provided a new way for developing polyolefin materials with both high flame retardancy and excellent mechanical properties.

Characterization of organic aerosols at the Natura 2000 remote environment of Sanabria Lake (Spain): Evaluating the influence of African dust and regional biomass burning smoke

This work presents a thorough analysis of PM10 speciated organic composition at Sanabria Lake Natural Park, a rural remote area in NW-Spain, including diacids, hydroxy and poliacids, fatty acids, alkenoic acids, sugars, sugar alcohols, n-alkanes, PAHs, quinones, hopanes, tracers of biomass burning, and biogenic secondary organic aerosol (BSOA) from isoprene and α-pinene.PM10 ambient concentrations at Sanabria (mean value of 12.2 μg m−3) were within the typical range registered in regional-background air quality monitoring stations in Spain. However, the occurrence of African dust outbreaks and biomass burning events produced significant increases in the PM10 levels at this monitoring site (daily mean levels of 29.2 μg m−3 and 13.7 μg m−3, respectively).Major organic compounds were levoglucosan, sacharides and 2-methyltetrols, markers for biomass burning, soil dust and BSOA respectively.SOA contributed more than 53% of the total measured organics in summer Samples with high levels of SOA include most of the African dust events, suggesting that African dust might promote the formation of oxygenated species such as SOA derivatives in this area. This contribution decreased to a 14% in winter. Biomass burning tracers represented 37% of the analysed organic pollutants in winter, indicating that this is the main source of organic compounds in the colder seasons, mainly due to the influence of regional biomass burning events and the use of biomass as fuel in domestic heating. Hence, the fact that African dust outbreaks and biomass burning events are likely to become increasingly frequent in the context of climate change makes this type of analysis particularly relevant for assessing their impact on natural protected areas.

The online in situ detection of plastic and its combustion smoke via laser-induced breakdown spectroscopy

With the development of modern industry, it can be said that from industrial production to the basic necessities of life, plastic products can be seen everywhere. What follows is the disposal of plastic waste. How to deal with plastic waste correctly is closely related to people’s health and the earth’s environment. In this paper, laser-induced breakdown spectroscopy is applied for the online in situ detection of plastic and its combustion smoke. According to the spectrum obtained, the main components of plastics are Ca, Mg, Na, K, C, H and O. In the spectrum of smoke, the characteristic peaks of the elements C, H, O and N are observed. In addition, the online detection of heavy metal pollution is simulated. Finally, principal component analysis and error back propagation artificial neural networks were applied for the identification of different plastics and their combustion smoke, and the identification accuracy reaches 92.73% and 77.42% respectively. All the results indicate that laser-induced breakdown spectroscopy technology has great potential in the identification of similar objects and the monitoring of air pollutants.