Smoke Concentration Research Articles

Fatty acid profile and changes in quality of smoked barracuda fish (Sphyraena jello) with different concentrations of liquid smoke

Barracuda fish (Sphyraena jello) is an Indonesian marine capture fishery with high economic value and is in high demand among consumers because it has a delicious taste and complete nutritional profile. One of the nutrients contained in barracuda fish is fatty acids. Fatty acids are easily oxidized which causes a rancid odour in fish. The method of processing with smoking using liquid smoke can prevent oxidation in fish caused by the phenol content in liquid smoke which acts as an antioxidant. This study aimed to examine the effect of different concentrations of liquid smoke on the fatty acids of smoked barracuda fish. The experimental design used was RAL (completely randomized design), and analysis of variance (ANOVA) was used to analyze the data, and then the honestly significant difference test was performed. The treatments included the addition of liquid smoke with a concentration of 0% as control, 4%, 6% and 8% with three repetitions. The parameters tested were fatty acid profile, cholesterol content, moisture content, lipid content, phenol content, and organoleptic test. The results showed that applying liquid smoke can retain fat and fatty acids in smoked barracuda fish. The highest fatty acids in smoked barracuda fish were palmitic acid with a value of 1.084-1.618% (%w/w) for saturated fatty acids, oleic acid with a value of 0.469-0.764% (%w/w) for monounsaturated fatty acids, and EPA with values 0.104-0.143 (%w/w) for polyunsaturated fatty acids. The addition of liquid smoke with a concentration of 8% has the highest fatty acid content, producing a total value of 4.759%. The variation in liquid smoke concentration in smoked barracuda had a significant effect (P<0.05) on cholesterol levels, moisture content, protein, phenol, and organoleptic values of smoked fish.

Comprehensive evaluation of spray arrangement strategies for spray-local exhaust ventilation

A well-designed spray system, which is located near the source of high-temperature smoke, can improve the capture efficiency of traditional local exhaust ventilation (LEV). However, there is currently no comprehensive evaluation index that clearly reflects the performance of spray-local exhaust ventilation (SLEV), making it challenging to optimize the spray arrangement. The two-phase flow fields in the SLEV and LEV were compared to evaluate the impact of spray on smoke control. The effects of spray arrangement parameters, such as spray position, spacing, initial droplet size, and angle, on the performance of the SLEV system were further evaluated using current evaluation indicators. Based on this, we developed a comprehensive evaluation model for SLEV using the AHP-entropy combination weighting method. The results revealed that the decrease in smoke control with an increase in rolling speed is primarily caused by a reduction in spray control in the central region of the smoke. When the spray flow rate is 0.0028 kg/s and the velocity is 30 m/s, the primary factor that improves ventilation performance is the downward drag force exerted by the spray on smoke, rather than the cooling effect. The comprehensive model was developed using weights of 0.45, 0.34, and 0.21 for the three evaluation indicators: capture efficiency, high-quality concentration field ratio, and spatial droplet size. The model showed good reliability based on the results of the smoke concentration analysis. The results of this study are expected to guide the design, implementation, and evaluation of SLEV systems.

Impact of Biomass Burning Organic Aerosol Volatility on Smoke Concentrations Downwind of Fires.

Biomass burning particulate matter (BBPM) affects regional air quality and global climate, with impacts expected to continue to grow over the coming years. We show that studies of North American fires have a systematic altitude dependence in measured BBPM normalized excess mixing ratio (NEMR; ΔPM/ΔCO), with airborne and high-altitude studies showing a factor of 2 higher NEMR than ground-based measurements. We report direct airborne measurements of BBPM volatility that partially explain the difference in the BBPM NEMR observed across platforms. We find that when heated to 40-45 °C in an airborne thermal denuder, 19% of lofted smoke PM1 evaporates. Thermal denuder measurements are consistent with evaporation observed when a single smoke plume was sampled across a range of temperatures as the plume descended from 4 to 2 km altitude. We also demonstrate that chemical aging of smoke and differences in PM emission factors can not fully explain the platform-dependent differences. When the measured PM volatility is applied to output from the High Resolution Rapid Refresh Smoke regional model, we predict a lower PM NEMR at the surface compared to the lofted smoke measured by aircraft. These results emphasize the significant role that gas-particle partitioning plays in determining the air quality impacts of wildfire smoke.

A Numerical Study on the Smoke Dispersion and Temperature Distribution of a Ship Engine Room Fire Based on OpenFOAM

To further study the smoke dispersion and the temperature distribution in ship engine room fires, the fire dynamics solver buoyantReactingFOAM in the software OpenFOAM-10 is used to conduct a numerical simulation study on a pool fire caused by fuel oil leakage in a ship engine room. The applicability of this solver in simulating ship-engine-room-scale fires is validated by comparing it with experimental data. The impact of the mechanical ventilation, fire area, and fire position on the smoke dispersion and the temperature distribution in the ship engine room during the fire are considered in the simulation study, with a focus on the control room and the escape exit. The simulation results of buoyantReactingFOAM agree well with the experimental data. The simulated results of the case study show that for both in the control room and near the escape exit, among the factors of fire position, fire area, and the ventilation situation, the fire position affects the temperature distribution and the smoke dispersion most heavily, followed by the fire area and then the ventilation situation, which has the least influence on them. But, compared to the control room, the influence degree of the ventilation air velocity in the escape exit is larger than that in the control room. With an increase in the fire area, the spread rate of high temperature and high smoke concentration increases. With an increase in the ventilation air velocity, the aggregation degree of smoke and temperature decreases, but its decreasing range is very small when the ventilation air velocity is larger than 2 m/s.

Design of IoT Home System for the Elderly based on Different Scenarios

China has entered an aging society. Based on investigating the living status of the elderly and smart home products at home and abroad, this paper puts forward a smart home system design based on Internet of Things according to the life needs of the elderly. The system has the functions of daily data collection, data transmission and prompt alarm in real time, which can meet the needs of remote real-time monitoring. It can transmit the processed information to users in time and receive indoor temperature, smoke concentration and other home environment information at any time. Once a dangerous situation occurs, the smart home system will alert the user so that the user can take measures in time.

Intelligent Aircraft Hangar Fire Detection and Location System Based on Wireless Sensor Network

Aircraft hangar fire detection systems are essential for protecting both the facility's assets and the contents of an aircraft. In terms of predicting a fire outbreak at an aircraft hangar, the Intelligent Aircraft Hangar Fire detection is considered as a high-performance system that is designed based on the principle of a wireless sensor network (WSN), which operates by employing three sensor nodes at different locations inside the aircraft hangar to transmit gas concentrations in the air to a base station (BS) and send the resulting data from the sensor nodes to a server for analysis and visualization of the risk level. The server uses Machine Learning (ML) techniques to analyze the acquired data along with the sample gas data and displays the report in real time. When the smoke (gas) concentration is high, the server predicts a fire outbreak by displaying a high concentration zone on the Graphic User Interface (GUI). By this, the server automatically issues a warning and identifies the potential fire location. The technology is built to protect aircraft assets, hangar buildings, and human (personnel) life. A crucial part in the early detection of fire is played by the intelligent system

Study on Smoke Ventilation Performance According to the Opening Rate in a Corridor-Type Apartment

In case of household fire in in a corridor-type apartment, when the apartment door is opened smoke generated from the fire flows along the corridor, which is an evacuation passage, thereby considerably affecting evacuation safety. It is essential to prepare smoke control measures for the evacuation safety of occupants. In this study, a model corridor was constructed to examine the smoke ventilation performance according to the opening ratio of windows installed in an apartment corridor, and a small-scale empirical fire experiment was conducted to determine the changes in smoke concentration, thermal flow temperature, and smoke layer thickness. Additionally, the smoke ventilation performance was examined in the presence or absence of a sprinkler system under the same conditions. Comprehensively considering the results obtained in the experiment, it is desirable to secure a 100% opening rate of the corridor on the 15th floor and below without sprinklers in corridor-type apartments, exempt from smoke control equipment, and in accordance with related standards.

Microbial Analysis of Chicken “Urutan” Traditional Food With Different Smoke Processes

The chicken sequence is a processed meat product that is processed by making a complete Balinese meat, fat, and seasoning mixture and then put into a sleeve. This study aimed to investigate the impact of varying concentrations of coconut shell liquid smoke on the sequence features of chickens. The method used in this study is the descriptive analysis of microbial growth observations. The results showed that the use of coconut shell liquid smoke with a concentration of 4% could maintain chicken “urutan” for up to 20 days of storage at low temperatures (5+1 oC) with total microbial characteristics of 2.08 x 107 CFU/g, Escherichia coli < 103 CFU/g and Yeast mold 0 CFU/g (meet the requirements SNI 01-3820-2015)

Continuous aerosol monitoring and comparison of aerosol exposure based on smoke dispersion distance and concentrations during oxygenation therapy

This study evaluated the aerosol exposure risks while using common noninvasive oxygenation devices. A simulated mannequin was designed to breathe at a minute ventilation of 20 L/min and used the following oxygen-therapy devices: nasal cannula oxygenation (NCO) at 4 and 15 L/min, nonrebreathing mask (NRM) at 15 L/min, simple mask at 6 L/min, combination of NCO at 15 L/min and NRM at 15 L/min, high-flow nasal cannula (HFNC) at 50 L/min, and flush rate NRM. Two-dimension of the dispersion distance and the aerosol concentrations were measured at head, trunk, and foot around the mannequin for over 10 min. HFNC and flush-rate NRM yielded the longest dispersion distance and highest aerosol concentrations over the three sites of the mannequin than the other oxygenation devices and should use with caution. For flow rates of < 15 L/min, oxygenation devices with mask-like effects, such as NRM or NCO with NRM, decreased aerosol dispersion more effectively than NCO alone or a simple mask. In the upright position, the foot area exhibited the highest aerosol concentration regardless of the oxygenation device than the head–trunk areas of the mannequin. Healthcare workers should be alert even at the foot side of the patient while administering oxygenation therapy.

Levels of Urinary Mercapturic Acids of Acrolein, Methacrolein, Crotonaldehyde, and Methyl Vinyl Ketone in Relationship to Chronic Obstructive Pulmonary Disease in Cigarette Smokers of the Subpopulations and Intermediate Outcome Measures in COPD Study (SPIROMICS).

Cigarette smoking is an established cause of chronic obstructive pulmonary disease (COPD). Numerous studies implicate acrolein, which occurs in relatively high concentrations in cigarette smoke and reacts readily with proteins, as one causative factor for COPD in smokers. Far less is known about the possible roles in COPD of the related α,β-unsaturated carbonyl compounds of cigarette smoke crotonaldehyde, methacrolein, and methyl vinyl ketone. In the study reported here, we analyzed mercapturic acids of these α,β-unsaturated compounds in the urine of 413 confirmed cigarette smokers in the Subpopulations and Intermediate Outcome Measures in COPD Study (SPIROMICS)─202 with COPD and 211 without COPD. The mercapturic acids analyzed were 3-hydroxypropyl mercapturic acid (3-HPMA) from acrolein, 3-hydroxy-1-methylpropyl mercapturic acid (HMPMA-1) from crotonaldehyde, 3-hydroxy-2-methylpropyl mercapturic acid (HMPMA-2) from methacrolein, and 3-hydroxy-3-methylpropyl mercapturic acid (HMPMA-3) from methyl vinyl ketone. In models adjusting for age, sex, race, pack years of tobacco use, and BMI, all four mercapturic acids were increased in individuals with COPD but not significantly. Stratified by the GOLD status, there were increased levels of the metabolites associated with GOLD 3-4 compared to that with GOLD 0, with the methacrolein metabolite HMPMA-2 reaching statistical significance (adjusted odds ratio 1.23 [95% CI: 1.00-1.53]). These results highlight the possible role of methacrolein, which has previously received little attention in this regard, as a causative factor in COPD in cigarette smokers.

Emergency department visits respond nonlinearly to wildfire smoke

Air pollution negatively affects a range of health outcomes. Wildfire smoke is an increasingly important contributor to air pollution, yet wildfire smoke events are highly salient and could induce behavioral responses that alter health impacts. We combine geolocated data covering all emergency department (ED) visits to nonfederal hospitals in California from 2006 to 2017 with spatially resolved estimates of daily wildfire smoke PM[Formula: see text] concentrations and quantify how smoke events affect ED visits. Total ED visits respond nonlinearly to smoke concentrations. Relative to a day with no smoke, total visits increase by 1 to 1.5% in the week following low or moderate smoke days but decline by 6 to 9% following extreme smoke days. Reductions persist for at least a month. Declines at extreme levels are driven by diagnoses not thought to be acutely impacted by pollution, including accidental injuries and several nonurgent symptoms, and declines come disproportionately from less-insured populations. In contrast, health outcomes with the strongest physiological link to short-term air pollution increase dramatically in the week following an extreme smoke day: We estimate that ED visits for asthma, COPD, and cough all increase by 30 to 110%. Data from internet searches, vehicle traffic sensors, and park visits indicate behavioral changes on high smoke days consistent with declines in healthcare utilization. Because low and moderate smoke days vastly outweigh high smoke days, we estimate that smoke was responsible for an average of 3,010 (95% CI: 1,760-4,380) additional ED visits per year 2006 to 2017. Given the increasing intensity of wildfire smoke events, behavioral mediation is likely to play a growing role in determining total smoke impacts.

Air pollution and suicide in rural and urban America: Evidence from wildfire smoke

Air pollution poses well-established risks to physical health, but little is known about its effects on mental health. We study the relationship between wildfire smoke exposure and suicide risk in the United States in 2007 to 2019 using data on all deaths by suicide and satellite-based measures of wildfire smoke and ambient fine particulate matter (PM2.5) concentrations. We identify the causal effects of wildfire smoke pollution on suicide by relating year-over-year fluctuations in county-level monthly smoke exposure to fluctuations in suicide rates and compare the effects across local areas and demographic groups that differ considerably in their baseline suicide risk. In rural counties, an additional day of smoke increases monthly mean PM2.5 by 0.41 μg/m3 and suicide deaths by 0.11 per million residents, such that a 1-μg/m3 (13%) increase in monthly wildfire-derived fine particulate matter leads to 0.27 additional suicide deaths per million residents (a 2.0% increase). These effects are concentrated among demographic groups with both high baseline suicide risk and high exposure to outdoor air: men, working-age adults, non-Hispanic Whites, and adults with no college education. By contrast, we find no evidence that smoke pollution increases suicide risk among any urban demographic group. This study provides large-scale evidence that air pollution elevates the risk of suicide, disproportionately so among rural populations.

CFD Assessment of Car Park Ventilation System in Case of Fire Event

This scientific article presents the results of computational fluid dynamics (CFD) simulations conducted using OpenFOAM to evaluate the effectiveness of a jet fan ventilation system in managing the dispersion of smoke resulting from a car fire incident within an underground car park spanning a total area of 21,670 m2, situated in Tabriz, Iran. The primary objective of the study is to determine the velocity fields and evaluate visibility conditions within a 10 m radius to gauge the efficiency and effectiveness of the system. The study employs a smoke concentration production rate of 5.49 × 10−4 kg/m3s for simulations involving fire scenarios. A total of 17 fire scenarios are examined, each extending 30 m in all directions from the initial location. The research findings demonstrate that the placement of jet fan components plays a significant role in the system’s efficiency, with fans positioned near the ceiling leading to back-layering. To mitigate this issue, the recommended design solution involves the strategic installation of multiple jet fan arrays in specific zones with the addition of 10 extra jet fans, effectively curbing lateral smoke dispersion. Furthermore, the analysis of air flow rates shows that when jet fans direct an excessive airflow towards the exhaust shafts (which have a designated flow rate of 22.5 m3/s), recirculating flows occur, leading to the dispersion of smoke throughout the car park. Consequently, the utilization of low-velocity jet fans (11.2 m/s) proves to be more effective in clearing smoke compared to high-velocity jet fans (22.3 m/s). The study also emphasizes the importance of optimal positioning of supply and exhaust shafts to achieve effective smoke control, highlighting the need for placing them on opposite walls or minimizing airflow turns. Additionally, the research underscores the significance of fire resistance in jet fan units, as their failure during fire incidents can have severe consequences.

A Study on Numerical Model Uncertainty of Smoke Concentration in Fire Simulation

The prediction accuracy of smoke concentration related to visibility in fire hazard assessment using fire simulation contains a significant error compared to gas temperature and toxic gas concentration. However, the results are limited because the prediction uncertainty of smoke concentration was reviewed through specific fuels and experimental conditions. This study conducted experiments and simulations to evaluate the prediction uncertainty of smoke concentration in the numerical model using various fire conditions. Consequently, as various fuel and experimental conditions were applied, the predicted smoke concentration using fire simulation was confirmed to have a relative error from –45% to 520% based on the measurement data. Moreover, it was also confirm that the dependence on fuel types was significant.

Experimental analysis of airborne contaminant distribution in an operating room with different ventilation schemes

Experimental and numerical investigations were performed in a research operating room to compare laminar air flow and turbulent mixing ventilation systems in reducing the concentrations of airborne germs and surgical smoke in operating room air. In addition, measurements at scattered positions were conducted to find positions that are suited best for airborne monitoring in real-time during surgeries. In the experiments, particle counters were used to sample tracer aerosols originating from the wound area and the facial area of the thermal manikins representing surgical staff. The results showed that it is important to perform monitoring close to the areas with high hygiene requirements. Increasing the air change rate with turbulent mixing ventilation significantly reduced the number of airborne particles, however, not in the surgical microenvironment. Our findings show varying results considering the particle concentration using laminar air flow compared to turbulent mixing ventilation. With laminar air flow, higher contaminant levels are obtained in the areas with a high demand for contamination reduction. In contrast, laminar air flow was more effective in reducing the concentration of surgical smoke in the facial areas of the surgical staff. Regarding airborne germs, monitoring should be performed at the instrument tables and close to the wound area to evaluate the risk for surgical side infections. These results can support the development of guidelines and best practices for operating room ventilation design and maintenance to improve patient safety and reduce the risk of healthcare-associated infections.

The effectiveness of coconut coir liquid smoke as a natural insecticide on the mortality of Spodoptera exigua Hubner (Lepidoptera: Noctuidae)

This research was conducted at the Laboratory of Pests and Diseases, Faculty of Agriculture, University of Tadulako, Palu, from Juli 2022 to November 2022. This study used a Complete Randomized Design (CRD) which consisted of 5 treatments that were repeated 4 times to obtain 20 experimental units. The treatments were K1 = (control), K2 = liquid coconut coir smoke concentration of 2.5 ml/L, K3 = liquid coconut coir smoke concentration of 5 ml/L, K4 = liquid coconut coir smoke concentration of 7.5 ml/L, and K5 = coconut coir liquid smoke concentration of 10 ml/L. Observations included mortality and speed of death of Spodoptera exigua. The results showed that the concentration of coconut coir liquid smoke treatment had a significant effect on the mortality and speed of death of S. exigua. The K5 treatment (10% concentration) gave higher mortality and death rates, namely 65% and 3.77 respectively.

Does income inequality worsen pollution? The GEMS air pollution data revisited

Research on the effect of income inequality on pollution shows mixed results. This paper takes a new look at the urban air pollution data set of the U.N.‘s Global Environmental Monitoring System (GEMS). We investigate the impact of income inequality on urban air pollution and relate the results to a median-voter model. In this model, more income inequality decreases the median income, reduces pollution controls, and increases output and pollution when the median income is above a threshold. We find that income inequality, measured by the Gini coefficient, increases SO2 concentration in the rich democracies. The estimated effects are non-negligible in size. For the poor non-democracies, we find no evidence that the Gini coefficient impacts SO2 concentration. The Gini coefficient is estimated to increase the smoke concentration at the five- or ten-percent significance level in most specifications in a pooled sample. We find no evidence that the Gini coefficient impacts the concentration of particulates in a pooled sample. We conclude that the empirical results largely are consistent with the median-voter model.

Associations between smoke exposure and kidney stones: results from the NHANES (2007-2018) and Mendelian randomization analysis.

It is currently controversial whether smoke exposure is associated with the risk of kidney stones. Herein, publicly available databases were combined to explore relationships with the risk of nephrolithiasis in terms of smoking status and serum cotinine concentrations. First, we conducted an observational study using data from 2007 to 2018, based on the National Health and Nutrition Examination Survey (NHANES) database. Univariate analysis, multivariate logistic regression, trend testing, restricted cubic spline (RCS), and multiple imputation (MI) were the main analytical methods of our study. Then, A Mendelian randomization (MR) analysis was performed to explore the causal relationship between serum cotinine and nephrolithiasis. Genetic instruments for serum cotinine and pooled data for kidney stones were derived from publicly available large-scale genome-wide association studies (GWAS). Inverse-variance weighting (IVW) was the primary method for our MR analysis. A total of 34,657 and 31,352 participants were included in the observational study based on smoking status and serum cotinine concentrations, respectively. Under full adjustment of covariates, current smokers had an increased risk of kidney stones compared to non-smokers [OR = 1.17 (1.04-1.31), P = 0.009, P for trend = 0.010]. Compared with serum cotinine of <0.05 ng/ml, serum cotinine levels of 0.05-2.99 ng/ml [OR = 1.15 (1.03-1.29), P = 0.013] and ≥3.00 ng/ml [OR = 1.22 (1.10-1.37), P < 0.001] were observed to have a higher risk of nephrolithiasis (P for trend < 0.001). In addition, a non-linear relationship between log2-transformed serum cotinine and the risk of nephrolithiasis was found (P for non-linearity = 0.028). Similar results were found when serum cotinine (log2 transformation) was used as a continuous variable [OR = 1.02 (1.01-1.03), P < 0.001] or complete data was used to analyze after MI. In the MR analysis, genetically predicted high serum cotinine was causally related to the high risk of nephrolithiasis [IVW: OR = 1.09 (1.00-1.19), P = 0.044]. Current smoking and high serum cotinine concentrations may be associated with an increased risk of kidney stones. Further research is needed to validate this relationship and explore its underlying mechanisms.

Natural antimicrobial properties of liquid smoke derived from cocoa pod shells in meatball preservation

The liquid smoke, which is produced by pyrolyzing wood materials containing cellulose, hemicellulose, and lignin, can be used to preserve food. Phenolic, acetic, and carbonyl compounds found in liquid smoke can serve as a natural preservative. This study aimed to determine meatball preservation ability of liquid smoke from cocoa pod shells. Specifically, cocoa pod shells were converted to liquid smoke using slow pyrolysis at three different temperatures, 300 °C, 340 °C and 380 °C. Prior to its use, liquid smoke was purified using distillation at 190 °C. Liquid smoke at concentrations of 0.5%–3.0% was then used to preserve meatballs using an immersion method. Total volatile base-nitrogen (TVB-N), total plate count (TPC), and most probable number (MPN) analyses were used to evaluate preservation performance of liquid smoke. The statistical methods for MPN using one-way ANOVA followed by Tukey's tests. The SNI (Standar Nasional Indonesia) threshold to test whether meatballs remained fresh (TVB-N <20 mg N/g). TPC test results indicated that beef meatballs stay fresh at room temperature for 42 h or 48 h of storage using 0.5% or 1%–3% liquid smoke concentrations, respectively. Based on MPN tests showed meatballs could last for 48 h for all samples. Liquid smoke produced from cocoa pod shells can be used as a natural preservative for beef meatballs; however, liquid smoke concentrations influence the maximum preservation period for meatballs.

Projected smoke impacts from increased prescribed fire activity in California's high wildfire risk landscape

California has experienced multiple catastrophic wildfires over the last decade, fostering the need for increased forest management and understanding of the health impacts of wildfire and prescribed fire smoke. We calculated air quality impacts from past wildfires and prescribed fires and estimated how air quality may be affected under a future scenario in which prescribed fire is proposed to more than double. We merged satellite and agency records to establish a 10-year (2008–2017) baseline wildfire and prescribed fire inventory for California. Daily emissions and dispersion modeling were used to evaluate relative contributions from wildfire and prescribed fire. We scaled up prescribed burns to reach the >200,000 ha per year target, modeled over eight cycles (years) to encompass 1.6 million hectare of California Department of Forestry and Fire Prevention Priority Landscapes 4&5. We found that baseline wildfire contributes up to 20x more smoke PM2.5 concentrations than baseline prescribed fire. Target prescribed fire scenario smoke concentrations are anticipated to be ∼3x that of baseline prescribed fire. Baseline and target prescribed fire scenarios do not contribute sufficient PM2.5 to exceed air quality standards from smoke alone at the community (ZIP code) level. Baseline wildfires contribute enough PM2.5 to cause unhealthy air quality, even without contributions from ambient background PM2.5. The target prescribed fire scenario only exceeds the baseline smoke from wildfire and prescribed fire in 4% of California ZIP codes. Overall, we found that air quality is impacted significantly more from wildfires than prescribed fires, past and proposed, for the majority of California.