Cooking can release high concentrations of different air pollutants indoors, including particulate matter, polycyclic aromatic hydrocarbons (PAHs), and other gaseous pollutants such as volatile ...organic compounds (VOCs), oxides of carbon (CO
x
), and oxides of nitrogen (NO
x
). Although some reviews have been conducted on emissions from cooking, they have not paid specific attention to Chinese cooking. Subsequent research, however, has focused on this aspect. We collected literature from 1995 to 2016 and summarized air pollutant emissions from Chinese cooking. We analyzed the characteristics of such pollutants based on different influential factors. It was found that the cooking method could have a predominant impact on emissions from Chinese cooking, and oil-based cooking produces air pollutants at much higher levels than water-based cooking. In addition, the use of gas stoves released more pollutants than electric stoves. Furthermore, the type and temperature of oil could have caused disparity in source strengths from the oil heating process. Ventilation patterns or the operation mode of range hoods could control indoor pollution levels. With more information focused on Chinese cooking emissions, we can propose more effective strategies for improving the indoor air environment in China.
Household air pollution generated from cooking is severe, especially for Chinese-style cooking. We measured the emission rates of multiple air pollutants including fine particles (PM2.5), ultrafine ...particles (UFPs), and volatile organic compounds (VOCs, including formaldehyde, benzene, and toluene) that were generated from typical Chinese cooking in a residential kitchen. The experiment was designed through five-factor and five-level orthogonal testing. The five key factors were cooking method, ingredient weight, type of meat, type of oil, and meat/vegetable ratio. The measured emission rates (mean value ± standard deviation) of PM2.5, UFPs, formaldehyde, total volatile organic compounds (TVOCs), benzene, and toluene were 2.056 ± 3.034 mg/min, 9.102 ± 6.909 × 1012 #/min, 1.273 ± 0.736 mg/min, 1.349 ± 1.376 mg/min, 0.074 ± 0.039 mg/min, and 0.004 ± 0.004 mg/min. Cooking method was the most influencing factor for the emission rates of PM2.5, UFPs, formaldehyde, TVOCs, and benzene but not for toluene. Meanwhile, the emission rate of PM2.5 was also significantly influenced by ingredient weight, type of meat, and meat/vegetable ratio. Exhausting the range hood decreased the emission rates by approximately 58%, with a corresponding air change rate of 21.38/h for the kitchen room.
Cooking is an important source of air pollutants in Chinese residences. Cooking emissions are influenced by many factors, among which oil temperature is one of the most influential. In this study, 15 ...typical Chinese dishes, prepared using oil-based cooking methods (stir-, pan- and deep-frying), were chosen. The experiment was repeated three times with each dish—freshly prepared for each subsequent analysis—considering five key factors, to determine the emission rates of fine particulate matter (PM2.5), ultrafine particles (UFPs), formaldehyde, and total volatile organic compounds (TVOC). The oil temperature and oil consumption were measured. A partial correlation analysis was performed to identify the influence of oil temperature on air pollutant emission rates during Chinese residential cooking. The zero-order correlation coefficients for all air pollutants, excluding UFPs, and partial correlation coefficients for all air pollutants, were not significant, implying that the influence of oil temperature on air pollutant emission rates was not significant, because practical peak oil temperatures (112–177 °C) were mostly below the oil smoke point (107–234 °C).
•Cooking 15 typical Chinese dishes were repeated 3 times.•Emission rates of PM2.5, UFPs, VOCs and oil temperatures were measured.•Correlation between oil temperature and emission rate was analyzed.•The influence of oil temperature on emission rates was not so significant.
The ability of the projectile to strike accurately in the air depends on the accurate measurement of its flight distance. Due to the influence of the external environment, it is very difficult to ...measure the distance of high-speed projectiles in real time with ranging equipment such as radar and laser. Based on this, a real-time measurement model of the horizontal flight distance of the projectile was designed, which combines trajectory equation and discrete acceleration. First, the angle of inclination of the projectile at each position was calculated according to the six-degree-of-freedom rigid outer trajectory model. Then, two kinds of distance measurement models based on discrete acceleration integration were introduced, and the accuracy simulation was carried out. Simulation results show that the Simpson integral method is more accurate. The flight arc length of the projectile was calculated by the Simpson integral method. Finally, the horizontal flight distance of the projectile was obtained by combining the flight arc length and inclination angle of the projectile. Finally, the flight distance measurement model was simulated, and the simulation results show that the model has high accuracy. The simulation results show that the horizontal flight distance of the projectile can be measured by the trajectory equation and discrete acceleration according to the set conditions. This method can be used to measure the distance of the projectile by carrying the sensor and is less affected by the external environment. It can provide a theoretical basis and reference for the measurement of the horizontal distance of the projectile.
This paper reports a novel infrared focal plane array (FPA) using SiNx/SiO2/SiNx sandwiched structure as the supporting frames for bimaterial cantilever pixels. The device was fabricated by a bulk ...silicon process, where a trench backfill technique was employed to form the SiNx/SiO2/SiNx sandwiched frames. By replacing the silicon frame with SiNx/SiO2/SiNx sandwiched frame, the fill factor of the FPA is increased to 42%. Compared with other substrate-free FPAs with frames making of a thin layer of SiNx, the sandwiched frame provides more supporting strength for the cantilever pixels. Meanwhile, the reliability and the uniformity of the FPA were improved with a design of staggered arrangement of cantilever pixels. Thermal images of human bodies were captured successfully at room temperature. A complete analysis of device performance was also carried out both theoretically and experimentally, including thermomechanical sensitivity, noise equivalent temperature difference, and response time.
The chemical composition of fine particulate matter (PM2.5) emitted during cooking such as polycyclic aromatic hydrocarbons (PAHs), chemical elements (especially heavy metals), organic carbon (OC), ...and elemental carbon (EC) are of great concern to human health in China. We collected five duplicate sets of samples of cooking emissions from a Chinese residential kitchen for the five most common cooking methods based on orthogonal design. Emission rates and concentrations of PM2.5-bound chemicals, including 16 PAHs, 21 elements, OC, and EC, were determined based on the corresponding mass fraction of species in PM2.5. The chemical profile of PM2.5 varied according to the cooking method. The results indicated that OC was the dominant component of the fine emitted particles and the emission rates ranged from 27.87 μg/min to 1916.68 μg/min. In comparison, the emission rates of EC ranged from 2.02 μg/min to 29.47 μg/min. The emission rates of the elements varied between 0.01 ng/min and 9.57 μg/min and S, Ca, Na, K, Al, Mg, and Fe were the most abundant elements in cooking profiles. The total emission rates of the 16 PAHs in PM2.5 ranged between 8.83 ng/min and 241.06 ng/min and Nap, Pyr, Chr, BghiP, and Phe were the main PAHs released from residential cooking. Thereinto, Nap and Phe could be utilized as organic markers to distinguish between cooking and other non-cooking source emissions. These findings could assist in the determination of the concentrations of PM2.5-bound chemicals in regard to emission control strategies, as well as in the assessment of health risks.
Display omitted
•Emission rates of PM2.5-bound chemical from Chinese cooking were measured.•Five typical Chinese cooking methods were studied by an orthogonal test design.•Chemical profile including 21 elements, 16 PAHs, OC, and EC were determined.•The findings can guide engineering control strategies and exposure assessment.
Residential Chinese cooking can lead to severe exposure to carcinogenic fine particles (PM2.5) from cooking-oil fumes. Keeping the kitchen door open is conducive to improving air quality in the ...kitchen, but it can result in further diffusion of PM2.5 emissions into adjacent rooms. In this study, PM2.5 exposure concentrations were measured in the kitchen and an adjacent room during and after cooking activities, where various interventions were employed based on an orthogonal design. Intervention strategies, including range-hood operations, protective respirator use, personal portable fan operation, side panels configured for the range hood, and air cleaner use, were incorporated. The results demonstrated that using the range hood with an equivalent air exchange rate of 7.5–10.9 h−1 in the kitchen and wearing respirators during cooking were the most efficient prevention measures, significantly decreasing the inhalation exposure to PM2.5 for the cook in the kitchen by 90–95% and 79–84%, respectively. The average concentrations in the adjacent living room could be decreased by 50%–75% with an additional period of 5–10 min running the range hood or the air cleaner (the cleaner air exchange rate was no more than 5 h−1).
Display omitted
•Inhalation exposure to PM2.5 from residential Chinese cooking was measured.•Effects of various low-cost interventions were studied by an orthogonal test design.•The findings can guide Chinese residents to protect from cooking-related PM2.5 exposure.
The household second hand smoke problem is still severe in China due to the large number of smokers and the prevalence of smoking at home. We selected ten Chinese cigarettes, including seven ...best-selling products of different brands and three types of products of the same popular brand, to measure the emission rates of ultrafine particles (UFPs: particulate matter with diameter less than 0.1 μm) and fine particles (PM2.5: particulate matter with aerodynamic diameter less than 2.5 μm) with the help of two habitual smokers. The emission rate of UFPs generated from smoking popular Chinese cigarettes was 2.51 ± 0.50 × 1012 #/min or 1.98 ± 0.30 × 1013 #/cigarette, and the emission rate of PM2.5 was 2.25 ± 0.39 mg/min or 17.63 ± 1.56 mg/cigarette. The emission rates of UFPs and PM2.5 from Virginia-type cigarettes were higher than those from blended-type and exotic flavor-type cigarettes of the same brand. The emission rates of UFPs and PM2.5 from Chinese cigarettes were higher than those from Western cigarettes. The measured UFPs and PM2.5 emission rates from human smoking of Chinese cigarettes can be used to assess the population exposure and design control measures in residences.
Display omitted
•UFP and PM2.5 emissions from human smoking of Chinese cigarettes were measured.•The studied cigarette types account for 98% of Chinese cigarettes.•Emissions from Chinese cigarettes are higher than those from Western cigarettes.•Emissions from Virginia-type cigarettes are higher than those from other types.•These findings can guide engineering control strategies and exposure assessment.
Development of efficient hydrogen refueling station (HRS) is highly desirable to reduce the hydrogen cost and hence the life cycle expense of fuel cell vehicles (FCVs), which is hindering the large ...scale application of hydrogen mobility. In this work, we demonstrate the optimization of gaseous HRS process and control method to perform fast and efficient refueling, with reduced energy consumption and increased daily fueling capacity. The HRS was modeled with thermodynamics using a numerical integration method and the accuracy for hydrogen refueling simulation was confirmed by experimental data, showing only 2 °C of temperature rise deviation. The refueling protocols for heavy duty FCVs were first optimized, demonstrating an average fueling rate of 2 kg/min and pre-cooling demand of less than 7 kW for 35 MPa type III tanks. Fast refueling of type IV tanks results in more significant temperature rise, and the required pre-cooling temperature is lowered by 20 K to achieve comparable fueling rate. The station process was also optimized to improve the daily fueling capacity. It is revealed that the hydrogen storage amount is cost-effective to be 25–30% that of the nominal daily refueling capacity, to enhance the refueling performance at peak time and minimize the start and stop cycles of compressor. A novel control method for cascade replenishment was developed by switching among the three banks in the order of decreased pressure, and results show that the daily refueling capacity of HRS is increased by 5%. Therefore, the refueling and station process optimization is effective to promote the efficiency of gaseous HRS.
•Refueling protocols for heavy-duty vehicles optimized with reduced energy consumption.•Station storage is revealed favorable at 25–30% of designed daily refueling capacity.•Novel replenishment method for cascade leads to daily refueling capacity increased by 5%.
Radical measures for controlling ambient air pollution sources were employed by the Chinese government during the Asia-Pacific Economic Cooperation (APEC) meeting in 2014, providing a unique case to ...evaluate the health effect benefits from such measures. To examine the cancer risk reduction from the source control measures during the APEC meeting, we estimated the reduction in population exposure to PM2.5 and PAHs and the reduction in PAHs-associated cancer risk if the control measures were sustained over time. We determined the population exposure to PM2.5 and PM2.5-bound PAHs for the 21.52 million Beijing residents using a Land Use Regression model to determine the spatial distribution of PM2.5 and a Monte Carlo approach to revise indoor/outdoor infiltration factor and time activity patterns. Into the model and approach, we incorporated the spatial variance and indoor/outdoor differences in the PM2.5 and PM2.5-bound PAHs concentrations, based on measurements. We then estimated lung cancer risk using the population attributable fraction (PAF), assuming the control measures were sustained over time. The mean PM2.5 exposure concentration decreased from 37.5 μg/m3 (CI:17.1–74.9 μg/m3) to 24.0 μg/m3 (CI:10.2–47.7 μg/m3), whereas the mean PM2.5-bound equivalent benzoapyrene (BaPeq) exposure concentration decreased from 7.1 ng/m3 (CI:3.3–14.2 ng/m3) to 4.2 ng/m3 (CI:1.8–7.7 ng/m3), resulting in a reduction in the lung cancer PAF from 0.75% to 0.45%, if the measures were sustained over time.
Display omitted
•Synchronous indoor and outdoor concentrations of PM2.5-bound PAHs were measured.•The LUR model was employed to obtain the spatial distribution of PM2.5 and PM2.5-bound PAHs concentrations.•The Monte Carlo approach was employed to determine population exposure.•We estimated the PAF of lung cancer risk based on TEFs.
The source control measures employed during the APEC meeting could reduce the inhalation cancer risk if the measures are sustained over time.
