scholarly journals Investigation of Optimal Dilution Ratio from a Dilution Tunnel Using in Particulate Matter Measurement

2018 ◽  
Vol 5 (1) ◽  
pp. 17-33
Author(s):  
Md. Obaidullah ◽  
Bram Svend ◽  
De Ruyck Jacques
Keyword(s):  
Renewable Energy ◽  
Particulate Matter ◽  
Air Quality ◽  
Mass Flow ◽  
Measuring Instruments ◽  
Gaseous Emissions ◽  
Dilution Ratio ◽  
Porous Tube ◽  
Wide Range ◽  
Mass Flow Controllers

Combustion of fuels leads to the formation of gaseous and particulate matter pollutants that have an impact on air quality and the environment. Comparison to the gaseous emissions from stack, measuring of particulate matter (PM) needs extra attention because particles do not behave as a continuum. Dilution tunnels are used with the PM measuring instruments to dilute the hot exhaust gases leaving from the stack. The main focus of this study was to investigate the dilution ratio results obtained from a partial flow dilution tunnel. The partial flow dilution system consists of a porous tube diluter, an ejector diluter and an air heater. The dilution air flow settings into the porous tube diluter and ejector diluter are selected for a wide range of dilution ratios. Two mass flow controllers were used to regulate the flow of dilution air into the diluters. The experiments were conducted at the Renewable Energy Laboratory of the Vrije Universiteit Brussel (VUB).There were a total of fifteen experiments with four flow settings conducted. Dilution ratio (DR) is evaluated based on the ratio of the CO2 (dry) concentration in the raw sample to the diluted sample. The results obtained from the experiments with the partial flow diluters are limited between 34 and 110. The experimental results are also compared with other works and found quite similar

Particulate matter (PM10) concentration, mineralogical characteristics and traffic-related element (TRE) composition of urban traffic particles in Ibadan, Nigeria

2020 ◽  
Author(s):  
Olalekan Tesleem Kolawole ◽  
Akinade Shadrach Olatunji ◽  
Khanneh Wadinga Fomba
Keyword(s):  
Particulate Matter ◽  
Air Quality ◽  
Quality Index ◽  
Mineralogical Composition ◽  
Air Quality Index ◽  
Engine Oil ◽  
Emission Spectrometry ◽  
Rural Roads ◽  
Wide Range ◽  
National Highway

<p>Atmospheric traffic-related elements (TRE) generated from traffic-related emissions have been linked to a wide range of human diseases and also affect the ecosystem. This study focuses on data from the Nigerian air quality network along the segment of the National Highway Roads (NHR), inner-city Major Roads (MR) and Rural Roads (RR) in Ibadan. The aim of this near-road monitoring was to assess the levels of TRE, determine the particulate matter (PM<sub>10</sub>) concentrations and mineralogical composition of the PM<sub>10</sub> particles.</p><p>Sixty particulate matter (PM<sub>10</sub>) samples were collected from 5 traffic-related stations (2-NHR; 2-MR; 1-RR) (six samples from each station) in the study area using traffic-related high-volume air sampler with PM<sub>10</sub> cut-off on cellulose filter. PM<sub>10</sub> concentration was calculated from the difference in weight of the filter and flow rate of the sampler while the mineralogical composition of the PM<sub>10</sub> was determined by single-particle analysis using scanning electron microscopy and energy-dispersive x-ray spectroscopy (SEM/EDXS) techniques, and the TRE were determined by inductively coupled plasma-optical emission spectrometry (ICP-OES).</p><p>The results of the PM<sub>10</sub> concentration showed that NHR had the highest concentration of 1194.30 µg/m<sup>3</sup>, while the lowest concentration was observed in RR (36.33 µg/m<sup>3</sup>), these correspond to the level of traffic density in both stations, the former having 60,000 vehicle/day while the later had <2000 vehicle/day. More than 80% of the PM<sub>10</sub> concentrations in the NHR and the MR were classified as being unhealthy-hazardous to humans living very close to this environment on the basis of the air quality index (AQI). The most abundant mineral particles were clay (53%), quartz (9%) and rock-forming minerals (<3%) sourced from roadside soil and fly ash from construction rock dust. Other particles such as clay+sulphate (17%), sulphur-rich particle (8%), soot (7%) and tarballs (8%) were generated from anthropogenic input from traffic-related activities. The highest average concentration of TRE such as Ba, Cd, La, Pb, V and Zn (2.81, 1.61, 1.21, 6.92, 8.92 and 10.73 respectively all in µg/m<sup>3</sup>) was observed in NHR, while those of Cu, Mo and Mn (5.45 µg/m<sup>3</sup>, 6.67 µg/m<sup>3</sup> and 11.78 µg/m<sup>3</sup> respectively) was observed in MR. Principal component analysis (PCA) revealed four factors (PC1 to PC4). In PC1 26.57% of the variability was observed and loaded with Ba (0.76), Pb (0.82), V (0.85) while PC 2 could explain 17.94% variability and had La (0.67), Mn (0.83) and Mo (0.68), PC 3 explained 15.91% variance loaded with Cd (0.84) and Zn (0.77), and PC 4 gave account of 13.83% of the variance and was loaded with Cu (0.86). PC1 and PC2 were products of both gasoline and diesel engine while PC3 and PC4 were generated from engine oil, brake and tyre wares. The calculated enrichment factor classified the TRE as being moderate to highly contaminated in both NHR and MR while RR was considered relatively uncontaminated.</p><p> </p><p>Keywords: Traffic-related elements; Air quality index; National highway roads; Major roads; Rural roads</p>

scholarly journals Silicone tube humidity generator

2021 ◽  
Author(s):  
Robert Berg ◽  
Nicola Chiodo ◽  
Eric Georgin
Keyword(s):  
Mass Flow ◽  
Unsaturated Flow ◽  
Low Cost ◽  
Mixing Ratio ◽  
Silicone Tube ◽  
Humidity Generator ◽  
Wide Range ◽  
Complete Test ◽  
Mass Flow Controllers ◽  
Flow Controllers

Abstract. We describe the model and construction of a two-flow (or divided-flow) humidity generator, developed at LNE-CNAM, that uses mass flow controllers to mix a stream of dry gas with a stream of humid gas saturated at 28 °C. It can generate a wide range of humidity, with mole fractions in the range 0.7 × 10−6 < x < 9000 × 10−6, without using low temperature or high pressure. This range is suitable for calibrating balloon-borne instruments that measure humidity in the stratosphere, where x ~5 × 10−6. The generator’s novel feature is a saturator that comprises 5 m of silicone tubing immersed in water. Water enters the humid gas stream by diffusing through the wall of the tubing until the gas stream flowing through the tubing is saturated. This design provides a simple, low-cost humidity generator with an accuracy that is acceptable for many applications. The key requirement is that the tubing be long enough to ensure saturation, so that the saturator’s output is independent of the dimensions and permeability of the tube. A length of only a few meters was sufficient because the tube was made of silicone; other common polymers have permeabilities that are 1000 times smaller. We verified the model of the transition from unsaturated flow to saturated flow by measuring the humidity while using three tube lengths, two of which were too short for saturation. As a more complete test, we used the generator as a primary device after correcting the calibrations of the mass flow controllers that determined the mixing ratio. At mole fractions 50 × 10−6 < x < 5000 × 10−6, the generator’s output mole fraction xgen agreed to within 1 % with the value xcm measured by a calibrated chilled-mirror hygrometer; in other words, their ratio fell in the range xgen/xcm = 1.00 ± 0.01. At smaller mole fractions, their differences fell in range xgen − xcm = ±1 × 10−6.

Evaluation of the accuracy indicators in determination of the coating thickness by crater grinding method

2020 ◽  
Vol 86 (7) ◽  
pp. 39-44
Author(s):  
K. V. Gogolinsky ◽  
A. E. Ivkin ◽  
V. V. Alekhnovich ◽  
A. Yu. Vasiliev ◽  
A. E. Tyurnina ◽  
...  
Keyword(s):  
Coating Thickness ◽  
Functional Dependence ◽  
Measurement Procedure ◽  
Metrological Certification ◽  
Measuring Instruments ◽  
Properties Of Coatings ◽  
Special Equipment ◽  
Grinding Method ◽  
Accuracy Of Measurements ◽  
Wide Range

Thickness is one of the key indicators characterizing the quality and functional properties of coatings. Various indirect methods (electromagnetic, radiation, optical) most often used in practice to measure thickness are based on the functional dependence of a particular physical parameter of the system «base – coating» on the coating thickness. The sensitivity of these procedures to the certain properties of coatings imposes the main restriction to the accuracy of measurements. Therefore, the development and implementation of the approaches based on direct measurements of geometric parameters of the coating appears expedient. These methods often belong to the class of «destructive» and, in addition to measuring instruments, require the use of special equipment. To ensure the uniformity of measurements in the laboratory or technological control, these methods are isolated as a separate procedure (method) and must undergo metrological certification in accordance with GOST R 8.563–2009. We present implementation, metrological certification and practical application of the method for measuring thickness of coatings by crater-grinding method. The principles of technical implementation of test equipment, measurement procedure and calculation formulas are described. The results of evaluating the accuracy indicators of the proposed procedure by calculation and experimental methods are presented. In both cases, the relative error did not exceed 6%. The applicability of the developed technique is shown for a wide range of coating materials (from soft metals to superhard ceramics) of different thickness (with from units to hundreds of micrometers). Apart from the goals of process control and outgoing inspection, the method can be recommended as a reference measurement procedure for calibration of measures and adjusting samples for various types of thickness gauges.

scholarly journals The impact of measures to reduce ambient air PM<sub>10</sub> concentrations originating from road dust, evaluated for a street canyon in Helsinki

2019 ◽  
Vol 19 (17) ◽  
pp. 11199-11212 ◽  
Author(s):  
Ana Stojiljkovic ◽  
Mari Kauhaniemi ◽  
Jaakko Kukkonen ◽  
Kaarle Kupiainen ◽  
Ari Karppinen ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Air Quality ◽  
Street Canyon ◽  
Dust Emission ◽  
Road Dust ◽  
Ambient Air ◽  
Air Quality Measurements ◽  
Emission Models ◽  
The Impact ◽  
Quality Measurements

Abstract. We have numerically evaluated how effective selected potential measures would be for reducing the impact of road dust on ambient air particulate matter (PM10). The selected measures included a reduction of the use of studded tyres on light-duty vehicles and a reduction of the use of salt or sand for traction control. We have evaluated these measures for a street canyon located in central Helsinki for four years (2007–2009 and 2014). Air quality measurements were conducted in the street canyon for two years, 2009 and 2014. Two road dust emission models, NORTRIP (NOn-exhaust Road TRaffic Induced Particle emissions) and FORE (Forecasting Of Road dust Emissions), were applied in combination with the Operational Street Pollution Model (OSPM), a street canyon dispersion model, to compute the street increments of PM10 (i.e. the fraction of PM10 concentration originating from traffic emissions at the street level) within the street canyon. The predicted concentrations were compared with the air quality measurements. Both road dust emission models reproduced the seasonal variability of the PM10 concentrations fairly well but under-predicted the annual mean values. It was found that the largest reductions of concentrations could potentially be achieved by reducing the fraction of vehicles that use studded tyres. For instance, a 30 % decrease in the number of vehicles using studded tyres would result in an average decrease in the non-exhaust street increment of PM10 from 10 % to 22 %, depending on the model used and the year considered. Modelled contributions of traction sand and salt to the annual mean non-exhaust street increment of PM10 ranged from 4 % to 20 % for the traction sand and from 0.1 % to 4 % for the traction salt. The results presented here can be used to support the development of optimal strategies for reducing high springtime particulate matter concentrations originating from road dust.

scholarly journals Effects of urban atmospheric particulate matter on higher plants using Lycopersicon esculentum as model species

2021 ◽  
Vol 3 (9) ◽  
Author(s):  
Katalin Hubai ◽  
Nora Kováts ◽  
Gábor Teke
Keyword(s):  
Particulate Matter ◽  
Lycopersicon Esculentum ◽  
Protein Content ◽  
Higher Plants ◽  
Nutrient Content ◽  
Atmospheric Particulate Matter ◽  
Dose Effect ◽  
Atmospheric Particulate ◽  
Wide Range ◽  
Treatment Experiment

AbstractAtmospheric particulate matter (PM) is one of the major environmental concerns in Europe. A wide range of studies has proved the ecotoxic potential of atmospheric particles. PM exerts chemical stress on vegetation by its potentially toxic constituents; however, relatively few studies are available on assessing phytotoxic effects under laboratory conditions. In our study, aqueous extract of particulate matter was prepared and used for treatment. Experiment was following the procedure defined by the No. 227 OECD Guideline for the Testing of Chemicals: Terrestrial Plant Test. Tomato (Lycopersicon esculentum Mill.) plants were used; elucidated toxicity was assessed based on morphological and biochemical endpoints such as biomass, chlorophyll-a and chlorophyll-b, carotenoids, and protein content. Biomass reduction and protein content showed a clear dose–effect relationship; the biomass decreased in comparison with the control (100%) in all test groups (TG) at a steady rate (TG1: 87.73%; TG2: 71.77%; TG3: 67.01%; TG4: 63.63%). The tendency in protein concentrations compared to the control was TG1: 113.61%; TG2: 148.21% TG3: 160.52%; TG4: 157.31%. However, pigments showed a ‘Janus-faced’ effect: nutrient content of the sample caused slight increase at lower doses; actual toxicity became apparent only at higher doses (chlorophyll-a concentration decrease was 84.47% in TG4, chlorophyll-b was 77.17%, and finally, carotene showed 83.60% decrease in TG4).

scholarly journals Spatial Analysis (Measurements at Heights of 10 m and 20 m above Ground Level) of the Concentrations of Particulate Matter (PM10, PM2.5, and PM1.0) and Gaseous Pollutants (H2S) on the University Campus: A Case Study

Atmosphere ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 62
Author(s):  
Robert Cichowicz ◽  
Maciej Dobrzański
Keyword(s):  
Spatial Distribution ◽  
Hydrogen Sulfide ◽  
Particulate Matter ◽  
Air Quality ◽  
Spatial Analysis ◽  
Ground Level ◽  
Leeward Side ◽  
High Concentration ◽  
Above Ground Level ◽  
High Concentrations

Spatial analysis of the distribution of particulate matter PM10, PM2.5, PM1.0, and hydrogen sulfide (H2S) gas pollution was performed in the area around a university library building. The reasons for the subject matter were reports related to the perceptible odor characteristic of hydrogen sulfide and a general poor assessment of air quality by employees and students. Due to the area of analysis, it was decided to perform measurements at two heights, 10 m and 20 m above ground level, using measuring equipment attached to a DJI Matrice 600 unmanned aerial vehicle (UAV). The aim of the measurements was air quality assessment and investigate the convergence of the theory of air flow around the building with the spatial distribution of air pollutants. Considerable differences of up to 63% were observed in the concentrations of pollutants measured around the building, especially between opposite sides, depending on the direction of the wind. To explain these differences, the theory of aerodynamics was applied to visualize the probable airflow in the direction of the wind. A strong convergence was observed between the aerodynamic model and the spatial distribution of pollutants. This was evidenced by the high concentrations of dust in the areas of strong turbulence at the edges of the building and on the leeward side. The accumulation of pollutants was also clearly noticeable in these locations. A high concentration of H2S was recorded around the library building on the side of the car park. On the other hand, the air turbulence around the building dispersed the gas pollution, causing the concentration of H2S to drop on the leeward side. It was confirmed that in some analyzed areas the permissible concentration of H2S was exceeded.

scholarly journals Indoor Air Quality: Assessment of Dangerous Substances in Incense Products

2021 ◽  
Vol 18 (15) ◽  
pp. 8086
Author(s):  
Gabriela Ventura Silva ◽  
Anabela O. Martins ◽  
Susana D. S. Martins
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Indoor Air Pollution ◽  
Gaseous Emissions ◽  
Limit Values ◽  
Cone Type ◽  
Guideline Values ◽  
Taking Action ◽  
At Home

Indoor air pollution has obtained more attention in a moment where “stay at home” is a maximum repeated for the entire world. It is urgent to know the sources of pollutants indoors, to improve the indoor air quality. This study presents some results obtained for twelve incense products, used indoors, at home, and in temples, but also in spa centers or yoga gymnasiums, where the respiratory intensity is high, and the consequences on health could be more severe. The focus of this study was the gaseous emissions of different types of incense, performing a VOC screening and identifying some specific VOCs different from the usual ones, which are known or suspected to cause severe chronic health effects: carcinogenic, mutagenic, and reprotoxic. Thirteen compounds were selected: benzene, toluene, styrene, naphthalene, furfural, furan, isoprene, 2-butenal, phenol, 2-furyl methyl ketone, formaldehyde, acetaldehyde, and acrolein. The study also indicated that incense cone type shows a higher probability of being more pollutant than incense stick type, as from the 12 products tested, four were cone type, and three of them were in the group of the four higher polluters. Benzene and formaldehyde presented worrying levels in the major part of the products, above guideline values established by the WHO. Unfortunately, there are no limit values established for indoor air for all the compounds studied, but this fact should not exempt us from taking action to alert the population to the potential dangers of using those products. From this study, acetaldehyde, acrolein, furfural, and furan emerge as compounds with levels to deserve attention.

scholarly journals The Diamond League athletic series: does the air quality sparkle?

2021 ◽  
Author(s):  
James R. Hodgson ◽  
Lee Chapman ◽  
Francis D. Pope
Keyword(s):  
Particulate Matter ◽  
Air Quality ◽  
Performance Metrics ◽  
Urban Air Pollution ◽  
Quality Data ◽  
Performance Variation ◽  
Short And Long Term ◽  
Respiratory Conditions ◽  
Race Performance

AbstractUrban air pollution can have negative short- and long-term impacts on health, including cardiovascular, neurological, immune system and developmental damage. The irritant qualities of pollutants such as ozone (O3), nitrogen dioxide (NO2) and particulate matter (PM) can cause respiratory and cardiovascular distress, which can be heightened during physical activity and particularly so for those with respiratory conditions such as asthma. Previously, research has only examined marathon run outcomes or running under laboratory settings. This study focuses on elite 5-km athletes performing in international events at nine locations. Local meteorological and air quality data are used in conjunction with race performance metrics from the Diamond League Athletics series to determine the extent to which elite competitors are influenced during maximal sustained efforts in real-world conditions. The findings from this study suggest that local meteorological variables (temperature, wind speed and relative humidity) and air quality (ozone and particulate matter) have an impact on athletic performance. Variation between finishing times at different race locations can also be explained by the local meteorology and air quality conditions seen during races.

scholarly journals Spatial and Temporal Characteristics of Environmental Air Quality and Its Relationship with Seasonal Climatic Conditions in Eastern China during 2015–2018

2021 ◽  
Vol 18 (9) ◽  
pp. 4524
Author(s):  
Zhiyuan Wang ◽  
Xiaoyi Shi ◽  
Chunhua Pan ◽  
Sisi Wang
Keyword(s):  
Particulate Matter ◽  
Air Quality ◽  
Air Pollutants ◽  
Large Scale ◽  
Asian Summer Monsoon ◽  
Eastern China ◽  
Climatic Conditions ◽  
Uniform Structure ◽  
Concentration Limit ◽  
Environmental Air

Exploring the relationship between environmental air quality (EAQ) and climatic conditions on a large scale can help better understand the main distribution characteristics and the mechanisms of EAQ in China, which is significant for the implementation of policies of joint prevention and control of regional air pollution. In this study, we used the concentrations of six conventional air pollutants, i.e., carbon monoxide (CO), sulfur dioxide (SO2), nitrogen dioxide (NO2), fine particulate matter (PM2.5), coarse particulate matter (PM10), and ozone (O3), derived from about 1300 monitoring sites in eastern China (EC) from January 2015 to December 2018. Exploiting the grading concentration limit (GB3095-2012) of various pollutants in China, we also calculated the monthly average air quality index (AQI) in EC. The results show that, generally, the EAQ has improved in all seasons in EC from 2015 to 2018. In particular, the concentrations of conventional air pollutants, such as CO, SO2, and NO2, have been decreasing year by year. However, the concentrations of particulate matter, such as PM2.5 and PM10, have changed little, and the O3 concentration increased from 2015 to 2018. Empirical mode decomposition (EOF) was used to analyze the major patterns of AQI in EC. The first mode (EOF1) was characterized by a uniform structure in AQI over EC. These phenomena are due to the precipitation variability associated with the East Asian summer monsoon (EASM), referred to as the “summer–winter” pattern. The second EOF mode (EOF2) showed that the AQI over EC is a north–south dipole pattern, which is bound by the Qinling Mountains and Huaihe River (about 35° N). The EOF2 is mainly caused by seasonal variations of the mixed concentration of PM2.5 and O3. Associated with EOF2, the Mongolia–Siberian High influences the AQI variation over northern EC by dominating the low-level winds (10 m and 850 hPa) in autumn and winter, and precipitation affects the AQI variation over southern EC in spring and summer.

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