scholarly journals Gaseous and Particulate Emissions of a Euro 4 Motorcycle and Effect of Driving Style and Open or Closed Sampling Configuration

2020 ◽  
Vol 12 (21) ◽  
pp. 9122
Author(s):  
Barouch Giechaskiel
Keyword(s):  
Air Pollution ◽  
Gaseous Pollutants ◽  
Particulate Emissions ◽  
Passenger Cars ◽  
Relative Contribution ◽  
Transfer Tube ◽  
Significant Difference ◽  
Total Particle ◽  
Order Of Magnitude ◽  
Main Message

Air pollution remains a serious concern for European citizens. The relative contribution of mopeds and motorcycles to air pollution started to increase as the levels from other vehicles started to decrease. The information on emission levels of Euro 4 motorcycles is limited because they were only recently introduced into the market (2016). In this study, the emissions of a 1 L Euro 4 motorcycle were determined with two drivers and two different sampling configurations (i.e., open or closed transfer tube to the dilution tunnel; both allowed in the current regulation). The motorcycle respected the current Euro 4 limits and even the future Euro 5 limits for most pollutants (CO 600 mg/km, NOx 48 mg/km, total hydrocarbons 60 mg/km). The particulate emissions, which are not regulated for this category of vehicles, were also very low and fulfilled the current limits of passenger cars (particulate mass < 0.5 mg/km, particle number 3 × 1011 p/km). The total particle emissions (i.e., including volatiles) were also low with the open configuration (6 × 1011 p/km). They increased more than one order of magnitude with the closed configuration due to desorption of deposited material from the transfer tube. For the gaseous pollutants, there was no significant difference between open or closed configuration (CO2 within 0.3%, rest pollutants 10%), but they were different between the two drivers (CO2 1.3%, rest pollutants 25%–50%). The main message from this work is that open and closed configurations are equivalent for gaseous pollutants but the open should be used when particles are measured.

scholarly journals Particle emissions of a TDI-engine with different lubrication oils

2005 ◽  
Vol 121 (2) ◽  
pp. 46-55
Author(s):  
J. CZERWINSKI ◽  
J.-L. PÉTERMANN ◽  
A. ULRICH ◽  
G. MUELLER ◽  
A. WICHSER
Keyword(s):  
Particle Filter ◽  
Fine Particles ◽  
Particulate Emissions ◽  
Passenger Cars ◽  
Diesel Particle Filter ◽  
Particle Emissions ◽  
Lubrication Oil ◽  
Total Particle ◽  
Lubrication Oils ◽  
Ultra Fine Particles

Due to increasing concern about health effects of fine and ultra-fine particles (nanoparticles) from combustion engines, the diesel particle filter technology (DPF) was extensively introduced to heavy duty and passenger cars in the last years. In this respect, a very important parameter is the irreversible plugging of the DPF with non-combustible ashes. The quality of lubrication oil, especially the ash content has a certain influence on regeneration intervals of diesel particle filters. In the present study, the effects of different lubrication oils on particle mass and nano-particle size distribution were investigated. The test engine was a modern diesel engine without particle filter system. A main goal was to find out, how different lubrication oils influence the particulate emissions and the contribution of oil to total particle emissions. Moreover, first results of a tracing study will be discussed. The comparison of a non-doped lubrication oil with a doped oil should enlighten the contribution of the oil to the particle formation. It has been shown that beside sulphur content the particle emission is also effected by the composition (e.g. additive packages) of the oils.

AWARENESS ABOUT INDOOR AIR POLLUTION IN GENERAL POPULATION OF RAWALPINDI AND ISLAMABAD

2018 ◽  
Vol 8 (2) ◽  
pp. 80-83
Author(s):  
Nadia Tariq ◽  
Tamkeen Jaffry ◽  
Rahma Fiaz ◽  
Abdul Majid Rajput ◽  
Sadaf Khalid
Keyword(s):  
Air Pollution ◽  
General Population ◽  
Indoor Air ◽  
Indoor Air Pollution ◽  
Economic Status ◽  
Educational Status ◽  
Epidemiological Studies ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Significant Difference

Background: Indoor air pollutants are increasingly being associated with respiratory illnesses leading to high degree of morbidity and mortality. There are not sufficient epidemiological studies from Pakistan which assess level of awareness of indoor air pollution resulting in respiratory diseases in population. Methods: This cross sectional survey was carried out on general population of Rawalpindi/Islamabad. Sample size was 223 study subjects selected by non-probability convenient sampling. Knowledge of the study subjects was determined with regard to indoor air pollution, its effects on health and different sources of indoor air pollution with the help of a questionnaire. The influence of age, gender, educational status and socio economic status on the level of awareness was also analyzed. Results: Out of total 223 participants, 115 were males and108 females. Participants aware of indoor air pollution were 91.5% and adequate awareness about its sources was 80.7%. Those who knew indoor air pollution is detrimental to health were 95.1%. Awareness about building construction dust as source of indoor air pollution was maximum (84.8%). There was significant difference in awareness among participants with different monthly incomes and educational status and also between males and females. Conclusion: This study concludes that general population of Rawalpindi/Islamabad has fairly good awareness about sources of indoor air pollution. Use of harmful material causing indoor air pollution should be limited or substituted with better ones where possible.

Non-stationary process characteristics of the gas outflow into a liquid

2019 ◽  
Vol 14 (2) ◽  
pp. 82-88
Author(s):  
M.V. Alekseev ◽  
I.S. Vozhakov ◽  
S.I. Lezhnin
Keyword(s):  
Numerical Simulation ◽  
Liquid Column ◽  
Gas Content ◽  
Liquid Lead ◽  
Gas Flows ◽  
Asymptotic Model ◽  
Process Characteristics ◽  
Significant Difference ◽  
Order Of Magnitude ◽  
Volume Method

A numerical simulation of the process of the outflow of gas under pressure into a closed container partially filled with liquid was carried out. For comparative theoretical analysis, an asymptotic model was used with assumptions about the adiabaticity of the gas outflow process and the ideality of the liquid during the oscillatory one-dimensional motion of the liquid column. In this case, the motion of the liquid column and the evolution of pressure in the gas are determined by the equation of dynamics and the balance of enthalpy. Numerical simulation was performed in the OpenFOAM package using the fluid volume method (VOF method) and the standard k-e turbulence model. The evolution of the fields of volumetric gas content, velocity, and pressure during the flow of gas from the high-pressure chamber into a closed channel filled with liquid in the presence of a ”gas blanket“ at the upper end of the channel is obtained. It was shown that the dynamics of pulsations in the gas cavity that occurs when the gas flows into the closed region substantially depends on the physical properties of the liquid in the volume, especially the density. Numerical modeling showed that the injection of gas into water occurs in the form of a jet outflow of gas, and for the outflow into liquid lead, a gas slug is formed at the bottom of the channel. Satisfactory agreement was obtained between the numerical calculation and the calculation according to the asymptotic model for pressure pulsations in a gas projectile in liquid lead. For water, the results of calculations using the asymptotic model give a significant difference from the results of numerical calculations. In all cases, the velocity of the medium obtained by numerical simulation and when using the asymptotic model differ by an order of magnitude or more.

scholarly journals Subtle Changes or Dramatic Perceptions of Air Pollution in Sydney during COVID-19

Environments ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 2
Author(s):  
Peter Brimblecombe ◽  
Yonghang Lai
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
New South ◽  
Human Mobility ◽  
Ground Level ◽  
Physical Reality ◽  
Social Perceptions ◽  
Search Terms ◽  
South Wales ◽  
Significant Difference

The COVID-19 pandemic made it critical to limit the spread of the disease by enforcing human isolation, restricting travel and reducing social activities. Dramatic improvements to air quality, especially NO2, have often characterised places under COVID-19 restrictions. Air pollution measurements in Sydney in April 2019 and during the lockdown period in April 2020 show reduced daily averaged NO2 concentrations: 8.52 ± 1.92 and 7.85 ± 2.92 ppb, though not significantly so (p1~0.15) and PM2.5 8.91 ± 4.94 and 7.95 ± 2.64 µg m−3, again a non-significant difference (p1~0.18). Satellite imagery suggests changes that parallel those at ground level, but the column densities averaged over space and time, in false-colour, are more dramatic. Changed human mobility could be traced in increasing times spent at home, assessed from Google Mobility Reports and mirrored in decreased traffic flow on a major road, suggesting compliance with the restrictions. Electricity demand for the State of New South Wales was low under lockdown in early April 2020, but it recovered rapidly. Analysis of the uses of search terms: bushfires, air quality, haze and air pollution using Google Trends showed strong links between bushfires and pollution-related terms. The smoke from bushfires in late 2019 may well have added to the general impression of improved air quality during lockdown, despite only modest changes in the ground level measurements. This gives hints that successful regulation of air quality requires maintaining a delicate balance between our social perceptions and the physical reality.

scholarly journals Development of a Line Source Dispersion Model for Gaseous Pollutants by Incorporating Wind Shear near the Ground under Stable Atmospheric Conditions

2020 ◽  
Vol 4 (1) ◽  
pp. 17
Author(s):  
Saisantosh Vamshi Harsha Madiraju ◽  
Ashok Kumar
Keyword(s):  
Air Pollution ◽  
Urban Areas ◽  
Wind Shear ◽  
Dispersion Model ◽  
Near Field ◽  
Ground Level ◽  
Gaseous Pollutants ◽  
Air Pollution Control ◽  
Mobile Sources ◽  
Input Variables

Transportation sources are a major contributor to air pollution in urban areas. The role of air quality modeling is vital in the formulation of air pollution control and management strategies. Many models have appeared in the literature to estimate near-field ground level concentrations from mobile sources moving on a highway. However, current models do not account explicitly for the effect of wind shear (magnitude) near the ground while computing the ground level concentrations near highways from mobile sources. This study presents an analytical model based on the solution of the convective-diffusion equation by incorporating the wind shear near the ground for gaseous pollutants. The model input includes emission rate, wind speed, wind direction, turbulence, and terrain features. The dispersion coefficients are based on the near field parameterization. The sensitivity of the model to compute ground level concentrations for different inputs is presented for three different downwind distances. In general, the model shows Type III sensitivity (i.e., the errors in the input will show a corresponding change in the computed ground level concentrations) for most of the input variables. However, the model equations should be re-examined for three input variables (wind velocity at the reference height and two variables related to the vertical spread of the plume) to make sure that that the model is valid for computing ground level concentrations.

Comparison of soot models for reacting sprays in diesel engine-like conditions

2021 ◽  
pp. 095440702110154
Author(s):  
Pavan Prakash Duvvuri ◽  
Rajesh Kumar Shrivastava ◽  
Sheshadri Sreedhara
Keyword(s):  
Experimental Data ◽  
Volume Fraction ◽  
Soot Volume Fraction ◽  
Modeling Framework ◽  
Aerosol Dynamics ◽  
Significant Difference ◽  
Polycyclic Aromatic ◽  
Order Of Magnitude ◽  
Detailed Kinetics ◽  
Soot Model

Stringent emission legislations and growing health concerns have contributed to the evolution of soot modeling in diesel engines from simple empirical relations to methods involving detailed kinetics and complex aerosol dynamics. In this paper, four different soot models have been evaluated for the high temperature, high pressure combusting dodecane spray cases of engine combustion network (ECN) spray A which mimics engine-relevant conditions. The soot models considered include an empirical, a multistep, a method of moments based, and a discrete sectional method soot model. Two experimental cases with ambient oxygen volume of 21% and 15% have been modeled. A good agreement between simulations and experiments for vapor penetration and heat release rate has been obtained. Quasi-steady soot volume fraction contours for the four soot models have been compared with experiments. Contours of the species and source terms involved in soot modeling have also been compared for a better understanding of soot processes. The empirical soot model results in higher magnitude and spread of soot due to a lack of modeling framework for oxidation through OH species. Among the four models studied, the multistep soot model has been observed to provide the most promising agreement with the experimental data in terms of distribution of soot and location of peak soot volume fraction. Due to a two-way coupling of soot models, the detailed models predict an upstream location for soot as compared to the multi-step soot model which is one way coupled. A significant difference (of an order of magnitude) in the concentration of PAH (polycyclic aromatic hydrocarbons) precursor between multistep and detailed soot models has been observed because of precursor consumption due to the coupling of detailed soot models with chemical kinetics. It is recommended that kinetic schemes, especially those concerning PAH, be validated with experimental data with a kinetics-coupled soot model.

scholarly journals Multi-Year NDVI Values as Indicator of the Relationship between Spatiotemporal Vegetation Dynamics and Environmental Factors in the Qaidam Basin, China

2021 ◽  
Vol 13 (7) ◽  
pp. 1240
Author(s):  
Junpeng Lou ◽  
Guoyin Xu ◽  
Zhongjing Wang ◽  
Zhigang Yang ◽  
Sanchuan Ni
Keyword(s):  
Environmental Factors ◽  
Vegetation Dynamics ◽  
Vegetation Index ◽  
Qaidam Basin ◽  
Elevation Gradient ◽  
Practical Significance ◽  
Elevation Gradients ◽  
Relative Contribution ◽  
Significant Difference ◽  
Different Altitudes

The Qaidam Basin is a unique and complex ecosystem, wherein elevation gradients lead to high spatial heterogeneity in vegetation dynamics and responses to environmental factors. Based on the remote sensing data of Moderate Resolution Imaging Spectroradiometer (MODIS), Tropical Rainfall Measuring Mission (TRMM) and Global Land Data Assimilation System (GLDAS), we analyzed the spatiotemporal variations of vegetation dynamics and responses to precipitation, accumulative temperature (AT) and soil moisture (SM) in the Qaidam Basin from 2001 to 2016. Moreover, the contribution of those factors to vegetation dynamics at different altitudes was analyzed via an artificial neural network (ANN) model. The results indicated that the Normalized Difference Vegetation Index (NDVI) values in the growing season showed an overall upward trend, with an increased rate of 0.001/year. The values of NDVI in low-altitude areas were higher than that in high-altitude areas, and the peak values of NDVI appeared along the elevation gradient at 4400–4600 m. Thanks to the use of ANN, we were able to detect the relative contribution of various environmental factors; the relative contribution rate of AT to the NDVI dynamic was the most significant (35.17%) in the low-elevation region (< 2900 m). In the mid-elevation area (2900–3900 m), precipitation contributed 44.76% of the NDVI dynamics. When the altitude was higher than 3900 m, the relative contribution rates of AT (39.50%) and SM (38.53%) had no significant difference but were significantly higher than that of precipitation (21.97%). The results highlight that the different environmental factors have various contributions to vegetation dynamics at different altitudes, which has important theoretical and practical significance for regulating ecological processes.

scholarly journals Air Pollution, housing and respirfatory tract Infections in Children: NatIonal birth Cohort study (PICNIC): study protocol

BMJ Open ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. e048038
Author(s):  
Graziella Favarato ◽  
Tom Clemens ◽  
Steven Cunningham ◽  
Chris Dibben ◽  
Alison Macfarlane ◽  
...  
Keyword(s):  
Air Pollution ◽  
Cohort Study ◽  
Respiratory Tract Infections ◽  
Ambient Air ◽  
Ambient Air Pollution ◽  
Birth Cohort Study ◽  
Housing Conditions ◽  
Relative Contribution ◽  
Housing Characteristics ◽  
Tract Infections

IntroductionRespiratory tract infections (RTIs) are the most common reason for hospital admission among children <5 years in the UK. The relative contribution of ambient air pollution exposure and adverse housing conditions to RTI admissions in young children is unclear and has not been assessed in a UK context.Methods and analysisThe aim of the PICNIC study (Air Pollution, housing and respiratory tract Infections in Children: NatIonal birth Cohort Study) is to quantify the extent to which in-utero, infant and childhood exposures to ambient air pollution and adverse housing conditions are associated with risk of RTI admissions in children <5 years old. We will use national administrative data birth cohorts, including data from all children born in England in 2005–2014 and in Scotland in 1997–2020, created via linkage between civil registration, maternity and hospital admission data sets. We will further enhance these cohorts via linkage to census data on housing conditions and socioeconomic position and small area-level data on ambient air pollution and building characteristics. We will use time-to-event analyses to examine the association between air pollution, housing characteristics and the risk of RTI admissions in children, calculate population attributable fractions for ambient air pollution and housing characteristics, and use causal mediation analyses to explore the mechanisms through which housing and air pollution influence the risk of infant RTI admission.Ethics, expected impact and disseminationTo date, we have obtained approval from six ethics and information governance committees in England and two in Scotland. Our results will inform parents, national and local governments, the National Health Service and voluntary sector organisations of the relative contribution of adverse housing conditions and air pollution to RTI admissions in young children. We will publish our results in open-access journals and present our results to the public via parent groups and social media and on the PICNIC website. Code and metadata will be published on GitHub.

scholarly journals Industrial pollution related health problems among residents of a rural area in central Kerala

2021 ◽  
Author(s):  
Suchithra Erath Thadathil ◽  
Jaya Koothupalakkal Viswambharan ◽  
Alok Kanjhoor Premdas ◽  
Ashwin Raj
Keyword(s):  
Air Pollution ◽  
Health Effects ◽  
Rural Area ◽  
Odds Ratio ◽  
Skin Lesions ◽  
Control Group ◽  
Case Group ◽  
Cross Sectional ◽  
Adverse Health Effects ◽  
Significant Difference

Background: Air pollution leads to several health effects, the major systems affected were respiratory, dermatology, neurology and ophthalmology. This study is an attempt to find out various health effects of pollution, from a food factory to the nearby residents.Methods: A cross sectional comparative study was performed on 248 residents nearby a food factory, situated in rural area of Thrissur district and a comparative group of 266 participants taken 5km away from this factory.Results: Both the groups were comparable in socio-demographic profile except religion and occupation. There was no statistically significant difference (p>0.05) between the use of firewood in both the groups. The symptoms of major systems involved were respiratory (odds ratio 3.9, 95% CI 2.2 to 6.8), dermatological (odds ratio 18.3, 95% CI 8.3 to 40.7), neurological (odds ratio 13.5, 95% CI 4.1 to 44.7) and ophthalmological (odds ratio 5.9, 95% CI 2.6 to 13.6). The major symptoms complained by them were pruritus (32.7%), skin lesions (17.7%), breathlessness (16.9%), itching eye (13.3%) watering from eye (11.7%) and headache (11.3%). All these symptoms among the case group compared to control group were very high and these associations were highly statistically significant (p<0.001).Conclusions: This study showed an increased occurrence of adverse health effects among the individuals who were residing near the food factory. Therefore this study points out the possibility of environmental pollution (mainly air pollution) as a main factor for the increased prevalence of symptoms among those who reside nearby the factory.

scholarly journals Air pollution: smog and fog in the large cities of Ukraine.

2017 ◽  
Vol 1 (1) ◽  
pp. 1-12
Author(s):  
Rostyslav Sipakov
Keyword(s):  
Mathematical Model ◽  
Air Pollution ◽  
Chemical Kinetics ◽  
Gaseous Pollutants ◽  
Scattering Process ◽  
Large Cities ◽  
Sample Contamination ◽  
Factors Of Influence ◽  
Main Factors ◽  
Harmful Substances

The main factors of air pollution in large cities in Ukraine are described in the article and the main factors of smog have been analyzed on the example of Kyiv in the period January - February 2017. For the analysis of sample contamination points in Kyiv, we used a mathematical model of the spread of solid and gaseous pollutants with the main factors of influence on the scattering process of contaminants in the air: heat, turbulence, chemical kinetics, etc. As a result of the simulation it was confirmed that the smog in Kyiv and surroundings was formed as a result of anticyclone and air pollution by harmful substances, soot and etc.

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