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Air Pollution Studies - Science topic

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Dear Scholars,
Assume a mobile air pollution monitoring strategy using a network of sensors that move around the city, specifically a network of sensors that quantify PM2.5 at a height of 1.5 meters that lasts about 20 minutes. Clearly, using this strategy we would lose temporal resolution to gain spatial resolution.
If we would like to perform spatial interpolation to "fill" the empty spaces, what would you recommend? What do you think about it? What would be your approximations?
Regards
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Hi,
If you expect some local variation and then a non-stationary behavior of your data, probably Empirical Bayesian Kriging will be the one. This is assuming you have a lot of data non left-skewed and you can asumme Gaussian distribution.
In any case, I recommend you to carry out a Cross Validation with a study of RMSE and AMSE, as you can see in Pellicone (2019; 10.1080/17445647.2019.1673840) or in Ferreiro-Lera (2022; 10.1080/17445647.2022.2101949).
I hope I have been helpful.
All the best,
Giovanni.
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Hi all,
Do you have any methodology used to measure population exposure to outdoor PM2.5? I have temporal PM2.5 data and have a set of area wise census population data. In addition, I will have sample based socio-economic and health data too. How do I measure population at risk or their exposure?
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Thanks for the question. The answers also interest me
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If I am getting some negative values in factor loadings while performing principal component analysis (PCA), then I should use that negative values to calculate daily source contribution using multilinear regression (MLR) method or not ?
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The negative sign loading means this parameter has an opposite effect from the other parameters of positive sign. Additionally, when the concentration of the parameters of positive sign rise, the concentration of the other parameter of negative sign will decrease.
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The distribution of daily PM2.5 concentration (hourly) is bimodal in the city of Coyhaique (South of Chile). Coyhaique is the city more polluted by particulate matter accord the WHO. The major source of emission is the burning wood used for cooking and heating, principally at the night. The health risk estimation using longitudinal models could be biassed using the arithmetic mean each 24hrs as an exposure variable. Exist another function for PM2.5 different from the arithmetic mean?.
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For ambient air quality data, log normal distributions are commonly used for some of the reasons you are concerned with. In many cases, in my opinion, the mode may be a more conservative measure risk and exposure analyses. Unfortunately I do not have references to peer reviewed work comparing the errors of one or the parameter used.
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I need help on the correct apparatuses and procedures to trap air in order to analyze the particulate, chemical and biological flora in the air in an area.
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Thank you, Dr Punit Saraswat.
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Much thanks.
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IVL passive samplers may be used for collect of the nitrogen gas for air pollution measurement
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Is there a proven relationship between vehicle emission and cancer diseases?
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Research indicates that nitrogen oxides and sulfur dioxide have an effect on increasing the risk of cancer.
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How should one compare the NOx emissions (where the impact on nature and mankind is mostly local) and green house gase emissions (e.g. CO2) where the Impact is mostly global?
The question is of importance, if for instance a Technology is reducing the CO2 Emission but is increasing the NOx Emission - or vice versa.
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The direct greenhouse gases are carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4). The indirect greenhouse gases are non-methane volatile organic compounds (NMVOCs), nitrogen oxides (NOx) comprised of nitrogen monoxide (NO) and nitrogen dioxide (NO2), sulfur dioxide (SO2), and carbon monoxide (CO).
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I want to correlate meteorological data and particulate matter data. Can I use both the Principal Component Analysis (PCA) and Canonical Correlation Analysis (CCA)? Or is there any preliminary test to determine which one to use? Thanks!
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If you use PCA, you can run any analysis you want on the newly created PCA variables, including correlation with other variables.
If you use CCA, you need an environmental matrix.
Your answer lies in your data structure and what you hope to accomplish.
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Can't separate between the objectives of the two work.
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The ability of a plant to absorb pollutants is dependent on a number of factors (age of the plant, nature of pollutants,, concentration of pollutants in the microspace around the plant, soil and weather conditions) apart from the species' inherent potentials.
Therefore, a design to compare plants tolerance to pollution to pollution absorption may be somewhat difficult.
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How does the altitude affect the PM10 and PM2.5 levels?
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Here a paper of chemical composition and source apportionment of PM10 in a city at 2,650 m:
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Modelling pollutant dispersion in urban centers need street level meteorological data. Whereas much of the research in this field is carriedout using met data from stations far away from study area or with general meteorological details.
Are there any urban air pollutant studies conducted using street level met data by considering the canyon effects of buildings.
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Both US EPA and the US Army (Dugway Proving Ground in Utah) have conducted extensive urban dispersion modelling studies with both real and modelled buildings. 
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Air quality modeling will vary with the geographical locations as the primary pollutants will vary. How could we generalize a model for the same?
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This is a vague question; air quality--and some accompanying meteorological data for selected pollutants in the US--data are available at epa.gov/outdoor-air-quality data.  This site have both "raw" data, formatted data, and data reports.  The raw data should be available on a site-specific basis, but I have not checked.  Generally there is a lag time of a year in putting the information on the web, but otherwise it can be obtained for many years on a site-specific basis. 
There are scores--probably thousands--of statistical and/or chemical/physical models used to estimate ambient air quality, depending upon the pollutant of interest, its "averaging time," its modeling domain, epoch, and receptors of interest.  See the above answers.
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I am attempting to predict future pollutant levels of particulate matter, carbon monoxide, sulfur dioxide, and nitrogen dioxide based upon overall meteorological patterns, traffic count, traffic speed, and location.
The dataset includes pollutant levels at 449 locations, updated around every 5 minutes for 2 months, as well as corresponding traffic data at these locations, and general weather data for the whole area.
Thanks for your time!
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Dear Mr. Sarker,
It is a very interesting problem which can be approached in different ways. In my opinion to predict air quality from overall meteorological patterns, traffic count, traffic speed you should create a weight based equation which combine the previous parameters according to their degree of influence e.g. 50% for traffic count, 25% for meteorological patterns...etc. It would be better if the previous collected parameters are classified then using ordinal numbers each is given a weight and summed. Then according to the measured carbon monoxide, sulfur dioxide, and nitrogen dioxide we can fit a nonlinear equation for each pollutant level. You can also use supervised ANN to find a solution too using the parameters of the meteorological patterns, traffic count...etc and the measured pollutants.
It is better to try to find if there is strong correlation between these parameters and measured pollutants. If there is no correlation for specific parameter then I would remove it to increase confidence and accuracy of the final prediction function.
You can check my publication for predicting physiochemical parameters using measured and calculated parameters. But, in these publications I am using one parameter only.
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Generaly,the fungal concentration has to be higher in PM2.5 than in PM1 because PM2.5 is inclusive of PM1. However, it is totally different with the result obtained in the current qPCR experiment. The PM1' fungal abundance (1.3 _ 105 copies m-3) is higher than that in PM2.5 (9.4 _ 104 copies m-3).  I am curious about the potential explantion.The value is against basic law of physics.
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Interesting ...
I had a read of your ACPD manuscript ( http://www.atmos-chem-phys-discuss.net/acp-2017-204/ ) and I have some comments that hopefully will help answer your question.
First, and as everyone here has said, do make sure that your PM heads are the right ones (i.e., that they were operating within their flow parameters).
Now, I was as intrigued as "Referee 1" about the fact that you report higher concentrations of fungal spores on PM1 than on PM2.5 filters while the PM1 fraction is contained within the PM2.5 fraction.
I have two comments about this issue. The first one on the nature of PM1 and PM2.5 and the second one on the uncertainties of the measurements.
First, PM1 and PM2.5. While it is true that, conceptually, PM1<PM2.5. That is true in practice only when you sample with one inlet. As you and anyone who has captured filter samples "in the wild", two PM1 filters sampled side by side will NEVER measure exactly the same concentration of particles, now if you have a cascade impactor then you can be sure that the what is on the PM1 stage is not on the PM2.5 stage but with parallel samples (as per your setup) you can't be 100% sure of that and you need to assess your uncertainty about the full PM1 and PM2.5 concentrations.
This leads me to the second point about uncertainties. I had a look at Table 1 in your article and I estimated the 95% confidence of the means that you report for "Fungal SSU rRNA gene copy number" for the PM2.5 and PM1 fractions:
  • for PM2.5: 10 +/- 3 * 104 copy/m3
  • for PM1: 14 +/- 7 * 104 copy/m3
Which to me says that those two means are not significantly different.
And now things make some sense in my head because the concentration of fungal spores as a fraction of the PM concentration is less than 0.1% which is a lot less than the variability you'd find between identical instruments sampling the same air. In my experience, 1% agreement between "side-by-side" instruments is an excellent result and you're well within that error margin.
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I read about pollution fungi pollution masks.
Link to the Hong Kong research:
I would like to investigate more about research done and search for new possibilities
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Fungi will not "purify" air (it has no technical meaning), some can reportedly reduce levels if VOC's.  As you say there will be a tradeoff, but it reportedly can be minimal.
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I have observed traffic volume and an air pollutant over a time period of 12hrs during daytime for 3 consecutive days. Is it possible to check seasonality and trends, detrend and fit a Box-Jenkins model for both data?
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Hello, I think yes, because any continuous time series can be discretised and analyzed as a discrete time series. But you must look at the long of your time series because of you need to apply statistical tools among others tools. Also you should keep in ind if the time series is linear or nonlinear. For instance, Pm2.5 and PM10 concentrations are nonlinear and you should work with carefully!
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More dangerous to public health:
1) lower 24 h PM10 mass concentration, lower particle diameter (ultrafine), larger BC mass fraction, more blackish;
OR
2) higher 24h PM10 mass concentration, larger particle diameter, lower BC mass fraction, more brownish;
?
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I think the attached review articles may be helpful for your question.
Good luck
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I want to model the dispersion of different air pollutants (PM10, PM2.5, NOX, SOX) of individual freight vehicles on link level (high used roads). When looking for dispersion functions, I ran always into these kind of formula (http://www.eea.europa.eu/publications/TEC11a/page014.html). If I understand them well, those are not considering; 1. the differences between various pollutants, 2. dispersion generated by the flow of subsequent vehicles, 3. the decrease in concentration throughout time. Is it possible to consider those three too? With which formulas? I thank you in advance.
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There are virtually hundreds of different dispersion models around. If you look at the top of the page, it says: "This annex documents simple models for first estimation or screening." And that's what it is.
For instance, Model C is applicable on roads with complete obstruction by buildings on both sides of the road. Model D does not consider any buildings. A real dispersion situation will be somewhere in between. And the dominant wind direction will not be in a 90° angle to the road and... The selection of a suitable model depends on the situation you want to analyse. And on the level of detail you want to (or have to) achieve.
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I read a statement somewhere that rainfall less than 5 mm per day not only clean the atmosphere, but also increases the air pollution. Is it true? what's the reason? Is it related to formation of particulate matters in the presence of SO2 and Sulfates?
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Amir
A question starts with the reference for the statement
It is not enough to write "I read SOMEWHERE" you have to write where you read that
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I wish to work on different mosses and lichens as biomonitors in air pollution studies. How can I identify them (names, species, the age etc)?
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Bryophyte (moss) genome obviously is the most reliable. But you can identify mosses using a key that details things such as:
Is the gametophyte colony dark green or greyish-white in appearance?
Is the mature spore capsule upright or nodding?
When dry, do the leaves twist around the stem or simply fold inwards to the stem?
Does the leaf have a nerve or not ?
Are the cells in the lower leaf corners markedly different from the other leaf cells?
How large are the spores?
Lichens are not really plants – they are a combination of fungi and algae and are classified based on the fungus and fungal features. In order to identify lichen to species level, lichenologists use common household chemicals and some not-so-common chemicals to test the color reaction of the unique compounds found in the structure of the lichen, as well as using a lichen key to distinguish between species.
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My thesis is about Occurrence, toxicity and source apportionment of PAH in P.M2.5 in Qom metropolitan in IRAN. I need some information about the location of sampling sites. Does anybody have any standard methods related to this subject? For example distance or proximity to the roads, tree, building or ECT.
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Should be Section 58.3 of the NAAQS document from the US-EPA. Some of the appendix info with siting specifications is available here: https://www.law.cornell.edu/cfr/text/40/part-58/appendix-E
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I am interested in using UV light combined with oxidizing reagents to degrade pollutants. Most of the related published papers all mentioned "effective path length". But none of them explained what "effective path length" is and what is it used for. So I wonder if someone with experience of UV light can tell me what exactly this "effective path length" is and how to determine it in real experiment.
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The modelling of light-induced reaction is a very complex task. I agree with Kenneth:" I don't see how there could be any one effective length.."  I believe that "the effective path length" is an oversimpliification to describe a real system. The refs you provided are not from the top journals. "The effective path length" is not well defined and is not generally used in the literature. 
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Former PM10 was defined to be larger than 2.5µm and smaller than 10µm, now all smaller than 10µm?
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The 10 micrometer is not the actual size, but an eqivalent aerodynamic size. A PM10 particle may have a physical dimension exceeding 10 micrometers. Definition: The aerodynamic diameter of an irregular particle is defined as the diameter of the spherical particle with a density of 1000 kg/m3 and the same settling velocity as the irregular particle.
According to the current definition, PM2.5 particles are a part of PM10.
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For e.g. TiO2 is added in order to reduce the NOx level. I would like to know that to know the amount of NOx ,COx produced by the road s
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Try calculating Emission Factors in the category Fugitive Dust from paved or unpaved road. Check more info. From USA EPA at https://www3.epa.gov/ttnchie1/ap42/ch13/related/c13s02.html
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Just a rough estimate. My idea was. First calculating Mass flow rate = air flow rate through the column / the molar volume of air at normal temperature * Pollutant concentration ppm * Molecular weight pollutant. Result will be g/H2S/min
Than I wanted to calculate Carbon bed lifetime = Media capacity for H2S * Media volume/ Mass flow rate. This shoud give me idea about capacity of my column exactly for H2S g. 
Than just calculation of time. But I don´t know how, results are nonsense. :(
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Dear Michal
The Dr  Sébastien Vaesen's answer is completely perfect 
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How can I calculate the enrichment factor of air particulate and metals?
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Enrichment Factor (EF) of any element X in aerosols can be calculated using the following formula:
EF of X = (X/Al)samples / (X/Al) in ucc
here, ucc stands for upper continental crust. For more details, you can read the attached paper.
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Total sulfate is originated from sea salt, dust, and produced by oxidation of SO2 in the atmosphere.
I would like to know how to calculate the portions of sea-salt sulfate and mineral dust sulfate by using sodium and calcium or magnesium, respectively, as tracers.
in another way, how can I estimate the portion of  non-sea salt sulfate?
thanks
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I have SO2 and NO2 values for stack in ppm. i want to convert it in mg/m3 and mg/Nm3.
if I am taking reading direct in mg/m3 from flue gas analyser (Testo 350) and then calculating manually ppm to mg/m3 but both are not coming same.
Kindly suggest me.
Thanks in advance
Regards
Anand Dev 
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Dear Anand Dev Gupta,
Br
Marek Maasikmets
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I am working on monitoring the air quality monitoring and we would like to inquire what are the potential information that we can infer from those parameters?
Is there any recommended way to extract them.
Thank you in advance.
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It does depend which issues of concern you have 
WHO gives 10 aims of AQ monitoring including evaluation of correspondence to limit values, estimation of sources of pollution, evaluation of accuracy of modelling, evaluation of risks to human health of plants, estimate the trends, model the future trends etc
So, 1st determine which issues are important in your area-city. Then you can choose does analyses of your data help to solve/answer issues concerned.
Thus, the answer depends on situation in your site-area.
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Dear colleagues,
Does anyone have the references for emission factor (in g/km) for on-road mobile sources in developed countries (US, EU)?
Thank you for your supports.
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Kindly provide information on the technologies available world wide as well as in India for crematoria emission control. Information on this study any patents.
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It might be worthwhile to have a look at
http://charmeck.org/mecklenburg/county/LUESA/AirQuality/ PermittingRegulations/Pages/emissioncalcspsheet.aspx
It is pretty nice speadsheets where one of them i actually specially designed for emissions from crematoria.
good luck
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Falling film absorber is used to remove pollutant from gaseous emission by absorption and diffusion through a liquid media. Liquid media can be water or any other liquid, which has ability of absorb the air pollutant.
How do we calculate the length a falling film absorber column to remove a particular air pollutant up to a desired efficiency.
Thanks,
Rishu
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For free on the web
Chemical Reaction Engineering
Third Edition
Octave Levenspiel
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I need the measure to build six Bergerhoff Model's structures like length, width and height of each part of it and parameters to use it to measure the atmospheric dustfall.
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Hans Puxbaum is right, the relation with health hazards is weak, at least effects by inhalation. Although some indirect effects can be expected, for instance by uptake of deposited metals in vegetables, or by ingestion of polluted soil by children. But than again, this effect is uncertain.
If you can read German (perhaps with a bit of help of Google translate?), some more information is available at the sites of LANUV, the State Agency for Nature, Environment and Consumer Protection of North Rhine-Westphalia in Germany. Here are some links (Staubniederschlag is dust depostion):
http://www.lanuv.nrw.de/umwelt/luft/immissionen/staubniederschlag/ with background information, a short description of the Bergerhoff method, German norms for 5 metals and buttons to Messnetz( measurement network):
with indications of possible applications of the method like Hans Puxbaum meant,
and Messergebnisse (Measurement results):
with annual and trend publications on dust deposition and its components like Pb, Cd, As, Ni, Tl, Hg, and dioxins, furanes and PCB's.
Hope this helps!
Greetings,
Marcel Severijnen
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Hi,
I was looking for some key articles for example well cited ones on the primary determinants of outside or ambient air pollution of cities worldwide. Are you aware of any such articles?
Any help will be much appreciated.
Thank you.
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Provided that I have the data of concentration of PM10 monthly and population estimates based on census data for each grids in my study area.
I used BenMAP model to interpolate the data (using Voronoi Neighborhood Averaging method) and already obtained the mean concentration level of PM10 for each grids (the population in the respective grids should be the population that is exposed right?). How about the non-exposed population?
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One option is to collect data in rural areas and compare .///chockalingam.civil@bharathuniv.ac.in
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  1. I am working on "vehicular exhaust dispersion studies", for my research study I need to simulate vehicular movement system in wind-tunnel.
  2. what are the similarity criteria to be followed for the above case and in wind tunnel studies.
So please give me some inputs regarding the above cases
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There has been a study made for the Boston Central Artery Project in the 1990s. They used a conveyer belt with half-globes to simulate vehicle movement in the wind tunnel. Number of globes and speed of the conveyer were varied in order to model different traffic situations. I don't have access to the report, but maybe you'll find something about the Boston project.
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Could anyone confirm the fact that the increase of CO has an effect in temperature in the site of it's emmision
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Carbon monoxide is not known as a direct contributor to climate change, however, it does play a role in this area, since its presence affects concentrations of other greenhouse gases including methane, tropospheric ozone and carbon dioxide (http://esseacourses.strategies.org/module.php?module_id=170).
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SIA (secondary inorganic aerosols) like SO4, NO3, NH4 etc. have been found to contribute significantly to PM2.5 mass in urban areas. Is there a general rule that they are predominantly a result of secondary formation from their gaseous precursors (SO2, NO2, NH3 etc)? Or are they also primarily emitted? Can we make some generalizations based on current state of knowledge?
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With respect to your comments particularly about sulfate, another important source is sea salt, in which the concentration of this ion is usually around 10%, according to the SPECIATE database (Profile Number: 4310110). It is also well known that this ion is already present in seawater, due to the oxidation of Dimethyl Sulfide (DMS) emitted by phytoplankton, so it is definitely emitted as a primary aerosol, in this case.
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I am looking about the air pollutants doseage.There are two questions need to sort it out.
1. Could you please tell me how I can get the proportion by weight of particles that are inhalable by the test species (PM2.5, PM10, NO, CO)
2. the inhalable fraction (inclusion of this parameter is not essential provided that the aerosol has reasonable respirability for the intended species. PM2.5, PM10, NO, CO are they essential or not?
Thanks for your help!
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Okay. There are a number of ways to do in vivo PM studies. I realize that there are few studies of very small (i.e. "ultrafines"), but new techniques are being developed. Check out Buckley, et al. (2016): http://www.tandfonline.com/doi/abs/10.1080/02786826.2015.1124987. There have been numerous pharmacological studies (e.g. drug delivery to the lung) that can help. For example, you might be able to apply alveolar deposition models (see: Khajeh-Hosseini-Dalasm and Longest (2016): http://www.sciencedirect.com/science/article/pii/S0021850214001487.
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the impact of commercial kitchens in the surrounding environment, by vapors , odor . or smoke and if there are nay  methods of reducing such pollution  
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I am having Latitude, Longitude and pollution concentration data for 50 points. I want to plot the contour map on the google earth, how do I do that?
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Dear Researcher
please check this if it is helpful for you.
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I am doing analysis of PM10 collected on Quartz fiber filter.I am expecting organic compounds like n-alkanoic acids decanoic acid, dodecanoic acid etc...I have only one standard that is Heptadecanoic acid.Could i use this chemical for quantify all the acids by making calibration curve from this standard.
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Hi Sarika,
I dont think so. I analysed monocarboxylic acids (C8 - C20) by GC-MS 5 years ago. I derivatized them into methyl esters by BF3/methanol and the peak area was different for different acids. The peak area of C16 was the biggest. However I dont have experiences with HPLC.
Rastislav.... PM10 means particles less than 10 micrometers. PM is Particulate Matter.
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I want to know the air pollutant levels for last three years (2013, 2014 and 2015) for my current study. However the data are still not available at the website. How could I estimate the levels for that particular years by using previous years trend (2012, 2011 and 2010). 
Or is there any other methods that I could use?
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Hi Qiang Chen, would you please explain more about grey model
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Please provide me both methods in urgent.
Thanking you
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You can do benzene and CH4 and many other species by GC-FID if you use whole air sampling in canisters along with pre-concentration as described here:
Colman, J. J., A. L. Swanson, S. Meinardi, B. C. Sive, D. R. Blake, and F. S. Rowland, Description of the analysis of a wide range of volatile organic compounds in whole air samples collected during PEM-Tropics A and B, Anal. Chem., 73, 3723– 3731, 2001.
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An 8th grade student wants to see how the conc. of CO2 changes the conductivity of air, ala air pollution (CO2) from combustion. Could one just use a TCD- with N2 as carrier gas-add CO2 (the sample) and measure the signal as a function of CO2 (%)?   Air is 78% N2--so N2 is close to air, and air (O2)  would burn the TCD resistors.  This is a neat Wheatstone  Bridge--and maybe one can get a relationship to ohms, and then CHANGE TEMPERATURE OF THE CELL---and compare to literature. May be a bit narrow T range.
What do you think?
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One could do that. There is sufficient difference in thermal conductivity between nitrogen and carbon dioxide to get a usable signal. However if the student is looking at normal carbon dioxide concentrations in ambient air (~400 ppm or so), the change in conductivity will be minimal. The thermal conductivity values could also be calculated based on the concentrations and standard values. The only case where the change would be substantial would be in the case of flue gas or combustion exhaust.
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i am using Respirable Dust Sampler for ambient air quality monitoring. I want to keep maintain my quality records like uncertainty, %RSD. Kindly send me detail about this, excel calculation sheet.
i welcome some valuable suggestions/query regarding this.
Thanks in advance. 
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The attached US EPA publication "Quality Assurance Guidance Document 2.12: Monitoring PM2.5 in Ambient Air Using Designated Reference or Class I Equivalent Methods" may provide you with useful information about measuring fine particulates in ambient air.
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Please point me in the direction of some literature or calculation sheet regarding the same.
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Dear Anand,
Please read the following text:
Emission Examples: Stack Gas Concentrations
Example 1 - Converting CAC Releases from ppm (volume) to tonnes
If you have had your stack tested for NOx (expressed as NO2), Carbon Monoxide (CO), or Sulphur Dioxide (SO2) you will notice that the results from the laboratory are usually in the units of parts per million volume or ppm (volume). Before you can use these number to estimate your releases of these substances for the NPRI you need to Convert from ppm (volume) to a mass release in tonnes.
This example will walk you through the process of converting from ppm (volume) to an annual mass release in tonnes for NOx. This same method can be used for CO and SO2.
1. The first step is to calculate the stack's volumetric gas flow rate ( ) using the formula below:
(m3/min) = (gas velocity, m/s) * [π * (internal stack diameter, m)2 /4] * 60 s/min
where π = 3.1416
2. Then you need to correct the stack gas flow rate for the moisture content and standard conditions using the formula below:
Example: If the stack gas volumetric flow is 1330 m3/min at 80°C and 1 atm pressure with a moisture content of 10%, the dry volumetric stack flow rate is:
= 925.84 m3/min
3. The next step is to Convert from ppm (volume) to mass emission rate (kg/h) as follows:
Example: NOx is emitted from a stack that is 2.1 ppm by volume. The dry volumetric stack flow rate is 925.84 m3/min. Density of air at standard conditions is 1.29 kg/m3
= 0.239 kg/h
4. Use the mass emission rate to calculate the yearly NOx release.
= 2093.64 kg
= 2.09 tonnes NOx released for the year
Molecular Weights (MW) for Air and CAC Substances
CAC Substance
Molecular Weight (grams/mole)
Air
28.97
NOx (expressed as NO2)
46.00
Carbon Monoxide (CO)
28.00
Sulphur Dioxide (SO2)
64.06
 
Example 2 - Converting CAC Releases from ppm (mass) to tonnes
If you have had your stack tested for total particulate matter (TPM), PM10 or PM2.5 you will notice that the results from the laboratory are usually in the units of parts per million mass or ppm (mass). Before you can use these number to estimate your releases of these substances for the NPRI you need to convert from ppm (mass) to a mass release in tonnes.
This example will walk you through the process of converting from ppm (mass) to an annual mass release in tonnes for TPM. This same method can be used for PM10 and PM2.5 as well.
The first step is to convert from ppm (mass) to the mass emission rate as follows:Convert ppm to grams / tonne
Use the stack mass flow rate (kg/min) to Convert to mass emission rate.
Example: The TPM emission rate from the stack is 250 ppm (mass). The dry mass flow rate is 10.54 kg/min. The stack is operational 24 hours a day, 365 days a year.
(i.e.525 600 minute per year).
a) Convert from ppm to g/tonne by using the conversion of:
b) Using stack dry mass flow rate, calculate the mass emission rate:
2. Then use the mass emission rate to calculate the yearly TPM release.
The TPM release for this particular stack is 1.384 tonnes.
Example 3 - Converting CAC Releases from mass per volume to tonnes
If you have had your stack tested for volatile organic compounds (VOCs) you will notice that the results from the laboratory are usually in the units of mass per volume. Typically the result of the VOC stack testing is expressed in the units of m g/m3. Before you can use these numbers to estimate the release of these substances for the NPRI you need to Convert from the mass per volume values to an annual mass release in tonnes.
This example will walk you through the process of converting from a mass per volume value to an annual mass release in tonnes for VOCs.
1. The first step is to calculate the stack's volumetric gas flow rate (V) using the formula below:
V(m3/min) = (gas velocity, m/s) * [π * (internal stack diameter, m)2 /4] * 60 s/min
where π = 3.1416
2. Then you need to correct the stack gas flow rate for the moisture content and standard conditions using the formula below:
Example: If the stack gas volumetric flow is 1330 m3/min at 80°C and 1 atm pressure with a moisture content of 10%, the dry volumetric stack flow rate is:
= 925.84 m3/min
3. The next step is to use the stack flow rate (m3/min) to Convert to a mass emission rate as follows:
Example: VOCs are emitted from a stack that at a rate of 60 m g/m3. The dry volumetric stack flow rate is 925.84 m3/min.
Mass Emission Rate = 925.84 m3/min * 60 m g /m3 * 60 minute / hour
= 3 333 024 m g/hour
4. Use the mass emission rate to calculate the yearly VOCs release.
= 0.029 tonnes VOC
ASIDE:
The following two examples use the duration of the stack test to calculate an emission factor for the process. To simplify the calculation a test duration of one hour was used. If the duration of your stack testing was different you will first need to Convert it to a one hour basis before following the methods outlined in Examples 4 and 5.
Example: Stack duration is 2 hours and a TPM release value of 316.2 g during the test period.
Example: Stack testing was based on a total volume sampled instead of time. A total of 107 000 m3 of emissions needed to be tested. The dry volumetric stack flow rate was 1197 m3 per minute. The total release of VOCs during the testing period was 6.42g.
Example 4 - Calculating CAC Releases from Source Testing and Fuel Consumption Data
Many facilities participating in a stack testing program will have information on the fuel feed rate during the test period and total annual fuel consumption. This data can be used to more accurately estimate CAC releases taking into account the process variations and production rates. For example, you may choose to use this method if the equipment is only operation for part of the year or the fuel feed rate fluctuates based on the facility's production rate.
To illustrate this method the data in Example 2 was assigned to a boiler burning bituminous coal.
From Example 2:
1. The first step is to convert from ppm (mass) to the mass emission rate as follows:
Convert ppm to grams / tonne
Use the stack mass flow rate (kg/min) to Convert to mass emission rate.
Example: The TPM emission rate from the stack is 250 ppm (mass). The dry mass flow rate is 10.54 kg/min. The stack is operational 24 hours a day, 365 days a year.
(i.e.525 600 minute per year).
a) Convert from ppm to g/tonne by using the conversion of:
b) Using stack dry mass flow rate, calculate the mass emission rate:
converting to grams per hour:
2. Use the mass emission rate and the boiler fuel feed rate to Create CAC production rate to fuel consumption to Create an emission factor.
a) Use the general formula below to Create the emission factor:
Example: The TPM emissions being released from the stack are the result of combustion in a bituminous coal fired boiler. The stack testing results were based on a one hour test period. The fuel feed rate of the boiler during the test was 25 kg bituminous coal per hour.
3. Use the emission factor calculated above along with the boiler's specific total annual consumption of bituminous coal.
Example: The boiler in question burned 218.85 tonnes of bituminous coal in the reporting year. The calculated emission factor for TPM for this boiler was 6.324 kg per tonne bituminous coal burned.
= 1384 kg TPM released
= 1.384 tonnes TPM released
The TPM release for this particular stack is 1.384 tonnes.
Example 5 - Calculating CAC Releases from Source Testing and Total Production Data
Another method that can be used to estimate your CAC releases is to correlate your stack testing data with the facility's production data. Most facilities participating in a stack testing program will have information on the production rate during the test period and total annual production. This data can be used to more accurately estimate CAC releases taking into account the process variations and production rates. For example, you may choose to use this method if the process line is only operation for part of the year or the production rate fluctuates with demand for the product.
To illustrate this method the data in Example 3 was assigned to the fluidized bed prilling process used in urea production.
From Example 3:
1. The first step is to calculate the stack's volumetric gas flow rate (V) using the formula below:
V(m3/min) = (gas velocity, m/s) * [π * (internal stack diameter, m)2 /4] * 60 s/min
where π = 3.1416
2. Then you need to correct the stack gas flow rate for the moisture content and standard conditions using the formula below:
Example: If the stack gas volumetric flow is 1330 m3/min at 80°C and 1 atm pressure with a moisture content of 10%, the dry volumetric stack flow rate is:
= 925.84 m3/min
3. The next step is to use the stack flow rate (m3/min) to Convert to a mass emission rate as follows:
Example: VOCs are emitted from a stack that at a rate of 60 m g/m3. The dry volumetric stack flow rate is 925.84 m3/min.
Mass Emission Rate = 925.84 m3/min * 60 m g /m3 * 60 minute / hour
= 3 333 024 m g/hour
= 3.33 g/hour
Use the mass emission rate and the facility's production rate to Create CAC release to total production emission factor.
a) Use the general formula below to Create the emission factor:
NOTE: The facility's production rate can be in tonnes product produced, number of unit produced or any other applicable measure of production. Likewise, the CAC substance release could be in any units of mass. This example will use tonnes product produced and grams of substance released to illustrate the process.
Example: The VOC emissions being released from the stack are the result of the fluidized bed prilling processes used in urea production. The stack testing results were based on a one hour test period. The production rate of the facility during the test was 23 tonnes of urea per hour.
3. Use the emission factor calculated above along with the facility's total annual production of urea.
Example: The facility in question produces a total of 203 210 tonnes of urea in the reporting year. The emission factor calculated in, part 2 above, for VOCs from the fluidized bed prilling process, was 0.145g per tonne urea produced.
= 29 465.45g VOC released
= 0.029 tonnes VOC released
The VOC release for this particular stack is 0.029 tonnes.
 For better view, please use the following link:
For other references, please use the following links:
Hoping this will be helpful,
Rafik
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Air quality in major cities across the globe is taking a hit to alarming levels due to large scale industrialization without respecting emission norms. Considering this for healthy life (safe and clean air) what can be the best possible and technologically viable alternative for large scale purification of contaminated air? There are reasonably good research activities....but some collective and major initiatives are needed for a better future...suggestions!!!
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Reduce emission of noxious gases in the environment and increase tree cover. 
University of Engineering and Technology (UTEC), Peru  has developed air-purifying billboard and installed near a construction zone in Lima, a city that's famous for having the worst air quality in all of South America. The billboard works by combining polluted air with water, using basic thermodynamic principles to actively dissolve the pollutants (such as bacteria, dust and germs) in water to release fresh air. It is claimed that the billboard filtered around 500,000 cubic meters of air within one week. Pl refer following threads for various devices claiming to purify air in various ways;-
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Who knows what can be the source of the newly detected by satellites high SO2 fluxes as shown in the attached file, distributed by SACS (BIRA)?.
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Surprisingly enough, this SO2 plume has originated from the Etna Volcano, in Italy. The eruption on December 3rd was quite large and the SO2 plume rose as high as 7 or 8km while being constantly transported eastwards. There is no associated ash plume. Below you find an answer from Nicolas Theys, BIRA, Belgium.
------------------
This SO2 plume is coming from Etna eruption on 3rd December : http://sacs.aeronomie.be/nrt/IasiOfl/2015/12.orb_V3/03/iasiB_dbt20151203dc_207_lr.gif
You can follow the transport of the plume on SACS day by day until it reaches China.
The eruption was one the most vigorous eruption of Etna since the last 2 decades and the SO2 plume was emitted quite high (7-8 km) in the atmosphere where it was then transported Eastward as it is often the case for Etna plumes.
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When a nuclear pollution happen, it means that we have air pollution whose form can be considered as nuclear aerosols. Therefore, I want to calculate and work on this topic but I need some optical properties about the particles that consist such nuclear aerosols.
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Aerosols play an important role in the global climate, the radiative forcing of climate, and the Earth’s radiative balance.  They act by modifying the local and planetary albed and by absorbing the upward terrestrial thermal radiation. Aerosols influence the radiation balance through two key processes: directly, by scattering and absorbing solar radiation, and indirectly, by acting as cloud condensation nuclei and thus dramatically affecting the optical properties of clouds.
see attached file as well to more detail about it.
Regards
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Air and land pollution pose a great threat to life on earth. 150 nations were attracted to meet in Paris these days to discuss this problem and to look for mitigation measures to reduce these serious pollutants.
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I think we also should consider respirable particulates. The smallest fractions (PM2.5, PM1 and soot). They have very bad influence to human health, and controlling is very hard (e.g. resuspension from traffic).
Moreover, particulates are carriers for another pollutants, heavy metals ia.
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we connected a compressed air line in spite of blowers to the aeration tank.
i feel that, compressed air is mot giving satisfactory results compared to the blowers, but i am not able to find any literature on the same topic. is the use of blower or industrial compressed air system appropriate for aeration system, and how can it be adjusted? can compressed air in fact replace blower systems in the short and the long term? 
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Good morning
Thank you Silas Derenzo sir. 
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In a smelting copper plant we have offgases including particulate matter and SO2 that exceed the allowable value.as you know in such plant we have high value of SO2 and the offgases are so hot about 1300 degree centigrade.
despite of using ESP in the plant,the values of SO2 are high yet.how and what controling method should use to eliminate the values to the allowable one?
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sorry, I think the document with copper smelting is:
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Total Suspended Particulate matter (TSPM) includes Suspended Particulate Matter or SPM (Aerodynamic diameter of 100 micrometer or less) and Respirable suspended Particulate Matter or RSPM (Aerodynamic diameter of 10 micrometer or less). So is it possible to have a sample in which SPM<RSPM? It may be noted that TSPM is always greater than RSPM and SPM.
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Remember you are talking about units of concentration. Hence, you are dealing with mass of PM per unit volume of ambient air. So, lets say that a substantial portion of your TSPM is made up of particles of sizes 10 microns and smaller. Then, you will expect that there will actually be a large concentration of particulate mater of size 10 microns and less when you look individually at this one fraction of PM in the ambient air. So yes, it is possible.
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I am working in the production of the above agricultural products but read some item that potash has a negative effects on beneficial bacteria in the soil. I would like to know if it has the same effects on this bacteria too.
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Yes
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I collected biological slid containing fungi spore. To scan these slid I require two days for one slide. Is there any software which can scan digital photo of biological slid and it will count spores in the slide within minute
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Hi, do you have downstream applications - or do you just need the counts? In case yiu do not need the slids afterwards: I would stain the spores to enhance the contrast (Lacto-glycerine cotton blue), take microscopic photos or a simple scan (depending on objects size) and than try Fiji (ImageJ), using thresholding and automatic counting (depending on quantity). It is useless, if the spores lie too close to each other and do not seperate in the picture. In some cases you need expensive software or a lot of patience -
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I am trying to measure how much oxygen a plant (urban trees) produces and I need a methodology to do it. Then I want to compare if the quantity of oxygen produced by the plants in a urban area is enough for the people that live in the urban area. Considering that this place has few trees and many cars. I am assuming the air quality is low due to pollution from cars. 
I hope someone can help with some methodology, instruments or other similar works that have been done.
Thanks
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Dear Jaime,
An adult man needs about 700 grams of oxygen per day (255 kg/year), corresponding to what provide a dozen trees in one year (from 15 to 30 kg per tree). Urban tree therefore produces a very small share of the large amounts of oxygen consumed in large cities, but the native oxygen produced by the leaves could play an important health role for the trees themselves, and their proximity, notably in the canopy.
With my best regards
Prof. Bachir ACHOUR
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After I have applied both AAE and EAE there appears to be a sort of slight overlap between aerosol of biomass burning and industrial origin. On which other bases can a very clear distinction be created between this aerosol sources. 
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Use the BC measurement at 880 nm to determine Black Carbon (BC) mass, the light absorbing organics usually do not absorb significantly there. Regression plots between BC from biomass burning and levoglucosan should provide the information on the robustness of your two-component Aethalometer model (biomass, fossil fuel). The intersect (BC at zero levoglucosan concentration) is an indicator of the levoglucosan stability and the accuracy of the  fossil AAE.
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I had collected biological slide containing spores from poultry farm.
Please see attachment.
how to scan this slid online free is there any software. How to use this softwere
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Hi Sabash,
i have no experience in this field .
best wishes,
Mark
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E-cigarettes have become increasingly popular and many believe they are a healthier alternative to traditional cigarettes. But do the substances in e-cigarette vapor really just get exhaled with the vapor? The answer should lie in their particle size which determines deposition in the human respiratory system and organs. Any measurements of particle size distributions published in peer-reviewed papers would be of great interest.
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I am not sure it there is any publication yet that reliably tells the particle size distribution of e-cigarettes and I doubt that there is any publication that based on the particle size distribution gives a reasonable health risk analyse:
1) e-cigarette vapor is completely volatile (by measuring the psd high dilution is required in order to prevent coagulation artefacts)
2) deposition in the human respiratory tract is based on particle size; however, e-cigarettes have a high potential of higroscopic growth but may also completely evaporate depending on their concentration. Equilibrium (in terms of phase transition) models can not be applied here, but most lung deposition models that consider phase transition are equilibrium models
I conclude: tricky topic
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I have one year long time series of CO2, CO and CH4 over an urban city. I want to remove their background for seeing the actual variability from their local emissions. What is the procedure for calculating the background mixing ratios of these gases on daily and monthly basis?
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Dear Naveen,
Please go through the attached research article, may be helpful to you.
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What are the sources of public information (information, which can be downloaded and processed by the program in R) on air quality and on values of meteorological factors over Earth territory, over Europe territory, including over Ukraine territory? Interesting data in dynamics, data on both the atmosphere and the emissions, etc. For example (but the link does not belong to Ukraine, unfortunately): http://www.eea.europa.eu/data-and-maps
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Dear Vitalii,
A very good source of public information on atmospheric emissions is the EMEP CEIP webpage (which includes Ukraine territory)
For meteorological data you can check the following webpage, which allows downloading the METAR data from the different meteorological networks all over the world
Regarding air quality data, I am only aware of the EEA air quality database, which you already posted in your comment. 
Hope the answer is hepful
Marc
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Hi,
I'm using a lagrangian dispersion model to study the contribuition of urban traffic to concentrations of NOX. We need to compare model results with measurements, but of course the model does not include chemistry and cannot simulate the photochemical NOX.On the other hand we both have a regional scale model that can treat the full chemistry and we have access to several monitoring station data.
I'm currently studying the method described in  Saravanan A., et al, "A Method for Estimating Urban Background Concentrations in Support of Hybrid Air Pollution Modeling for Environmental Health Studies", Int. J. Environ. Res. Public Health 2014. but I can't seem to find a practical example of the method application.
Can someone suggest an alternative method with a reference in which we can see it actually applied to some cases?
thanks
Felicita
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Yes Francesco,
I received it. Thank you very much!
Felicita
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I wonder, can i use Gauss Model to predict where and how high the concentration of TSP's emission from concrete batching plant in rural area near plant?
Because in those areas, wind direction is different in every hour but there is a dominant one. Wind velocity almost stable but in a range of 0 - 4 m/s. Is it too low?
Or is there any other model to predict concentration of air pollutant in rural area? Can you give me any recommendation models to predict concentration of air pollutant (especially for Total suspended particulate) in rural area?
Your answer is a great help, thanks a lot researcher
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Khotimah, 
Sure, what is the domain size, and where is the target area, you are looking for?
I think the easy to do this is using NOAA online dispersion model,
I suggest you to start from meteorological data of GDAS. However, if you are looking TSPs, deposition rate will vary with particle sizes. It will just give you a rough number of spatial variation of TSP near a certain source.
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Few studies consider the increased ventilation rate associated with active travel modes. Ventilation rates are important because it affects the amount of inhaled pollutants. There is some research for cyclists but Dirk’s et al (2012) study suggests we lack research on pedestrians:
Does someone has recent research that does provide insight into pedestrian’s ventilation rate?
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the only study I could find that measured Ventilation during walking (study with only 1 subject!) gives the following values: walking at 3 mph: 1.3 m3/h and walking at 5 mph: 1.6 m3/h.
Seems that only a very small number of studies measured ventilation in a direct way while walking, but that the results are comparable.
Bas de Geus
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UV rays are known since ages. How is the pollution today affecting skin sensitivity to sunlight?
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The cause of PLE is not yet understood. It is thought to be due to a type IV delayed-type hypersensitivity to an allergen produced in the body following sunlight exposure. It can be provoked by UVA or UVB rays. Some progression to autoimmune disease has been observed. Pathogenic strains of H. pylori have been shown to
activate the epidermal growth factor receptor (EGFR), a membrane protein with a tyrosine kinase domain. Activation of the EGFR by H. pylori is associated with altered
signal transduction and gene expression in host epithelial cells that may contribute to pathogenesis.
Bashir A. H. H.1,2*, Yousif S. M.2 and Mahmoud M. O. A.2. Clinicoepidemiological study in Sudanese patients: Prevalence and effect of eradicative triple therapy on
extra digestive Helicobacter pylori skin manifestations, EdHpSm. Clinical Reviews and Opinions Vol. 3(2), pp. 14-19, February 2011.
ISSN 2141-2553 ©2011 Academic Journals
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I have seen most of papers comparing modis aod with sun photometers aod at ground, instead of that is there any other alternative available to compare Modis L3 AOD with PM10, 2.5 mass at ground level. 
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Hi,
I came across a few articles, searching for sources of a small but interesting PM event in Flanders, Belgium in July last year: "Detecting source of unexpected peak of PM10 over Flanders (Belgium): a walk through public available information". See my article on researchgate and look for references 20, 21, 22, 23, 24 and 25. You may find different correlations of course, depending on differences in the aerosols, and within the uncertainties of the methods. http://tinyurl.com/pnxlyks
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Emission of air pollutants from any means will be a threat to living things. Please suggest some statistical data on how the humans are being affected by pollutants over the decades. Any sort of information will be helpful. Thanks. 
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Thank you for your answers. 
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Imagine we have collected air quality data from four sites, consisting of 100 samples from each site- one variable contains the site identifier, the second contains the NOx levels and the third contains the PM10 concentrations. the fourth variable contains data regarding the seasonality (summer, autumn, winter, spring)
question 2) what numeric or graphical methods can we use to determine if our data are normally distributed?
question 3) should the data prove to be normallydistributed, and we wanted to discover if there were any statistical differences between the two sites what would be the most appropraite test to use?
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If you check Figure 2 in our paper, Fine particle air pollution and secondhand smoke exposures and risks inside 66 US casinos James L. Repace a,b,n, Ruo-Ting Jiang c, Viviana Acevedo-Bolton c, Kai-Chung Cheng c, Neil E. Klepeis c, Wayne R. Ott c, Lynn M. Hildemann, which is available on Research Gate, you'll find a comparison of indoor and outdoor PM2.5 for 66 casinos, plotted on a log-normal plot.  As you can see, both distributions fit the log-normal distribution very well.  
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Emission inventories are always associated with uncertainty? I need a software to carry out uncertainty analysis on sets of emission values. @RISK or CrystalBall or any other one will be highly appreciated.
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Giwa, there is a Software called Emisens, it estimates uncertainties from road traffic emissions, please check this PhD thesis: http://infoscience.epfl.ch/record/149809/files/EPFL_TH4793.pdf. You can also contact Professor Alain Clappier, he developed this Software: alain.clappier@live-cnrs.unistra.fr
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I have ionic data for aerosol, trace gases and surface snow. The chemical species under study include : NO2, NO3-, SO2, SO42-, Cl. I would like to study the inter-conversion of these precursor species within the air snow boundary layer. How the meterological parameters effect their conversion reactions. Can anyone suggest a simple box model for this study?
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@Rosaline
After your last entry I understand much better what you are after. However, the area of heterogeneous conversion of NOx is a very tricky one. My main experience is the interaction with walls of smog chambers. It appears that the presence of a surface water layer is essential. However, I think that up till today there is not a good kinetic description for the interconversions taking place in such a rather well-defined environment. A amin issue is the formation of nitrous acid. This is a key compound for starting the photochemical cycle. Of course this is of more importance at sites where photochemistry occurs
 There is also the interaction of nitric (and sulfuric) acid with seasalt, but this reaction is fast and occurs already in the aerosol in the air.
By the way did you have a look at the literature on the heterogeneous / surface reactions of the compounds?
ISORROPIA only provides equilibria but the question for you obviously is how fast?
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I'm doing some research on this.
I will appreciate your help.
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The Government of Alberta site listed at the top of the first responses is a good one. I have worked with researchers in this group on poultry barn environments. We looked at respiratory disease incidence as it related to the dust composition of the barn, and litter treatments to control barn dust. I did a lot of the early microscopy work to characterize the dust in various barn environments.  I was working with John Feddes, who joined this group after he retired from the University of Alberta. I recommend looking up some of his work to get you started. They have also looked at worker health and dust from farm-types other than poultry. 
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APTI = {[A(T+P)]+R}/10 , where A-ascorbic acid mg/g T- total chlorophyll mg/g, P-pH of the leaf extract and R - relative water content in pecentage.
as the units are different from each other biochemical parameter as it can be identified from the formulae, so would like to know what is the assumptions or justification has been made. 
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Singh and Rao dvelopped this index in the late 80s. The units are mixed and do not have physical meaning, but the reasoning is joning positive factors into one value that may range from 4 to 40 with acid smog. Euristically it copes with resistance in Indian flora, but the units are not Standard ((mgDw-1)^2,log(1/H)in Fw, %RWC..)It is advisable to give a table with single variables and use fumigation controls.
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what is the efiecnt method for air pollution toxicity measurements directly, with bacteria.?
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