o3 and volatile organic compounds vocs

... national and regional concern This report is on volatile organic compounds (VOCs) in ground water and drinking-water supply wells It is a synthesis of NAWQA and other investigations Fifty-five VOCs ... Background and National Significance 1.  What are VOCs? VOCs are a subset of organic compounds with inherent physical and chemical properties that allow these compounds to move between water and air ... and use of manmade organic compounds, many of which are classified as VOCs, increased by an order of magnitude between 1945 and 1985.(5) Some VOCs have had, and continue to have, very large and...

Ngày tải lên: 14/03/2014, 19:20

... commencing with section 94500, and (2) low vapor pressure -volatile organic compounds (LVP-VOC) as that term is defined in section 94508(a), and (3) the reactive organic compounds (ROC) contained in ... METHOD 310 DETERMINATION OF VOLATILE ORGANIC COMPOUNDS (VOC) IN CONSUMER PRODUCTS AND REACTIVE ORGANIC COMPOUNDS IN AEROSOL COATING PRODUCTS APPLICABILITY 1.1 This ... 100 Where: V = weight fraction of non-exempted volatile organic compounds in the non-propellant portion n = number of non-exempted volatile organic compounds in the non-propellant portion WL =...

Ngày tải lên: 14/03/2014, 20:20

... inflammatory and oxidative lung processes, and different volatile organic compounds (VOCs) of endogenous or exogenous origin have been analyzed to study lung diseases [1] and characterize environmental and ... defined standard operating procedures, and validated analytical methods of VOC collection and analysis The factors affect the SPME process, such as adsorption and desorption times and sampling ... The VOCs were separated on an Equity™-1 column (30 m, 0.25 mm i.d., 1.0 µm film, Supelco) and acquired in full-scan mode in 40–350 m/z range Thirteen VOCs (seven aliphatic and six aromatic compounds) ...

Ngày tải lên: 12/08/2014, 18:21

... burning oil, gas, and coal, and from discharges of ethylbenzene from factories Ethylbenzene gets into the soil by spills of gasoline or other fuels and poor disposal of industrial and household wastes ... during forest fires Xylene is used as a solvent and in the printing, rubber, and leather industries It is used as a cleaning agent and a thinner for paint and varnishes Xylene is a major component ... adhesives, and rubber, and in some printing and leather tanning processes Toluene is a major component of JP-8 fuel Toluene enters the air through automobile exhaust It can enter surface water and groundwater...

Ngày tải lên: 14/02/2014, 03:20

... Generate a random series r with the same length as c (7292 elements) and variance νr2 ) (b) Perform FFT on c and r, and calculate their magnitude spectra and call them mfc and mfr (c) Plot mfc and mfr, ... contribution from the northwest and a spike in the south The motor vehicles on highways 225 and 146 and Spencer Hwy may increase the concentrations of c9- and c10-benzenes and may be a reason for the ... temperature will not only speed up the vaporization of VOCs but also change the chemical properties of VOCs and enhance the reactions between VOCs and oxidants in the air It is relatively difficult...

Ngày tải lên: 22/03/2014, 14:20

... mixture of volatile organic compounds Neurotoxicol Teratol 12,649-652 Rothweiler H., Wager P.A and Schlatter C., 1992 Volatile organic compounds and some very volatile organic compounds in new and reccntly ... Classzjication of indoor organic pollutants (WHO, 1989) Category Description Abbreviation Very volatile (gaseous) organic compounds VVOC Volatile organic compounds VOC organic compounds associated ... assessing the effects of volatile organic compounds (VOCs) in indoor air on comfort and health is reviewed Advantages and disadvantages of a TVOC (Iota1 Volatile Organic Compounds) concept are...

Ngày tải lên: 28/03/2014, 19:20

... characterization of volatile organic compounds (VOCs) in the MCMA, both on the ground and aloft and on the emission, transport, and transformation of VOCs downwind of the metropolitan area Measurable VOCs as ... al.: Chemical evolution of volatile organic compounds Fig The top 20 compounds measured at T0 (top panel) and T1 (lower panel) in terms of mixing ratios between 09:00 and 18:00 local time averaged ... VOC compounds is 19.7 s−1 Atmos Chem Phys., 10, 2353–2376, 2010 2362 E C Apel et al.: Chemical evolution of volatile organic compounds Fig The top 20 compounds measured at T0 (top panel) and...

Ngày tải lên: 28/03/2014, 20:20

... photphat -Quá trình xử lí H2S Na2CO3 dựa sở phản ứng sau: H2S + Na2CO3 = NaHS + NaHCO3 -Tiếp theo phản ứng thu hồi lưu huỳnh Natri vanadat (NaVO3 ) NaHS + H2S + 4NaVO3 + ½ O2 = Na2V4O9 +NaOH + 3S ... H2O = NaHS + NaOH -Song song với phản ứng trên, NaOH tác dụng với CO2 CO2 + NaOH = NaHCO3 NaHCO3 + NaOH = Na2CO3 +H2O -Ngoài phản ửng khử H2S dung dịch xảy trình oxi hóa natri sunfua thu từ phản ... huỳnh e Xử lý khí H2S chất hấp thụ oxit sắt Fe 2O3 -Đây phương pháp cổ điển dựa cở sở phản ứng sau : Fe 2O3 + H2S = Fe2S3 + 3H2O 2Fe2S3 + O2 = 2Fe 2O3 + 6S - Sau bão hòa H2S oxit sắt hoàn nguyên...

Ngày tải lên: 12/04/2015, 14:24

... measured VOCs are calculated according to t¼ kOH ½OHŠ þ kO3 O3 Š þ J ð5Þ where kOH and kO3 are the rate constants for reaction with OH and O3 [Atkinson, 1994; Sander et al., 2002], and J is ... in the organic aerosol, likely reflecting a common source, i.e., photochemical production of oxygenated VOCs and secondary organic aerosol The relationship between the organic aerosol and VOCs ... communication), and was analyzed daily to check for blank problems and contamination for all measured compounds Precision, accuracy and detection limits for measured compounds, along with the 0.25, 0.50 and...

Ngày tải lên: 05/03/2014, 20:20

... strong androgen agonist (Larsson et al., 2006) TBECH was shown to bind to and activate the human androgen receptor in human liver cells Further, co-exposure to the androgen dihydrotestosterone and ... plasticizer for flexible polyvinylchloride and for use in wire and cable insulation, film and sheeting, carpet backing, coated fabrics, wall coverings and adhesives Annual U.S production/imports ... sample amount and the LC-MS/MS equipment used Weiss et al (2004) found HBCD in both maternal and cord blood in the Netherlands HBCD in maternal blood was measured during weeks 20 and 35 of pregnancy...

Ngày tải lên: 05/03/2014, 20:20

... identified and measured the mixing ratios of major volatile organic compounds emitted by pigs and sheep in Germany The diurnal variations of carbon dioxide, nitrous oxide, methane, and ammonia ... Quellgruppe Landwirtschaft Braunschweig : FAL, 279 p, Landbauforsch Völkenrode SH 260 Filipy J, Rumburg B, Mount G, Westberg H, Lamb B (2006) Identification and quantification of volatile organic compounds ... oxide and carbon dioxide, this paper identifies major VOCs emitted from sheep and pig buildings We also present the estimated mass release rates of some VOCs from these buildings Materials and...

Ngày tải lên: 05/03/2014, 21:20

... was designed for preconcentration and separation of oxygenated, aromatic, and halogenated VOCs, NMHCs larger than C6, and some other VOCs such as acetonitrile and dimethylsulfide, on a DB-WAX ... C10 volatile organic compounds above a Sierra Nevada ponderosa pine plantation, J Geophys Res., 104(D17), 21,247 – 21,262 Lim, H J., and B J Turpin (2002), Origins of primary and secondary organic ... Schlapfer, and S Wunderli (1998), Emission factors from road traffic from a tunnel study (Gubrist tunnel, Switzerland) part III: Results of organic compounds, SO2 and speciation of organic exhaust...

Ngày tải lên: 05/03/2014, 21:20

... was observed for nm SrRuO3 films on LaAlO3, BaTiO3 and LSAT, while thicker (10 – 20 nm) films had metallic behaviour like nm films on GdScO3, DyScO3 and SrTiO3 substrates (Fig 1.12) These results ... found in Chapter In Section 3.1 the preparation process and conditions of atomically flat SrTiO3(001), DyScO3(110) and NdGaO3(110) surfaces and the measurement of the termination layer of the surfaces ... properties ((K,Ba)BiO3) [1], piezoelectric properties (Pb(Zr,Ti )O3) [2] relaxor ferroelectric properties (Pb(Nb,Mg )O3) [3], (Na,Bi)TiO3) [4], dielectric properties (BaTiO3 [5], SrTiO3 [6]), conductive-ferroelectric...

Ngày tải lên: 14/03/2014, 19:20

... C J Popp, and R S Martin (2004), Biogenic emissions and ambient concentratiosn of hydrocarbons, carbonyl compounds and organic acids from Pondorosa pine and Cottonwood trees of rural and forested ... and R C MacDonald (1987), Acetaldehyde and ethanol biosynthesis in plants, Plant Physiol., 84, 1204 – 1209 Kirstine, W., I Galbally, Y Ye, and M Hooper (1998), Emissions of volatile organic compounds ... concentrations and large emission rates have been measured in many forested ecosystems and grass land areas [Kimmerer and MacDonald, 1987; Kelsey, 1996; Lamanna and Goldstein, 1999; Schade and Goldstein,...

Ngày tải lên: 14/03/2014, 20:20

... Method 5035, “Closed-System Purgeand-Trap and Extraction for Volatile Organics in Soil and Waste Samples,” and Method 5021, Volatile Organic Compounds in Soils and Other Solid Matrices Using Equilibrium ... Volatile Organic Compound Concentration in Soil and Solid Matrices 8.0 REFERENCES American Society for Testing and Materials (2003) Standard Guide for Sampling Waste and Soils for Volatile Organic Compounds, ... Region has developed technical guidelines to help ensure that sampling and analyzing for Volatile Organic Compounds (VOCs) in soil and solid matrices are conducted in a manner that achieves accurate,...

Ngày tải lên: 14/03/2014, 20:20

... units (THUs) for a range of volatile organic compounds (VOCs) and aldehydes including formaldehyde, and 2) determine materials specific emission factors of these compounds from individual surface ... individual and total volatile organic compounds in residential indoor air of Schleswig-Holstein, Germany” J Environ Monit Vol 6, 745-752 Hodgson, A.T (1999) Common Indoor Sources of Volatile Organic Compounds: ... (2000) "Volatile Organic Compound Concentrations and Emission Rates in New Manufactured and Site-Built Houses", Indoor Air, 10, 178-192 Hodgson, A.T and H Levin (2003) Volatile Organic Compounds in...

Ngày tải lên: 22/03/2014, 14:20

... solutions 3.12 Calibration Standard (CAL) A solution prepared from the primary dilution standard solution or stock standard solutions and the internal standards and surrogate analytes The CAL ... mammalian carcinogens Pure standard materials and stock standard solutions of these compounds should be handled with suitable protection to skin, eyes, etc EQUIPMENT AND SUPPLIES (All specifications ... rules and land disposal restrictions The laboratory using this method has the respons-ibility to protect the air, water, and land by minimizing and controlling all releases from fume hoods and...

Ngày tải lên: 22/03/2014, 14:20

... Indoor exposures to toxic and irritating volatile organic compounds (VOCs) are of general concern Residences are particularly important exposure environments for these compounds because people ... less volatile VOCs would be expected to have lower emission factors at low air change rates due to sorption and re-emission effects However, some of the more volatile compounds (e.g., pentanal and ... direct and immediate effects The influence of indoor temperature and relative humidity on the emissions and concentrations of formaldehyde has been studied and modeled in chamber experiments and...

Ngày tải lên: 22/03/2014, 14:20

... other hand, the field effect of the negatively charged groups (SO3- and O-) and the H-bond of the second OH with the =N will raise the second pKa2 and overcome the resonance contribution and the ... the electrostatic interaction between S and C depends on the magnitude and relative orientation of the local fields of S and C and the dielectric properties and distances through the conducting ... + [ B c + δ H (∆pK a)c ]/ T where Ac and Bc are the entropic and the enthalpic van't Hoff coefficients for the reaction center, and δH and δs are enthalpic and entropic perturbations, respectively...

Ngày tải lên: 22/03/2014, 14:20

... Experimental and Computational Hydrogen Thermochemistry of Organic Compounds Experimental and Computational Hydrogen Thermochemistry of Organic Compounds Long Island University, USA l ... Heats of Hydrogenation Practical and historical aspects of experimental determination of the enthalpies of hydrogenation and formation \ydH29S and Af H29i of organic compounds, primarily hydrocarbons, ... mechanical effects and molecular strain, for example, resonance stabilization of aromatic compounds, conjugative stabilization of linear polyenes and polyynes, and steric effects in cisand trans- isomers...

Ngày tải lên: 01/04/2014, 10:53