NOx Values Research Articles

Ozone pollution characteristics and sensitivity analysis using an observation-based model in Nanjing, Yangtze River Delta Region of China

Ground-level ozone (O3) has become a critical pollutant impeding air quality improvement in Yangtze River Delta region of China. In this study, we present O3 pollution characteristics based on one-year online measurements during 2016 at an urban site in Nanjing, Jiangsu Province. Then, the sensitivity of O3 to its precursors during 2 O3 pollution episodes in August was analyzed using a box model based on observation (OBM). The relative incremental reactivity (RIR) of hydrocarbons was larger than other precursors, suggesting that hydrocarbons played the dominant role in O3 formation. The RIR values for NOX ranged from –0.41%/% to 0.19%/%. The O3 sensitivity was also analyzed based on relationship of simulated O3 production rates with reductions of VOC and NOX derived from scenario analyses. Simulation results illustrate that O3 formation was between VOCs-limited and transition regime. Xylenes and light alkenes were found to be key species in O3 formation according to RIR values, and their sources were determined using the Positive Matrix Factorization (PMF) model. Paints and solvent use was the largest contributor to xylenes (54%), while petrochemical industry was the most important source to propene (82%). Discussions on VOCs and NOX reduction schemes suggest that the 5% O3 control goal can be achieved by reducing VOCs by 20%. To obtain 10% O3 control goal, VOCs need to be reduced by 30% with VOCs/NOX larger than 3:1.

Evaluation of Exterior Air Quality Between 2014-2016 in Tekirdag

Hava kirliliği, sağlık için en büyük çevresel risklerden biridir. 2012'de her dokuz ölümden bir tanesi hava kirliliği ile ilgili koşulların sonucu olmuştur. Bu ölümlerin yaklaşık 3 milyonu sadece dış ortam hava kirliliğine atfedilebilir. Amaç: Bu çalışmada amacımız; Tekirdağ il genelindeki hava kirliliği ölçüm istasyonlarından elde ettiğimiz PM10, PM2.5, SO2 ve NOX değerlerinin 2014, 2015 ve 2016 yılları arasındaki farklarını, yaz-kış ve 24 saat içindeki değişimlerini incelemektir. Gereç ve Yöntemler: Çalışmamız kesitsel ve tanımlayıcı araştırmadır. Bu çalışmanın verileri, 1 Ocak 2014-31 Aralık 2016 tarihleri arasındaki Çevre ve Şehircilik Bakanlığı’na ait www.havaizleme.gov.tr sitesinden alınan saatlik ölçüm değerleridir. Elde edilen değerler Avrupa Birliği (AB) ve Dünya Sağlık Örgütü’nün (DSÖ) PM10, PM2.5, SO2 ve NOX değerlerinin saatlik ve 24 saatlik ortalama sınır değerleri ile karşılaştırılmıştır.Bulgular: Çalışmamızda Tekirdağ il genelinde PM10, PM2.5, SO2 ve NOX kirleticilerin hemen hemen tüm yıllarda ortalamaları DSÖ sınır değeri üzerinde bulunmuştur. Ayrıca çalışmamızda SO2, PM10, PM2,5 ve NOX değerlerinin aylık ortalamaları 3 yılda da özellikle kış dönemi içindeki aylarda (ocak, şubat, mart, ekim, kasım, aralık) hem DSÖ hem de AB 24 saatlik ortalama limitlerinin çok üzerindedir. Bununla birlikte araştırmamızda hava kirliliğinin kış döneminde yaz dönemine göre anlamlı olarak arttığı görülmektedir (p<0,05). Sonuç: Tekirdağ il genelinde DSÖ ve AB sınır değerleri baz alındığında SO2, PM10, PM2.5 ve NOX kaynaklı hava kirliliği mevcut olup kirlilik kış döneminde anlamlı şekilde artmaktadır. Tekirdağ il genelinde görülen sağlık sorunlarının muhtemel nedenleri arasında hava kirliliği akla gelmelidir. SO2, PM10, PM2.5 ve NOX kaynaklı hava kirliliğinin engellenebilirse birçok sağlık probleminin önlenmesi mümkündür. Tekirdağ il genelinde hava kalitesi ölçüm noktalarının ve ölçüm yapılan kirlilik parametrelerinin sayısı yetersiz olup sayıları ve nitelikleri artırılmalıdır. Hava kirliğinin kaynaklarının tespit edilmesine ve muhtemel sağlık etkilerine yönelik bilimsel çalışmaların sayıları arttırılmalıdır.

Effect of carbon nanotube material in diesel engine with exhaust gas recirculation

ABSTRACT The demand for biodiesel oil or vegetable oil leads to the depletion of reserves of fossil fuel. Due to global political turmoil, this promoted an exponential hike in crude oil prices. Carbon nanotubes (CNTs) will build the proportion of carbon–oxygen in the biodiesel energizers by improving the burning execution of diesel–biodiesel mixes. CNT is absolutely a carbon substance developed fit as a fiddle with nanometer size and its scattering into the fuel will help as ignition impetus. The experiment is carried out to make an analysis of emission and to find out the effect on the performance by using exhaust gas recirculation (EGR), using biodiesel B20TCSAO with multiwalled carbon nanotube (MWCNT40ppm) and diesel with various EGR percentages (5%, 10%, 15%, and 20%) at different loads. The NOx value for MWCNT40ppmTCSAO was 1,023 ppm without EGR and 828 ppm at full load. The oxides of nitrogen are reduced by 20% using MWCNT with EGR compared to that without EGR. The performance of MWCNT increases by 5%.

Real time estimation of emissions in a diesel vehicle with neural networks

Several studies in literature have shown how real-world emissions strongly depend on driving condition, driving style, ambient temperature and humidity, etc. so that they are significantly different from the values measured on test benches over standard driving cycles. This concern, together with the so-called Diesel-gate, has caused the introduction in Europe of an innovative procedure for the registration of vehicle based on real driving emissions (RDE) measured with a portable emission measurement system (PEMS). PEMS devices are bulky and very expensive, therefore they cannot be extensively for an actual real time monitoring of emissions. To solve this problem, the present work proposes a Neural Network model based on the interpolation of the time-histories of driving conditions (speed, altitude, ambient temperature, humidity and pressure) and emissions measured on a diesel start-and-stop vehicle while performing a series of RDE tests. Two different approaches are proposed. The first one calculates the emissions on the basis of the vehicle motion (speed and altitude profile, ambient conditions). The second one models the engine block using as input the ambient conditions, the load and the rpm of the engine as derived from the OBD-II scanner. The output of both models are the flow rates and cumulated values of CO2 and NOx. Note that the inputs of the two models are signal that can easily obtained on-board without additional sensors.

Research on GTE-110 gas turbine operating modes for limiting nitrogen oxide emissions of ccgt power units

Gas turbines are actively used as a part of combined-cycle power units having less impact on the environ-ment than installations operating on other types of fuel. However, their emissions contain harmful carbon compounds and nitrogen oxides. Some research studies considered the effect of emissions upon changes in the coefficient of excess air. At the same time, no attention was paid to the influence of other operational parameters and technological limitations associated with the safe operation of combined-cycle CCGT equipment, and no assessment was made of the impact of climatic factors on environmental indicators. Thus, it is important to conduct separate studies to assess the influence of regime and climatic factors on the stability of the combustion process in the combustion chamber of a gas turbine, on the environmental performance of the installation and the compliance of these indicators with the standards. The research used data from the control system archive, and a simulation model was developed in the SimInTech environment. The following assumptions are made in the model: the fuel composition does not change and it enters the single combustion zone without separation into the pilot and central zones of the combustion chamber. The methodology for calculating emissions is reduced to dividing their volume into NO and NO2 due to the transformation of nitrogen oxides in the air. Subsequently, the values of the total concentration are recalculated to a single NOx value. A simulation model for calculating emissions has been obtained. The effect of excess air on nitrogen oxide emissions considering the technological zones of gas turbines of outdoor air temperature (To.a) from –20 to +30 оС and the power from 48 to 110 MW has been assessed. It has been shown that near the nominal load the maximum NOx emission are observed. In general, the results obtained indicate that the requirements for NOx emission standards are met in the entire operating range of gas turbine load changes. However, the reserve of a possible deviation of emissions to a critical level is only 10 %. The verification of the developed model is based on operational trends. The recommendations on operational management have been formulated for power unit operators in order to maintain an ac-ceptable level of NOx emissions.

Nitrogen isotope differences between atmospheric nitrate and corresponding nitrogen oxides: A new constraint using oxygen isotopes

Tracking of reactive nitrogen (N) sources is important for the effective mitigation of N emissions. By combining the N and oxygen (O) isotopes of atmospheric NO3−, stable isotope mixing models were recently applied to evaluate the relative contributions of major NOx sources. However, it has long been unresolved how to accurately constrain the δ15N differences between NO3− and corresponding NOx (ε(NO2→NO3−) values). Here, we first incorporated the HC oxidation (NO2 → NO3−) pathway by using Δ17O values to evaluate the ε(NO2→NO3−) values, performed on NO3− in PM2.5 collected during the day and at night from January 4–13, 2015 at an urban site in Beijing. We found that the Δ17O-based ε values (ε17O-based(NO2→NO3−)) (15.6 ± 7.4‰) differed distinctly from δ18O-based ε values (ε18O-based(NO2→NO3−)) (33.0 ± 9.5‰) so did not properly incorporate the isotopic effects of the HC oxidation (NO2 → NO3−) pathway. Based on the ε(NO2→NO3−) values, δ15N values of NOx from coal combustion (CC), vehicle exhausts (VE), biomass burning (BB), and the microbial N cycle (MC), as well as NO3− in PM2.5, we further quantified the source contributions by using Stable Isotope Analysis in R (the SIAR model). We found that the respective fractional contributions of CC-NOx and MC-NOx were underestimated by 64% and were overestimated by 216% by using ε18O-based(NO2→NO3−) values. We concluded that the new ε17O-based(NO2→NO3−) values reduced uncertainties in contribution analysis and the evaluation method for atmospheric NO3− sources.

Emission and performance analysis of DI diesel engines fueled by biodiesel blends via CFD simulation of spray combustion and different spray breakup models: a numerical study

In the current study, computational fluid dynamics code was used to perform 3D simulation of mixture formation and combustion of biodiesel fuel spray in a direct injection diesel engine. Thus, the spray atomization and combustion processes were simulated by applying the improved version of KH–RT spray breakup model coupled with advanced ECFM-3Z model for combustion. To this aim, experimental results were used first to validate the calculated values of NOx, soot, heat release rate, and in-cylinder pressure and good agreement was obtained. To develop the engine performance and reduce the emission, various models of spray breakup of biodiesel fuel were simulated, and the optimum spray breakup model was specified. Also, the accuracy of each model was determined in comparison with the experimental results. The results show that the TAB breakup model has not provided acceptable results for spray characteristics compared to the other models. Since the simulation results of in-cylinder pressure and emissions were consistent with the experimental results by the KHRT model, it could be concluded that this model has correctly predicted the size of droplets produced by spray fragmentation and penetration, and it could be used to simulate the atomization of biodiesel fuel spray under different engine conditions by adjusting the model constants.

Stable isotope ratio of atmospheric and seawater nitrate in the East Sea in the northwestern Pacific ocean

Abstract The nitrogen and oxygen isotopic values of anthropogenic NOx− (including NO2− and NO3−) are preserved in precipitation and airborne total suspended particles. Hence, isotope analyses of these atmospheric samples allow for the identification of the NOx− sources. In this study, atmospheric δ15N- and δ18O-NOx− values were measured in an eastern coastal site of South Korea over a three-year period, and compared with seawater values observed from coastal waters of the East Sea. The highest seasonal atmospheric δ15N-NOx− values were associated with wintertime air masses blowing from northeastern China, and similar to those produced by coal and biomass burning. By contrast, the lowest atmospheric δ15N-NOx− values were observed in summer, and the major source appeared to be vehicle exhaust. In addition, the reductions in the seawater δ15N-NOx− and Δ(15−18) (i.e., δ15N-NOx− minus δ18O-NOx−) values in the East Sea could be at least partially attributed to atmospheric deposition.

Integration of continuous restricted Boltzmann machine and SVR in NOx emissions prediction of a tangential firing boiler

The NOx emissions prediction modeling of a coal-fired boiler is a complicated problem because of its highly nonlinear and strongly correlated multi-variables. To address this problem, this paper presents a novel deep structure using continuous restricted Boltzmann machine (CRBM) with support vector regression (SVR). A new steady-state identification method is first established by applying kernel principal component analysis (KPCA). Subsequently the stationary samples are subjected to the stacked CRBM network for extracting implied features. The combination of the optimal features and target NOx values are further utilized for training SVR to establish the regression pzmart of the CRBM-SVR prediction model. Additionally, particle swarm optimization (PSO) is applied for optimizing hyper-parameters of SVR, and weights of CRBMs are fine-tuned with gradient descent on account of prediction errors. Compared with the existing state of the art, the proposed structure achieves a good performance of 4.83 mg/m3, 3.55 mg/m3 and 0.963 of RMSE, MAE and R2.

Emission and Heavy Metal Content Characteristic of Densified Refused Derived Fuels of Oil Sludge and Biomass Combination as an Alternative Fuel for Cement Plant

Hazardous Waste such Oil Sludge combined with biomass (coconut shell and rice husk) was utilized as an alternative fuel in cement plant in form of Densified-Refused Derived Fuel (D-RDF). D-RDF were Co-Processed with primary fuel into Rotary Kiln in order to reduce usage of fossil fuel and eliminate the hazardous waste by thermal treatment, meanwhile to recover the energy contained in the D-RDF, the utilization of these waste are expected without causing adverse effect into the environment. Co-Processing of D-RDF as alternative fuels into cement plant kiln must follow the regulation applied in Indonesian Environment and Forestry Minister regulation 19/2017 and European Union for Responsible Incineration and Treatment of Special Waste (EURITS). Based on previous research, D-RDF composition of oil sludge and biomass at 1:1 ratio with 5% starch addition was choose as they give best calorific value at 6000 kcal/kg. The objective of these research are to observe the emission caused by the utilization of these D-RDF and potential effect into cement or clinker product. The result show NOx and CO value are meet the standard requirement by government regulation meanwhile SO2 value which are 1251 mg/Nm3 and 1500 mg/Nm3, over the regulation standard which is 650 mg/Nm3. This issue could be overcome in the plant with pre treatment of D-RDF and utilization of Bag House Filter or Electostatic Precipitator before release the emission to the stack. Trace element analysis of D-RDF ashes (As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Se, Sn dan Zn) show the result are meet the EURITS regulation, which mean utilization of D-RDF will not give quality deffect to cement or clinker product.

Pollutant emissions of a biomass gasifier inside a multifuel energy plant

Several benefits in clean energy and pollutant emissions can be offered from biomass energy application. This research analyzes a biomass gasifier installed at the University of Perugia and presents the description of a multifuel biomass energy plant with all its components: the combustion chamber and the heat exchanger, installed to supply the thermal input to the turbine, with 100 kW electric power and 1 MW thermal power.The application of a Computational Fluid Dynamics (CFD) prediction model can help to better understand the knowledge on chemical and thermofluidodynamic features linked to pollutant emissions. A numerical modelling based on Ansys Fluent code is realized with the aim to reproduce the behaviour of the gasifier. Two different stoichiometric woodchips:air ratios are taken into account in the numerical calculations. Experimental tests have been conducted to validate the results of the numerical analysis.The obtained results show that the experimental and the numerical analysis with the 1:5 stoichiometric ratio are comparable. The influence of the woodchips:air stoichiometric ratio on the temperature distribution that may be reached inside the gasifier is highlighted. The relationship between woodchips:air stoichiometric ratio, temperature and NOx emissions is considered. Furthermore, a comparison between the values of NOx and CO pollutants obtained with the numerical model and experimental tests has been done. The gasification process contributes to the production of renewable energy and it can be combined with other energy cycles (e.g. Organic Rankine Cycle).The novelty of the work consists in the definition and validation of a method for the analysis of the operating temperatures of the gasifier to verify how they can be combined with other heat exchange systems and in the analysis of the pollutants during the gasification process.

Effects of Citrulline Malate and Beetroot Juice Supplementation on Blood Flow, Energy Metabolism, and Performance During Maximum Effort Leg Extension Exercise.

Trexler, ET, Keith, DS, Schwartz, TA, Ryan, ED, Stoner, L, Persky, AM, and Smith-Ryan, AE. Effects of citrulline malate and beetroot juice supplementation on blood flow, energy metabolism, and performance during maximum effort leg extension exercise. J Strength Cond Res 33(9): 2321-2329, 2019-Citrulline malate (CitMal) and beetroot juice (BEET) are increasingly popular ergogenic aids, but few studies have rigorously investigated their effects on resistance exercise performance and underlying mechanisms. The current randomized, double-blind, crossover study evaluated the effects of CitMal and BEET supplementation on blood flow, metabolic efficiency, and performance during maximal isokinetic leg extension exercise. After familiarization, 27 recreationally active men (age: 22 ± 4 years) completed 3 visits in which subjects ingested a treatment beverage (CitMal [8 g], BEET [400-mg nitrate], or placebo [PLA]), followed by a 2-hour rest period, warm-up, and 5 sets of 30 concentric leg extensions. Before and after exercise, ultrasound was used to measure diameter (aDIAM) and blood flow (aBF) of the superficial femoral artery, along with cross-sectional area and echo intensity of the vastus lateralis. Plasma analytes (lactate, nitrate/nitrite [NOx], and urea nitrogen [BUN]) were also assessed at these times, and indirect calorimetry was used to measure energy expenditure and respiratory exchange ratio before and during exercise. Resting NOx values were higher in BEET (233.2 ± 1.1 μmol·L) compared with CitMal (15.3 ± 1.1, p < 0.0001) and PLA (13.4 ± 1.1, p < 0.0001). Postexercise NOx values, adjusted for resting differences, were higher in BEET (86.3 ± 1.2 μmol·L) than CitMal (21.3 ± 1.1, p < 0.0001) and PLA (18.1 ± 1.1, p < 0.0001). No other variables were affected by treatment (all p > 0.05). While BEET increased NOx, neither treatment was found to enhance performance, blood flow, metabolic efficiency, nor the hormonal response to leg extension exercise.

Experimental Explorations of Dual Fuel CI Engine Operating with Guizotia abyssinica Methyl Ester–Diesel Blend (B20) and Hydrogen at Different Compression Ratios

The foremost difficulties related to the use of biodiesel in CI engine are lower BTE and insignificant smoke emissions. These difficulties related to using biodiesel can be resolved by inducting gaseous fuels simultaneously along with primary fuel in CI engine. This paper confers the effect of the compression ratio on the engine on the performance, combustion, and emission characteristics of Niger seed (Guizotia abyssinica) oil methyl ester blend (B20) with simultaneous injection of hydrogen (gaseous fuel) at different flow rates. The studies were carried out on a variable-compression-ratio single-cylinder 4-stroke CI engine at 1500 rpm with three different compression ratios of 16, 17.5, and 18.5 and at three different hydrogen flow rates of 5 lpm, 10 lpm, and 15 lpm. The injection of hydrogen notably increased the brake thermal efficiency (BTE) with a significant reduction in brake-specific fuel consumption (BSFC). The combustion characteristics cylinder pressure (CP), net heat release rate (NHRR), and rate of pressure rise (RoPR) also increased drastically. Also, the emission of CO, UHC, and smoke opacity were reduced significantly with spike in NOx emissions. The comparable trends were followed at all the three compression ratios, and the CR 18.5 has shown improved results at a flow rate of 15 lpm. At 15 lpm and CR 18.5, the BTE, CP, NHRR, RoPR, and NOx values were increased by 7.3%, 7.68%, 12.36%, 21.08%, and 56.8%, respectively. Further, the BSFC, CO, UHC, and smoke opacity were reduced by 9.15%, 84.95%, 69.9%, and 59.78% respectively.

Production of rice bran methyl esters and their engine characteristics in a DI diesel engine

The study aims to convert rice bran oil into biodiesel by transesterification and to test the biodiesel–diesel blends in a direct injection compression ignition engine. Methanol (alcohol) and NaOH (catalyst) are used for the process of transesterification. The engine testing was conducted by varying the injection timings at 21°BTDC, 24°BTDC and 27°BTDC with blends of B20, B40, B60, B80 and B100. The engine characteristics (performance, combustion and emission) of ricebran methyl ester are analysed. When comparing the injection timings, the blends B80 and B100 consume more fuel than the other blends. While propelling the injection timing, for example, at 27° BTDC the level of CO emissions is less compared with other injection timings. While retarding the timing for example, at 21° BTDC, the CO emissions are significantly high for diesel, B20 and B40. High NOx values are recorded for all the of biodiesel blends.

Modelling and experimental study on performance and emission characteristics of citrullus colocynthis (thumba oil) diesel fuelled operated variable compression ratio diesel engine

This experimental investigation aimed to depict the effects of varying loads at various compression ratios with thumba methyl esters in different proportions as fuel on a variable compression ratio diesel engine. Series of tests were conducted on a single cylinder, 3.6 kW, water cooled, variable compression ratio, stationary diesel engine, as per the full factorial design to measure the performance and emission characteristics. The engine load, compression ratio and blending ratio for citrullus colocynthis (thumba oil) based diesel were taken as input parameters and their effects on engine performance and emissions characteristics such as BTE, BSFC, HC, NOx & CO were investigated experimentally and analytically. Experimental data was analysed and modelled using the full factorial design in three different stages to achieve the optimum results for performance and emission characteristics. For each stage, second order and third order estimate models were developed and were checked for assumptions of Analysis of Variance i.e. normality & homogeneity of data. The optimum performance & emission characteristics were observed with 20% thumba-diesel blend, at a compression ratio of 18 at maximum load. It was found that the optimum values of BSFC, BTE, HC, CO & NOx was 0.456 kg/kWh, 19.725%, 38.432 ppm, 0.026% and 348.744 ppm respectively at load of 10 kg, CR of 18, and blend percentage of 20. A good agreement between experimental results and predication results depicts that the developed models can be used with competence to optimize similar type diesel engine parameters using citrullus colocynthis (thumba oil) blend without engine modification.

Serum nitric oxide metabolites and hard clinical endpoints: a population-based prospective study

Objective. Limited data are available regarding prognostic value of nitric oxide metabolites (NOx) for clinical hard end points. In this study, we defined optimum cut-off values of serum NOx for predicting all-cause and cardiovascular disease (CVD) mortality events and prospectively investigated their hazards in the presence of traditional risk factors. Design. Serum NOx concentrations were measured at baseline (2006–2008) and 3520 adult men and women were followed during 7.7 years for all-cause and cardiovascular disease (CVD) mortality. To determine the optimal cut-off points of serum NOx, the receiver operator characteristic (ROC) curve analysis was used. Multivariate Cox proportional hazard models were used to estimate the hazard ratios (HRs) with 95% confidence intervals (95% CIs) of all-cause and CVD mortality below and above the defined optimal cut-off points of serum NOx. Results. Mean age of participants was 44.5 ± 16.0 years at baseline and 40.2% were male. Median (inter-quartile range) of serum NOx levels was 25.0 µmol/L (19.0–37.0), at baseline. The optimal cut-off points of serum NOx levels for predicting CVD and all-cause mortality were 30.5 and 32.5 µmol/L, respectively. In the presence of age, sex, body mass index, smoking, type 2 diabetes, hypertension, and history of CVD, a significant increased risk of CVD mortality (HR = 1.98, 95% CI = 1.10–3.58) and all-cause mortality (HR = 1.52, 95% CI = 1.05–2.21) was observed for serum NOx values higher than their cut-offs. Conclusion. Serum NOx level may be predictor of CVD mortality and death, in general populations.

Numerical investigation of airflow patterns and pollutant dispersions induced by a fleet of vehicles inside road tunnels using dynamic mesh Part Ⅱ: Pollutant dispersion and exposure levels

Following our simulation results in Part I (Song and Zhao, 2019), in this study we continued to analyze pollutant dispersion patterns and exposure levels when a fleet of vehicles passed through a 450-m long tunnel by employing the Realizable k–ε model and pollutant transport equation together with the dynamic mesh technique. The same 450-m-long tunnel model with a 450-m extension from the outlet in the driveway direction in Part I was developed; it contained 36 gasoline-powered vehicles in nine rows with four vehicles per row. The transient pollutant dispersion profiles were validated by comparing the simulation results to field-measurement data in a real tunnel. The simulation results show that volume-averaged CO and NOx concentrations inside the tunnel were less than the exposure limit in China (150 ppm for CO and 1 ppm for NOx) at 60 km/h and 40 km/h, which is in accordance with the study in Part I. However, in the breathing zone (0.5–1.5 m in height), accumulated pollutants and averaged CO and NOx concentrations were 0.85–2.44 times the exposure limit in China, even at 60 km/h and 40 km/h. The personal intake fraction (P_IF) CO and NOx values inside the tunnel in this study were at least an order of magnitude higher than those outdoors, including in Beijing, Hong Kong, and the US urban areas. The results indicate that occupant exposure risk is relatively high inside the tunnel and ventilation systems should continue to work to decrease the exposure levels in the breathing zone, even when vehicles move at medium or high speeds inside the tunnel.

Influence of meteorological factors on the secondary contamination of atmospheric air by formaldehyde ( on the example of the city of Kyiv).

Many authors on the basis of researches give information that motor transport is the basic source of contamination of atmospheric air of cities of Ukraine. This work touches on the estimation of the level and dynamics of contamination of m. Kyiv extras from a motor transport and influence of meteorological factors of locality on the degree of atmospheric contamination (including secondary one as a result of actinic transformations). Authors set connections between the components of SO, Nox, CHOH, and ambient temperature, on the basis of the analysis of the last five years of statistical information of basic components contaminations from motor transport, which take part in the formation of actinic transformations. The authors found out close cross-correlation connection between the molecules of Nox, CHOH, and average monthly values of temperature on the basis of the analysis of these monitoring supervisions. Also, there were investigational processes of the formation of molecules of SNON depending on other climatic factors of the city of Kyiv, namely: the humidity of the air, speed of the wind, and index of acidity of the atmosphere (pH). It is well-proven that formation of formaldehyde in mid-air above motor transport ways the degree of acidification of atmospheric fallouts influences mediated. However, have a direct cross-correlation connection between the relative humidity of air and the speed of the wind. Temperature terms play a key role in forming the secondary contamination formaldehyde above motor transport overpasses and he takes into account other climatic factors of locality mediated. Speed of reaction of the transformation of hydrocarbons in formaldehyde at neutral meteorological terms is considered on the example of the motor-car upshot of the Darnicka square. The decision of equalization of the speed of transformation of extras of hydrocarbons is found in formaldehyde by the decision of equalization of Arreniusa. This method can be applied to other cities of Ukraine. The conducted researches will allow to promote ecological strength security on the urbanized territories by the improvement of questions of acceptance of administrative decisions at building and reconstruction of motor-car overpasses of the city, and also at forming of strategic plans of ecological development of city and setting of nature protection measures.

Comparison of regulated emission factors of Euro 6 LDV in Nordic temperatures and cold start conditions: Diesel- and gasoline direct-injection

Local air pollution in Norwegian wintertime is characterized by an increase in NO2 concentrations, due to poor dispersion and increased vehicle emissions. The focus of this study is therefore the characterisation of exhaust vehicle emissions in cold ambient temperatures. Euro 6 Gasoline Direct Injection (GDI) cars and diesel cars were tested in the laboratory in cold temperatures, including with cold start of the engine. Results show high emissions of CO2, PM and NOx. For the first time, we report also elevated NOx values for GDI vehicles. Further measurements are required to investigate whether these results are the beginning of a new trend of high NOx emissions from GDIs, or if these results represent singular events, but it may indicate that further NOx traps or catalysts are required for these vehicles. Understanding the relationship of cold ambient temperatures and vehicle emissions is also particularly important for air quality dispersion modelling, which do not currently account for emission temperature dependence.

Altered Venous Blood Nitric Oxide Levels at Depth and Related Bubble Formation During Scuba Diving.

Introduction: Nitric oxide (NO) plays an important role in the physiology and pathophysiology of diving, and the related endothelial dysfunction and oxidative stress roles have been extensively investigated. However, most available data have been obtained before and after the dive, whilst, as far as we know, no data is available about what happens during the water immersion phase of dive. The scope of this study is to investigate the Nitrate and Nitrite (NOX) concentration and the total plasma antioxidant capacity (TAC) before, during and after a single SCUBA dive in healthy scuba diving volunteers, as well as to look for evidence of a possible relationship with venous gas bubble formation.Materials and Methods: Plasma, obtained from blood of 15 expert SCUBA divers, 13 male and 2 female, was investigated for differences in NOX and TAC values in different dive times. Differences in NOX and TAC values in subjects previously known as “bubble resistant” (non-bubblers – NB) and “bubble prone” (Bubblers – B) were investigated.Results: We found a statistically significant increase of NOX plasma concentration in the “bottom blood draw” and in the “safety stop blood draw” as compared to the basal pre diving condition. We did not find any difference in NOX plasma concentration between the basal value and the post diving samples. We did not find any significant statistical difference in TAC in the bottom blood sample, while the safety-stop and the post-dive samples showed higher TAC values compared with the basal value. We did not find any difference in NOX and TAC mean values between non-bubblers and Bubblers.Discussion: Our protocol, by including underwater blood drawing, allowed to monitor plasma NOX changes occurred during diving activity, and not only by comparing pre and post diving values. It is particularly interesting to note that the increased NOX values found at the bottom and at the safety stop were not observed at post dive sampling (T0, T30, T60), showing a very rapid return to the pre-dive values. In this preliminary study we did not find any relationship between bubble formation and changes in NOX parameters and TAC response.