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The synchronous removal of soot particles and NO x using high-performance catalysts is a research hotspot in the catalytic purification of diesel engine exhaust. In this paper, glucose is used as a complexing agent to successfully prepare a series of praseodymium and/or potassium doped La–Ni-based perovskite catalysts. The La 0.9 Pr 0.05 K 0. 05 NiO 3 catalyst exhibits the best catalytic performance when NO 2 is present in the environment, with values of T 10 , T 50 , and T 90 at 287, 331, and 361 °C, respectively. The CO 2 selectivity reaches over 98% and has good thermal stability. Through characterization experiments, it was found that the co-doping of Pr and K can lead to the formation of oxygen vacancies by changing the valence state of Ni atoms, thereby increasing the adsorption and activation centers of reactive oxygen species, and enhancing the oxygen storage capacity of the catalyst through the redox cycle between Pr3+ and Pr4+. • A novel porous soot catalytic material was prepared using bimetallic doped perovskite. • Bimetal doping increases the active oxygen and oxygen vacancy contents of perovskite. • Conduct comprehensive tests on the characterization and properties of materials. • The prepared materials exhibit excellent catalytic and thermal stability performance. • The required materials for preparation are cheap and green. [ABSTRACT FROM AUTHOR]

Metabolites of polycyclic aromatic hydrocarbons measured in human samples are often used as biomarkers of exposure to diesel engine exhaust (DEE). The aim of this study was to assess the changes in urinary levels of 1-aminopyrene (1-AP) and 1-hydroxypyrene (1-OHP) and their relationship with Elemental Carbon (EC), as a component of diesel engine exhaust exposure, among a hard-rock gold-mining population. Urine samples were collected at the beginning and end of a 12-hour work shift from 100 underground and above ground gold miners. Miners were fitted with personal exposure monitoring equipment to quantify exposure to DEE, measured as Elemental Carbon (EC), across their 12-hour work shift. General linear regression assessed associations of the post-shift urinary 1-AP and 1-OHP concentrations with EC, controlling for age, gender, the pre-shift biomarker level, Body Mass Index (BMI), days on current shift, time in mining, smoking status and second-hand smoke exposure. The concentrations of 1-AP and 1-OHP increased significantly across a 12-hour mining work shift. Moreover, consistent with the sensitivity analysis, the concentration of 1-AP was significantly associated with EC after adjustments. Urinary 1-OHP, but not 1-AP was significantly associated with current smoking. Urinary 1-AP may be a more robust and specific biomarker of DEE than 1-OHP. Unlabelled Image • Elemental carbon measured as a surrogate of diesel exhaust by personal monitors • Urinary 1-AP and 1-OHP increased significantly across a 12-hour work shift. • 1-AP showed a robust and significant association with elemental carbon. [ABSTRACT FROM AUTHOR]

Abstract NTP based Ozone injection cascaded with catalysts/adsorbents for diesel exhaust treatment has been demonstrated by various researchers as a competent method for mitigation of nitrogen oxides. In this present study, one more NTP reactor is cascaded instead of catalysts/adsorbents to treat the ozone mixed diesel exhaust. While most of the laboratory studies were carried out using expensive dry air cylinders for ozone generation, in the present study, ozone has been generated from atmospheric air only. The nitrogen oxides removal/conversion efficiency of this process depends on various electrical and physical parameters. A dimensionless relation has been obtained between the ratio of summation of NO and NO 2 concentrations after treatment to that before treatment and other parameters affecting nitrogen oxides removal using dimensional analysis. Prediction of sum of NO and NO 2 concentrations with the variation in six dominant parameters have been done using nonlinear regression technique. Six parameters, i.e. ozone concentration, voltage, frequency, flow rate, temperature and discharge gap have been varied to collect the experimental data required to train and test this model. The predicted sum of NO and NO 2 concentrations are found to be well matching with the experimental results. The RMS error is found to be 3.7 % and 5.9 % respectively for training and test data. [ABSTRACT FROM AUTHOR]

Abstract Non-thermal plasma technique (NTP) for mitigation of NO X from diesel engine exhaust is a laboratory proven technique with a good number of experimental studies. However, there are constraints which are preventing this technique to appear in practical applications. Prior prediction of exhaust characteristics with the NTP treatment according to the variations in its operating parameters can be a step ahead to make this technique applicable in real time. In this present study, experiments are conducted by varying parameters voltage, flow rate, temperature, discharge gap and initial sum of NO and NO 2 concentrations. Six hundred number of datasets are collected to train and test the predictive models which are made using multilayer perceptrons (MLP). The objective of these models is to predict the sum of NO and NO 2 concentrations at the downstream of the reactor during NTP based diesel exhaust treatment. As a part of the study, optimum number of neurons in the hidden layers is also found out. The root mean square error (RMSE) of an MLP with two hidden layers, each of 20 neurons, is found to be 3.29 ppm. Results assure that the prediction of sum of NO and NO 2 concentrations can be achieved with a good accuracy using MLP. [ABSTRACT FROM AUTHOR]

Mn/SAPO-34, Cu/SAPO-34, and Cu-Mn/SAPO-34 were prepared through ion-exchanged method and used to remove NO x from diesel engine exhausts. The original crystal and physical structure of SAPO-34 is maintained in the catalysts. The ion-exchanged amount of Cu in Cu–Mn/SAPO-34 is higher than that in Cu/SAPO-34, and more Cu + is formed as active center for low-temperature selective catalytic reduction (SCR). After co-doping of Cu and Mn, the acidic strength of the catalyst increases and formation of NH 3 NO x surface intermediate species is promoted. Cu–Mn/SAPO-34 exhibits high deNO x activity, hydrothermal stability, and resistance to hydrocarbon (HC). [ABSTRACT FROM AUTHOR]

Etheno-DNA adducts are biomarkers for assessing oxidative stress. In this study, the aim was to detect the level of etheno-DNA adducts and explore the relationship between the etheno-DNA adducts and genotoxicity biomarkers of the diesel engine exhaust (DEE)-exposed workers. We recruited 86 diesel engine testing workers with long-term exposure to DEE and 99 non-DEE-exposed workers. The urinary mono-hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) and etheno-DNA adducts (εdA and εdC) were detected by HPLC–MS/MS and UPLC–MS/MS, respectively. Genotoxicity biomarkers were also evaluated by comet assay and cytokinesis-block micronucleus assay. The results showed that urinary εdA was significantly higher in the DEE-exposed workers ( p < 0.001), exhibited 2.1-fold increase compared with the non-DEE-exposed workers. The levels of urinary OH-PAHs were positively correlated with the level of εdA among all the study subjects ( p < 0.001). Moreover, we found that the increasing level of εdA was significantly associated with the increased olive tail moment, percentage of tail DNA, or frequency of micronucleus in the study subjects ( p < 0.01). No significant association was observed between the εdC level and any measured genotoxicity biomarkers. In summary, εdA could serve as an indicator for DEE exposure in the human population. [ABSTRACT FROM AUTHOR]

The promotional mechanism of Nb addition on the activity and hydrothermal stability of CeZr 2 O x catalyst for the selective catalytic reduction of NO x with NH 3 (NH 3 -SCR) was investigated by various methods including N 2 -physisorption, XRD, H 2 -TPR and in situ DRIFTS. The Nb-promoted CeZr 2 O x catalyst showed remarkable NH 3 -SCR activity together with excellent N 2 selectivity, SO 2 /H 2 O resistance and outstanding hydrothermal stability. The characterization results showed that the introduction of Nb to CeZr 2 O x not only resulted in the high surface area and strong redox ability, but also promoted the adsorption and activation of NH 3 and enhanced the reactivity of adsorbed nitrate together with NH 3 species. All the above features were favorable for the superior NH 3 -SCR performance. In addition, the CeNb 3.0 Zr 2 O x catalysts hydrothermally aged below 800 °C still possessed high redox ability and abundant acid sites, all of which were responsible for the excellent hydrothermal durability. The novel CeNb 3.0 Zr 2 O x catalyst was a promising candidate for the removal of NO x from diesel engine. [ABSTRACT FROM AUTHOR]

We investigated whether exposure to carcinogenic diesel engine exhaust (DEE) was associated with altered adduct levels in human serum albumin (HSA) residues. Nano-liquid chromatography-high resolution mass spectrometry (nLC-HRMS) was used to measure adducts of Cys34 and Lys525 residues in plasma samples from 54 diesel engine factory workers and 55 unexposed controls. An untargeted adductomics and bioinformatics pipeline was used to find signatures of Cys34/Lys525 adductome modifications. To identify adducts that were altered between DEE-exposed and unexposed participants, we used an ensemble feature selection approach that ranks and combines findings from linear regression and penalized logistic regression, then aggregates the important findings with those determined by random forest. We detected 40 Cys34 and 9 Lys525 adducts. Among these findings, we found evidence that 6 Cys34 adducts were altered between DEE-exposed and unexposed participants (i.e., 841.75, 851.76, 856.10, 860.77, 870.43, and 913.45). These adducts were biologically related to antioxidant activity. • Cys34/Lys525 adducts reflect long-lasting effects of reactive oxygen/electrophilic species. • Investigated Cys34/Lys525 adductome alterations among diesel engine exhaust exposed workers. • Six Cys34 adducts were altered between exposed and unexposed participants. • Reactive oxygen/electrophilic species are involved in carcinogenicity of diesel exhaust. [ABSTRACT FROM AUTHOR]

The sulfur dioxide (SO 2 ) contained in combustion exhaust gases from medium-scale facilities or ocean ships must be removed because of its role as an air pollutant. In this study, dry DeSO x filter of manganese oxide was used to capture SO 2 with a simple sulfate reaction. The thermogravimetry (TG), experiments shows that the MnO 2 sample having a specific surface area of 250 m 2 /g absorbed SO 2 at about 0.45 g- SO2 /g- MnO2 and 0.18 g SO2 /g MnO2 at 450 °C and 250 °C, respectively. Desulfurization breakthrough experiment in a packed bed was employed to evaluate the possibility of deep desulfurization. As a result, the inlet SO 2 is almost absorbed by the high specific surface area (HSSA) MnO 2 bed, over 99.5% absorbed at space velocity of 0.5 × 10 4 h −1 . Higher space velocity condition is targeting a more compact filter. Under the condition of 5.0 × 10 4 h −1 , SO 2 over 80% against inlet SO 2 can be absorbed at early time. Conclusively, this material has a large enough SO 2 absorption rate to capture significant amounts of SO 2 gas. [ABSTRACT FROM AUTHOR]

The aim of this work is to utilize the heat energy wasted in exhaust gas of an internal combustion engine of low capacity for desalination using a submerged horizontal tube straight pass evaporator and a condensing unit, without the aid of any external energy used for pumping system. In this work a horizontal tube straight pass evaporator and water cooled condenser for condensing the evaporated steam were designed and fabricated. The experiments were conducted in a 5 hp diesel engine to analyze the performance of the submerged horizontal tube straight pass evaporator (SHTE) under various load conditions. It is evident that 3.0 l/h of saline water can be desalinated from the engine exhaust gas, without affecting the performance of the engine. More over nearly 24 l of water is heated, up to 60 °C in the condenser unit. By utilizing the heat energy in condenser water in addition to waste exhaust gas heat energy the overall efficiency of the system is enhanced and thermal pollution is also reduced considerably. [ABSTRACT FROM AUTHOR]

Highlights: [•] Increasing FIP and advancing SOI can improve combustion. [•] Soot and AM emissions decrease with increasing FIP and advancing SOI. [•] The application of EGR increases soot and AM emissions. [•] Soot-EC emission increases with the application of EGR at high load. [ABSTRACT FROM AUTHOR]

Highlights: [•] Exposure to DEPs induced higher oxidative stress in HBMVEC cells. [•] DEPs induce cell death and disrupt the function and integrity of HBMVEC cells. [•] Data indicate a potential role of DEPs in neurotoxicities. [Copyright &y& Elsevier]

Abstract: This study investigated the effect of adding a NO x adsorption layer to the cathode of an electrochemical cell on the removal of NO x from gaseous mixtures. The cathode was a composite of (La0.85Sr0.15)0.99MnO3 (LSM15) and Ce0.9Gd0.1O1.95 (CGO10). Two different kinds of adsorption layers, K–Pt–Al2O3 layer and Ba–Pt–Al2O3 layer (known as NO x storage/reduction (NSR) catalyst), were studied. The effects of the NSR adsorption layers on the electrode processes were characterized by electrochemical impedance spectroscopy (EIS). Both adsorption layers increased the reduction of NO x to N2 in an atmosphere that contained only NO. When O2 was present with NO in the atmosphere, the K–Pt–Al2O3 adsorption layer significantly enhanced the conversion of NO x to N2, but the Ba–Pt–Al2O3 adsorption layer had no effect. The selective removal of NO x under O2-rich conditions was achieved by modifying the LSM15/CGO10 cell with a suitable NSR adsorption layer. The improvement for NO x reduction by the adsorption layers was mainly contributed by the promotion of the adsorption and surface diffusion of NO x species at/near the triple phase boundary (TPB) regions of the electrode and probably the formation of a short and effective reaction path for NO x reduction. A stronger capability for oxidizing NO and/or trapping NO x under the test conditions may have contributed to the superior performance of the K–Pt–Al2O3 adsorption layer relative to the Ba–Pt–Al2O3 layer. [Copyright &y& Elsevier]

Abstract: This paper addresses the design of a novel laboratory bench for the practical evaluation of diesel oxidation catalysts (DOC) coated onto porous sintered metal filters (SMF). Such catalytic systems combine oxidation and filtration functionality in one process stage to remove hydrocarbons, carbon monoxide and soot from the exhaust of diesel engines. A unique feature of the bench is the reactor unit in which the used DOC-SMF disc (diameter: 30mm) is reliably sealed by a special configuration of metal rings. The designing of the reactor was supported by computational fluid dynamics showing that the temperature profile at the metal substrate is almost isothermal under typical test conditions. The suitability of the laboratory reactor was demonstrated by practical evaluation of a DOC-SMF sheet providing plausible performance upon oxidation of propene, carbon monoxide and nitric oxide. Furthermore, it was shown that the catalytic efficiency of the DOC-SMF disc was not affected by pore and film diffusion, respectively. [Copyright &y& Elsevier]

Abstract: A Ce-Ti based (CeO2-TiO2) catalyst prepared by an optimized homogeneous precipitation method showed excellent NH3-SCR activity, high N2 selectivity, broad operation temperature window, and high resistance to space velocity (even under a high gas hourly space velocity (GHSV) of 500,000h−1). Compared with V2O5-WO3/TiO2 and Fe-ZSM-5 catalysts, the CeO2-TiO2 catalyst showed better catalytic performance for NH3-SCR. Under a more realistic condition of simulated diesel engine exhaust, the monolith catalyst of CeO2-TiO2 showed over 90% NO x conversion from 250 to 450°C under a GHSV of 20,000h−1 in the presence of H2O, CO2, and C3H6. The high dispersion of active CeO2 on TiO2 in the process of homogenous precipitation and the synergistic effects between CeO2 and TiO2 in CeO2-TiO2 are important reasons for the high NH3-SCR activity. [Copyright &y& Elsevier]

Abstract: A superior Ce-W-Ti mixed oxide catalyst prepared by a facile homogeneous precipitation method showed excellent NH3-SCR activity and 100% N2 selectivity with broad operation temperature window and extremely high resistance to space velocity, which is a very promising catalyst for NO x abatement from diesel engine exhaust. The excellent catalytic performance is associated with the highly dispersed active Ce and promotive W species on TiO2. The introduction of W species could increase the amount of active sites, oxygen vacancies, and Brønsted and Lewis acid sites over the catalyst, which is also beneficial to improve the low temperature activity by facilitating “fast SCR” reaction and enhance both of the high temperature activity and N2 selectivity simultaneously by inhibiting the unselective oxidation of NH3 at high temperatures. [Copyright &y& Elsevier]

Abstract: Diesel engine exhaust contains large numbers of submicrometer particles that degrade air quality and human health. This study examines the number emission characteristics of 10–1000nm nonvolatile particles from a heavy-duty diesel engine, operating with various waste cooking oil biodiesel blends (B2, B10 and B20), engine loads (0%, 25%, 50% and 75%) and a diesel oxidation catalyst plus diesel particulate filter (DOC+DPF) under steady modes. For a given load, the total particle number concentrations (N TOT) decrease slightly, while the mode diameters show negligible changes with increasing biodiesel blends. For a given biodiesel blend, both the N TOT and mode diameters increase modestly with increasing load of above 25%. The N TOT at idle are highest and their size distributions are strongly affected by condensation and possible nucleation of semivolatile materials. Nonvolatile cores of diameters less than 16nm are only observed at idle mode. The DOC+DPF shows remarkable filtration efficiency for both the core and soot particles, irrespective of the biodiesel blend and engine load under study. The N TOT post the DOC+DPF are comparable to typical ambient levels of ∼104 cm−3. This implies that, without concurrent reductions of semivolatile materials, the formation of semivolatile nucleation mode particles post the aftertreatment is highly favored. [Copyright &y& Elsevier]

Abstract: Exhaust emissions from a diesel vehicle were studied using FTIR, SMCA-REMPI, and SMPS. With these techniques, quantitative emission properties of NO, NO2, N2O, NH3, CO, CH4, C2H4, C3H6, HCHO, toluene, toluene+CH2, toluene+2CH2, β-methylstyrene, naphthalene, 2-methylnaphthalene, phenanthrene, and o-cresol, as well as particle size distributions, were obtained in constant-speed operation at 0–80km/h, which corresponds to a brake mean effective pressure (BMEP) of 0–293kPa. NO emission increased as the in-cylinder temperature increased, corresponding to increased engine load. NO2 and N2O had a strong correlation to equivalence ratio. The emission characteristics of non-aromatic hydrocarbons depended on engine load. At low load, the emissions were high because low in-cylinder temperature and Exhaust Gas Recycling (EGR) prevented complete fuel oxidation. Equivalence ratio had a slight influence on the non-aromatic hydrocarbon emissions. The profiles of aromatic hydrocarbon exhibited two shapes. One was a toluene group and another was a styrene and naphthalene group. The shapes of the toluene group were similar to those of non-aromatic hydrocarbons. On the other hand, the styrene and naphthalene group emissions at idling were low, suggesting that they were not formed at low load. These features concerning the two groups of aromatic hydrocarbons were also observed in a transient driving cycle. Emission of accumulation mode particles was correlated with equivalence ratio. Higher emissions were observed when the equivalence ratio was higher, and the particle diameters also increased. Emission of nucleation mode particles increased as the engine load increased, because the amount of injected fuel per cycle increased. [ABSTRACT FROM AUTHOR]

Abstract: The exhaust gas from an internal combustion engine carries away about 30% of the heat of combustion. The energy available in the exit stream of many energy conversion devices goes as waste, if not utilized properly. The major technical constraint that prevents successful implementation of waste heat recovery is due to its intermittent and time mismatched demand and availability of energy. In the present work, a shell and finned tube heat exchanger integrated with an IC engine setup to extract heat from the exhaust gas and a thermal energy storage tank used to store the excess energy available is investigated in detail. A combined sensible and latent heat storage system is designed, fabricated and tested for thermal energy storage using cylindrical phase change material (PCM) capsules. The performance of the engine with and without heat exchanger is evaluated. It is found that nearly 10–15% of fuel power is stored as heat in the combined storage system, which is available at reasonably higher temperature for suitable application. The performance parameters pertaining to the heat exchanger and the storage tank such as amount of heat recovered, heat lost, charging rate, charging efficiency and percentage energy saved are evaluated and reported in this paper. [ABSTRACT FROM AUTHOR]

Abstract: The effect of increasing primary amine hydrocarbon chain length on the SCR of NO x from diesel engine exhaust was investigated and compared to ammonia. Methylamine (CH3NH2), ethylamine (CH3CH2NH2), propylamine (CH3CH2CH2NH2) and butylamine (CH3CH2CH2CH2NH2) were tested using a 12 cell mini core NH3 – SCR catalyst cut from a 400cpsi block. There is a steady decrease in NO x conversion as the length of the hydrocarbon chain increases (from 50% for methylamine to 26% for butylamine). For the same number of carbons in the amine, primary amines are more active reductants than methyl substituted secondary or tertiary amines. For example, ethylamine (NO x conversion of 45%) is more active than dimethylamine (NO x conversion of 34%). Since the amines are reactive in the gas phase in the temperature range of diesel engine exhaust, gas phase conversions were estimated by replacing the mini core SCR catalyst with an equivalent length of quartz beads. There was no smooth transition in gas phase NO and NO x conversions with increasing hydrocarbon chain length. The results suggest a different mechanism for gas phase reactions depending on the nature of the amine. [Copyright &y& Elsevier]

Abstract: Resistive electrochemical sensors based on vanadium oxides equipped with a pair of interdigital Au electrodes can detect NH3 gas selectively at high temperature (500°C). NH3 addition in a base gas increased the relative conductance (σ/σ 0). Addition of less electronegative cation (Ce, Zr, Mg) to V2O5 increased the response and recovery rates, while electronegative cation (Al, Fe, Ni) increased sensor response magnitude. Among the samples tested, Al and Ce co-doped sample (VAlCe) was the most suitable sensor. The VAlCe sensor responded rapidly and linearly to change in concentration of NH3 in the oxygen rich gas mixture and showed high selectivity in the presence of coexisting gases (NO, CO, H2). The presence of water vapor did not markedly decrease the response magnitude but increased the response rate; the 90% response and 50% recovery times were less than 15s. Based on the in situ UV–vis results, a possible sensing mechanism is proposed; adsorbed NH3 causes reduction of V5+ to V4+, which results in the conductivity increase. Role of surface acidity on the selective detection of NH3 as a basic molecule is also discussed. [Copyright &y& Elsevier]

Overnight aging experiments with diesel engine exhaust from a diesel power aggregate, with no or 9kW load, and from a diesel-fueled vehicle were conducted in an environmental chamber. During a 24h aging period the volatilities of monodisperse particles at 140, 250 and 360°C heater temperatures were analyzed with volatility tandem differential mobility analysis (VTDMA). The particulate organic to total carbon ratio and organic carbon subfractions at 120, 250, 450 and 550°C were analyzed with thermal-optical carbon analysis for samples from fresh, 8 or 18h aged and 24h aged aerosol. During the experiment also the particle size distribution, ozone and nitrogen oxide concentration, and temperature, relative humidity and total solar and total ultraviolet radiation in the chamber were monitored. After injection, the geometric mean diameter and number concentration of the particles in the chamber were 66–85nm and 0.9–4.6×105 cm−3, respectively. The particles were seen to grow fast, at a growth rate of 18–47nmh−1 during the first hour. The fresh particles from the diesel power aggregate contained 37–45% of apparent volume semi-volatile compounds with no load and 10–24% with 9kW load. The semi-volatile apparent volume fraction at 360°C for 50nm particles produced by the diesel power aggregate was 57%. After 24h of aging, the semi-volatile apparent volume fraction at 360°C for 100nm particles was 99%. This suggests that the particles in the 24h aged aerosol at this size class are no more primary particles but particles that are formed in the chamber through nucleation and subsequent growth. [Copyright &y& Elsevier]

The selective catalytic reduction (SCR) of NOx by C2H5OH was studied in excess oxygen over Ag/Al2O3 catalysts with different Ag loadings at lab conditions. The 4% Ag/Al2O3 has the highest activity for the C2H5OH-SCR of NOx with a drawback of simultaneously producing CO and unburned THC in effluent gases. An oxidation catalyst 10% Cu/Al2O3 was directly placed after the Ag/Al2O3 to remove CO and unburned THC. Washcoated honeycomb catalysts were prepared based on the 4% Ag/Al2O3 and 10% Cu/Al2O3 powders and tested for the C2H5OH-SCR of NOx on a diesel engine at the practical operating conditions. Compared with the Ag/Al2O3 powder, the Ag/Al2O3 washcoated honeycomb catalyst (SCR catalyst) has a similar activity for NOx reduction by C2H5OH and the drawback of increasing the CO and unburned THC emissions. Using the SCR+Oxi composite catalyst with the optimization of C2H5OH addition, the diesel engine completely meets EURO III emission standards. [Copyright &y& Elsevier]

Abstract: The “Cincinnati Childhood Allergy and Air Pollution Study (CCAAPS)” is underway to determine if infants who are exposed to diesel engine exhaust particles are at an increased risk for atopy and atopic respiratory disorders, and to determine if this effect is magnified in a genetically at risk population. In support of this study, a methodology has been developed to allocate local traffic source contributions to ambient PM2.5 in the Cincinnati airshed. As a first step towards this allocation, UNMIX was used to generate factors for ambient PM2.5 at two sites near at interstate highway. Procedures adopted to collect, analyze and prepare the data sets to run UNMIX are described. The factors attributed to traffic sources were similar for the two sites. These factors were also similar to locally measured truck engine-exhaust enriched ambient profiles. The temporal variation of the factors was analyzed with clear differences observed between factors attributed to traffic sources and combustion-related regional secondary sources. [Copyright &y& Elsevier]

A catalytic trap for soot particles was prepared by deposition of Cu–V–K–Cl catalyst on a ceramic foam. Catalytic trap performances were evaluated by treating the exhaust of a gas oil burner under different operating conditions. The results obtained showed that ceramic foam is a particularly suitable support for this application since it yields low gas pressure drop, good soot collection efficiency (“deep bed” filtration mechanism), high thermal shock resistance and good contact throughout the filter between soot particles and catalyst surface. In addition, the catalytic foam trap is able to spontaneously regenerate at operating conditions comparable to those typical of diesel engine exhaust and after more than 70 test hours it retains its activity towards soot oxidation. [Copyright &y& Elsevier]

A CeWO x catalyst was washcoated on cylindrical cordierite honeycomb for the tests under practical conditions. The catalyst exhibited outstanding NH 3 -SCR performance. A European steady-state cycle (ESC) test showed that the NH 3 -SCR system based on the CeWO x catalyst could make the NO x emission from diesel engine completely meet the Euro V limit without the help of any other after-treatment device. [ABSTRACT FROM AUTHOR]

Previous studies have reported that miners (and other workers) exposed to high levels of diesel engine exhaust (DEE) have an increased risk of lung function decline. The main objective of this study was to evaluate associations between exposure to different components associated with DEE in relation to lung function across a 12-h working shift. Eighty underground gold miners and twenty surface miners completed spirometry and questionnaires at the beginning and end of their 12 h work shift. Personal exposure to elemental carbon (EC), volatile organic compounds (VOCs), nitrogen dioxide (NO2), particle size and particle number were monitored during their shift. Multiple regression models were used to examine the associations between DEE and lung function, adjusting for a range of covariates. Underground miners were exposed to higher levels of EC, VOCs, NO2, and particle number and larger mean particle size than surface miners. Cross-shift reduction in Z-score value of FEV1/FVC in underground miners was statistically significantly greater than those of surface miners. The cross-shift change in Z-score value of FEV1/FVC was associated with exposure to higher concentration of EC and particle number, but not with VOCs, NO2 and particle size. Occupational exposure to diesel engine exhaust in current Australian gold mines is substantial. Exposures were higher in underground miners and had a negative association with their lung function over a single 12-h shift. [ABSTRACT FROM AUTHOR]

• Occupational diesel engine exhaust (DEE) exposure alters nasal gene expression. • DEE-associated genes have an exposure-response relationship with elemental carbon levels. • DEE and cigarette smoke (CS) exposures up-regulate common genes. • DEE and CS exposure have a synergistic effect on gene expression. Diesel engine exhaust (DEE) exposure causes lung cancer, but the molecular mechanisms by which this occurs are not well understood. To assess transcriptomic alterations in nasal epithelium of DEE-exposed factory workers to better understand the cellular and molecular effects of DEE. Nasal epithelial brushings were obtained from 41 diesel engine factory workers exposed to relatively high levels of DEE (17.2–105.4 μg/m3), and 38 unexposed workers from factories without DEE exposure. mRNA was profiled for gene expression using Affymetrix microarrays. Linear modeling was used to identify differentially expressed genes associated with DEE exposure and interaction effects with current smoking status. Pathway enrichment among differentially expressed genes was assessed using EnrichR. Gene Set Enrichment Analysis (GSEA) was used to compare gene expression patterns between datasets. 225 genes had expression associated with DEE exposure after adjusting for smoking status (FDR q < 0.25) and were enriched for genes in pathways related to oxidative stress response, cell cycle pathways such as MAPK/ERK, protein modification, and transmembrane transport. Genes up-regulated in DEE-exposed individuals were enriched among the genes most up-regulated by cigarette smoking in a previously reported bronchial airway smoking dataset. We also found that the DEE signature was enriched among the genes most altered in two previous studies of the effects of acute DEE on PBMC gene expression. An exposure-response relationship was demonstrated between air levels of elemental carbon and the first principal component of the DEE signature. A gene expression signature was identified for workers occupationally exposed to DEE that was altered in an exposure-dependent manner and had some overlap with the effects of smoking and the effects of acute DEE exposure. This is the first study of gene expression in nasal epithelial cells of workers heavily exposed to DEE and provides new insights into the molecular alterations that occur with DEE exposure. [ABSTRACT FROM AUTHOR]