A study aiming to measure ammonia emissions from light duty vehicles has been performed in the Vehicle Emission Laboratory at the European Commission Joint Research Centre, Ispra, Italy. Ammonia, ...known for being toxic and dangerous for the environment, also contributes to the formation of particulate matter that has been related with adverse health and environmental effects.
Nine modern light duty vehicles tested over the New European Driving Cycle showed that ammonia emissions are considerable for gasoline and ethanol flexi-fuel vehicles and also for one diesel vehicle equipped with a selective catalytic reduction system, ranging from 4 mg/km to 70 mg/km. Real-time ammonia emission profiles were monitored at the tailpipe by a High Resolution Fourier Transform Infrared spectrometer during tests at 22 and/or −7 °C. Ammonia emissions are thoroughly discussed and compared to those of its precursors, CO and NO, and other regulated compounds.
•All studied vehicles emitted NH3 when tested over the NEDC at 22 and −7 °C.•NH3 emissions from Euro 5–6 vehicles are similar to those reported a decade ago.•Vehicular emissions of NH3 and CO presented good correlation.•Emission of NH3 depends on ambient temperature and NOx emission control.
The number of registrations of light duty hybrid electric vehicles has systematically increased over the last years and it is expected to keep growing. Hence, evaluation of their emissions becomes ...very important in order to be able to anticipate their impact and share in the total emissions from the transport sector. For that reason the emissions from a Euro 5 compliant hybrid electric vehicle (HV2) and a Euro 5 plug-in hybrid electric vehicle (PHV1) were investigated with special interest on exhaust emissions of ammonia, acetaldehyde and ethanol. Vehicles were tested over the World harmonized Light-duty Test Cycle (WLTC) at 23 and −7 °C using two different commercial fuels E5 and E10 (gasoline containing 5% and 10% vol/vol of ethanol, respectively). PHV1 resulted in lower emissions than HV2 due to the pure electric strategy used by the former. PHV1 and HV2 showed lower regulated emissions than conventional Euro 5 gasoline light duty vehicles. However, emissions of ammonia (2–8 and 6–15 mg km−1 at 22 and −7 °C, respectively), ethanol (0.3–0.8 and 2.6–7.2 mg km−1 at 22 and −7 °C, respectively) and acetaldehyde (∼0.2 and 0.8–2.7 mg km−1 at 22 and −7 °C, respectively) were in the same range of those recently reported for conventional gasoline light duty vehicles.
•NH3, ethanol and acetaldehyde emissions are in the same range of gasoline vehicles.•Regulated emissions are in the same range as gasoline vehicles.•Higher regulated and unregulated emissions were observed at −7 °C than at 23 °C.•The battery state of charge strongly impacts the plug-in hybrid emissions.
•Hydrous and anhydrous ethanol blends show similar regulated and unregulated emissions.•Low temperature leads to higher emissions for all tested blends.•E85 and E75 blends resulted in higher ...emissions of acetaldehyde and ethanol.•Higher emissions of acetaldehyde and ethanol yield higher OFP.
Regulated and unregulated emissions from a Euro 5a flex-fuel vehicle tested with nine different hydrous and anhydrous ethanol containing fuel blends at 23 and −7°C over the World harmonized Light-duty vehicle Test Cycle and the New European Driving Cycle, were investigated at the Vehicle Emission Laboratory at the European Commission Joint Research Centre Ispra, Italy. The experimental results showed no differences on the regulated and unregulated emissions when hydrous ethanol blends were used instead of anhydrous ethanol blends. The use of E85 and E75 blends (gasoline containing 85% and 75% of ethanol, respectively) resulted in a reduction of NOx emissions (30–55%) but increased the emissions of carbon monoxide, methane, carbonyls and ethanol compared to E5, E10 and E15 blends (gasoline containing 5%, 10% and 15% of ethanol, respectively). The increase of the acetaldehyde and ethanol emissions (up to 120% and 350% at 23°C and up to 400% and 390% at −7°C, for acetaldehyde and ethanol, respectively) caused a severe increment of the ozone formation potential. Most of the studied pollutants presented similar emission factors during the tests performed with E10 and E15 blends. The emission factors of most unregulated compounds were lower over the NEDC (with ammonia as an exception) than over the WLTC. However, when taking into consideration only the cold start emissions, emission factors over the WLTC were observed to be higher, or similar, to those obtained over the NEDC. Low ambient temperature caused an increase of the emissions of all studied compounds with all tested blends.
Vehicles are considered to be an important source of ammonia (NH3) and isocyanic acid (HNCO). HNCO and NH3 have been shown to be toxic compounds. Moreover, NH3 is also a precursor in the formation of ...atmospheric secondary aerosols. For that reason, real-time vehicular emissions from a series of Euro 5 and Euro 6 light-duty vehicles, including spark ignition (gasoline and flex-fuel), compression ignition (diesel) and a plug-in electric hybrid, were investigated at 23 and −7°C over the new World harmonized Light-duty vehicle Test Cycle (WLTC) in the Vehicle Emission Laboratory at the European Commission Joint Research Centre Ispra, Italy. The median HNCO emissions obtained for the studied fleet over the WLTC were 1.4mgkm−1 at 23°C and 6mgkm−1 at −7°C. The fleet median NH3 emission factors were 10mgkm−1 and 21mgkm−1 at 23 and −7°C, respectively. The obtained results show that even though three-way catalyst (TWC), selective catalytic reduction (SCR), and NOx storage catalyst (NSC) are effective systems to reduce NOx vehicular emissions, they also lead to considerable emissions of the byproducts NH3 and/or HNCO. It is also shown that diesel light-duty vehicles equipped with SCR can present NH3 emission factors as high as gasoline light-duty vehicles at both, 23 and −7°C over the WLTC. Therefore, with the introduction in the market of this DeNOx technology, vehicular NH3 emissions will increase further.
•cBM-MSCs and cAd-MSCs present similar immunophenotype, multilineage differentiation and immunomodulatory capacity.•Differences in proliferation and secretory profile are observed between both ...tissues.•Secretome from cBM-MSCs contains the highest concentration of soluble factors and exosomes.•Proteomic analysis reveals different exosomal cargo in each source related to regulation and metabolic processes.
The two main sources of mesenchymal stem cell (MSCs) in the canine species are bone marrow (cBM-MSCs) and adipose tissue (cAd-MSCs). The secretion of multitude bioactive molecules, included under the concept of secretome and found in the cultured medium, play a predominant role in the mechanism of action of these cells on tissue regeneration. Although certain features of its characterization are well documented, their secretory profiles remain unknown. We described and compared, for the first time, the secretory profile and exosomes characterization in standard monolayer culture of MSCs from both sources of the same donor as well as its immunomodulatory potential. We found that despite the similarity in surface immunophenotyping and trilineage differentiation, there are several differences in terms of proliferation rate and secretory profile. cAd-MSCs have advantages in proliferative capacity, whereas cBM-MSCs showed a significantly higher secretory production of some soluble factors (IL-10, IL-2, IL-6, IL-8, IL-12p40, IFN-γ, VEGF-A, NGF-β, TGF-β, NO and PGE2) and exosomes under the same standard culture conditions. Proteomics analysis confirm that cBM-MSCs exosomes have a greater number of characterized proteins involved in metabolic processes and in the regulation of biological processes compared to cAd-MSCs. On the other hand, secretome from both sources demonstrate similar immunomodulatory capacity when tested in mitogen stimulated lymphocyte reaction, but not in their exosomes at the dose used. Considering that the use of secretome open as a new therapeutic strategy for different diseases, without the need to implant cells, those biological differences should be considered, when choosing the MSCs source, for either cellular implantation or direct use of secretome for a specific clinical application.
Carbonaceous particulate matter (PM), comprising black carbon (BC), primary organic aerosol (POA) and secondary organic aerosol (SOA, from atmospheric aging of precursors), is a highly toxic vehicle ...exhaust component. Therefore, understanding vehicle pollution requires knowledge of both primary emissions, and how these emissions age in the atmosphere. We provide a systematic examination of carbonaceous PM emissions and parameterisation of SOA formation from modern diesel and gasoline cars at different temperatures (22, -7 °C) during controlled laboratory experiments. Carbonaceous PM emission and SOA formation is markedly higher from gasoline than diesel particle filter (DPF) and catalyst-equipped diesel cars, more so at -7 °C, contrasting with nitrogen oxides (NO
). Higher SOA formation from gasoline cars and primary emission reductions for diesels implies gasoline cars will increasingly dominate vehicular total carbonaceous PM, though older non-DPF-equipped diesels will continue to dominate the primary fraction for some time. Supported by state-of-the-art source apportionment of ambient fossil fuel derived PM, our results show that whether gasoline or diesel cars are more polluting depends on the pollutant in question, i.e. that diesel cars are not necessarily worse polluters than gasoline cars.
Fossil fuel-powered vehicles emit significant particulate matter, for example, black carbon and primary organic aerosol, and produce secondary organic aerosol. Here we quantify secondary organic ...aerosol production from two-stroke scooters. Cars and trucks, particularly diesel vehicles, are thought to be the main vehicular pollution sources. This needs re-thinking, as we show that elevated particulate matter levels can be a consequence of 'asymmetric pollution' from two-stroke scooters, vehicles that constitute a small fraction of the fleet, but can dominate urban vehicular pollution through organic aerosol and aromatic emission factors up to thousands of times higher than from other vehicle classes. Further, we demonstrate that oxidation processes producing secondary organic aerosol from vehicle exhaust also form potentially toxic 'reactive oxygen species'.
► Most of the pollutants studied were emitted during the cold start of the vehicle. ► More carbonyls were associated with oxygenated fuel (E85–E75) than with E5. ► Acetaldehyde emissions were found ...particularly enhanced at −7°C with E75. ► Elevated methane and ozone precursor emissions were measured at −7°C with E75. ► Ammonia and toluene emissions associated to E75–E85 were lower than with E5.
According to directives 2003/30/EC and 2009/28/EC of the European Parliament and the Council, Member States should promote the use of biofuel. Consequently, since 2011 all fuels on the market used for transport purpose must contain a fraction of 5.75% renewable energy sources. Ethanol in gasoline is a promising solution to reach this objective. In addition to decrease the dependence on fossil fuel, ethanol contributes to reducing air pollutant emissions during combustion (carbon monoxide and total hydrocarbons), and has a positive effect on greenhouse gas emissions. These considerations rely on numerous emission studies performed in standard conditions (20–30°C), however, very few emission data are available for cold ambient temperatures, as they prevail in winter times in e.g., Northern Europe. This paper presents a chassis dynamometer study examining the effect of ethanol (E75–E85) versus gasoline (E5) at standard and low ambient temperatures (22°C and −7°C, respectively). Emissions of modern passenger cars complying with the latest European standards (Euro4 and Euro5a) were recorded over the New European Driving Cycle (NEDC) and the Common Artemis Driving Cycle (CADC). Unregulated compounds such as methane, ammonia, and small chain hydrocarbons were monitored by an online Fourier Transformed Infra-Red spectrometer. In addition, a number of ozone precursors (carbonyls and volatile organic hydrocarbons) were collected and analyzed offline by liquid and gas chromatography in order to evaluate the ozone formation potential (OFP) of the exhaust. Results showed higher unregulated emissions at −7°C than at 22°C, regardless of the ethanol content in the fuel blend. More carbonyls were associated with oxygenated fuel, and acetaldehyde emissions were found particularly enhanced at −7°C with E75. In addition, elevated methane emission was measured at low ambient temperature when ethanol fuel was used. Moreover, the OFP of the exhaust gas at −7°C increased with the amount of ethanol in gasoline when the cold start excess emissions were included. However, regardless of the ambient temperature, the ammonia and toluene emissions associated to E75–E85 were lower than with E5.
•Derive an experimentally validated quasi-LPV model for control applications.•That model is enough to design a quasi-LPV observer to detect sensor faults.•A fault detection and isolation system is ...developed to detect sensor faults..
In this study, a sensor fault detection and isolation (FDI) system is presented for a boiler-turbine unit of a thermal power plant in Mexico. The FDI system is based on a Luenberger-like observer for residual generation. An adaptive threshold for residual evaluation is considered to avoid false alarms. The observer is based on a quasi-linear parameter variant (quasi-LPV) model of the boiler-turbine unit parameterized with real data of the plant in a wide range of operations, namely, at low, medium, and high loads. The quasi-LPV model adequately represents the dynamics of more critical variables including first stage turbine pressure, superheated steam pressure, drum pressure, and electric power. The performance of the FDI system is evaluated in a practical scenario by using real data from the thermoelectric plant. The main contribution of this study involves proposing a reliable fault diagnosis system to detect sensor faults in a wide operational range of the process based on the quasi-LPV framework.
This paper concerns the design of a generalized functional observer for Takagi–Sugeno descriptor systems. Furthermore, a generalized structure is herein introduced for purposes of estimating linear ...functions of the states of descriptor nonlinear systems represented into a Takagi–Sugeno descriptor form. The originality of the functional generalized observer structure is that it provides additional degrees of freedom in the observer design, which allows for improvements in the estimation against parametric uncertainties. The effectiveness of the developed design is illustrated by a nonlinear model of a single link robotic arm with a flexible link. A comparison between the functional generalized observer and the functional proportional observer is given to demonstrate the observer performances.
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