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We systematically study the explicit roles of noble metal catalysts in steering the gas selectivity of metal oxides toward specific target analytes by using highly dispersed catalysts on In2O3 nanofibers as a consistent synthetic platform.

The knowledge leveraged from adsorption property can be used to induce enhancements in the prediction of diffusion property within metal–organic frameworks.

Inverse materials design entails providing desired properties as inputs and obtaining fine-tuned materials that fit the given criteria as outputs. Although this workflow would in principle lead to significant efficiency in materials design, it is difficult in practice to successfully implement a robust, accurate inverse design platform. In this work, we used a validated platform which integrates a genetic algorithm with machine learning to design user-desired metal–organic frameworks (MOFs) with the xenon/krypton separation being presented as a case study. Using our platform, we obtained two record-breaking MOFs that show significant improvement over the current record. Moreover, with facile modification in the cost function, we demonstrate that our platform can generate MOFs that are finely tuned to the specific desires of users across multiple properties and a range of property values.

The emission characteristics of mobile air pollution sources belonging to the non-road sector have yet to be thoroughly investigated, especially when compared to those of on-road vehicles. Hence, the present study employed an engine dynamometer to evaluate the emissions of a diesel engine complying with Tier 3 standards during various driving modes (KC1-8, NRSC, and NRTC) and a portable emissions measurement system (PEMS) to assess those of two excavators, one complying with Tier 3 and the other with Tier 4 standards, during real-world working and driving conditions. The characteristics and chemical composition of the emitted regulated pollutants (carbon monoxide (CO), non-methane hydrocarbon (NMHC), nitrogen oxide (NOx), and particulate matter (PM)) and hazardous air pollutants (HAPs), e.g., volatile organic compounds (VOCs), aldehydes, and polycyclic aromatic hydrocarbons (PAHs), were then determined. For the regulated pollutants, NRTC mode generated the highest emissions owing to the rapid changes in engine load and speed during transitions. As a result of the after-treatment systems, which utilized a diesel oxidation catalyst (DOC) and selective catalytic reduction (SCR), CO, NMHC, and NOx emissions from the Tier 4-compliant excavator were lower than those from the Tier 3-compliant diesel engine and excavator. The operating conditions of the diesel engine and construction equipment as well as the after-treatment systems significantly affected the composition of the non-methane volatile organic compound (NMVOC) emissions, which were dominated by alkanes that comprised 23 detected species. Sampling the particle-phase PAHs, we found phenanthrene, fluoranthene, and naphthalene; furthermore, we estimated the concentrations of the gas-phase PAHs with models to obtain the total PAH concentrations. Formaldehyde, which contributed the largest fraction of the aldehydes, was more abundant than the other species. Thus, emissions from non-road sources, including construction equipment, must be controlled because of the considerable health risks from pollutants such as formaldehyde and benzene. Our results will aid in the establishment of a national emission inventory for HAPs.

Gasoline direct injection (GDI) engines emit less carbon dioxide (CO2) than port fuel injection (PFI) engines when fossil fuel conditions are the same. However, GDI engines emit more ultrafine particulate matter, which can have negative health effects, leading to particulate emission regulations. To satisfy these regulations, various studies have been done to reduce particulate matter, and several studies focused on lubricants. This study focuses on the influence of lubricant on the formation of particulate matter and its effect on particulate emissions in GDI engines. An instrumented, combustion and optical singe-cylinder GDI engine fueled by four different lubricant-gasoline blends was used with various injection conditions. Combustion experiments were used to determine combustion characteristics, and gaseous emissions indicated that the lubricant did not influence mixture homogeneity but had an impact on unburned fuels. Optical experiments showed that the lubricant did not influence spray but did influence wall film formation during the injection period, which is a major factor affecting particulate matter generation. Particulate emissions indicated that lubricant included in the wall film significantly affected PN emissions depending on injection conditions. Additionally, the wall film influenced by the lubricant affected the overall particle size and its distribution.

Hydroelectric nanogenerators have been previously proposed to recycle various water resources and polluted water. However, as conventional hydroelectric nanogenerators only utilize water resources, they cannot provide a fundamental solution for water recycling. In this study, a water purification membrane is proposed that can simultaneously generate electricity during the purification process (electricity generation and purification membrane (EPM)) for water recycling. As polluted water passes through the EPM, the water is purified in the perpendicular direction, while electricity is simultaneously produced in the horizontal direction by the movement of ions. Notably, the EPM exhibits high energy generation performance (maximum power 16.44 µW and energy 15.16 mJ) by the streaming effect of water-streaming carbon nanotubes (CNTs). Moreover, by using a poly(acrylic acid)/carboxymethyl cellulose (PAA/CMC) binder to EPM, the energy-generation performance and long-term stability are substantially improved and outstanding mechanical stability is provided, regardless of the acidity of the water source (pH 1-10). More importantly, the EPM exhibits the water purification characteristics of90% rejection of sub-10 nm pollutants and potentiality of ångstrom level cation rejection, with simultaneous and continuous energy generation. Overall, this study proposes an efficient EPM model, which can be potentially used as a next-generation renewable energy generation approach, thus laying the foundation for effective utilization of polluted water resources.

Tires generally wear out due to the friction between the tire and the road surface. Minimizing tire wear could reduce the non-exhaust particulate matter (PM) emissions from tires. Typically, tire treadwear grade can be used as an indicator of PM emissions from tires. Tires that wear out quickly will produce higher PM emissions than more durable tires. In this study, the effect of treadwear grade on the generation of tire PM emissions was investigated through laboratory and on-road driving measurements. In the laboratory measurements, a tire wear simulator installed in an enclosed chamber was used to eliminate artifacts caused by interfering particles during the generation and measurement of tire wear particles. For realistic on-road driving measurements, a mobile sampling vehicle was employed to sample road dust. The road dust was chemically analyzed using pyrolysis gas chromatography-mass spectrometry (GC-MS) to characterize the tire-road wear particles. Both measurements showed that the higher treadwear grade generated lower tire PM emissions due to the high strength of the rubber, except for the UTQG 700 tire. The UTQG 700 tire, which had the highest treadwear grade, produced higher PM emissions than the UTQG 350 and 500 tires because it readily formed the fine particles due to lamellar peeling rather than tearing or curling of tire treads. Notably, tire nanoparticles were observed in laboratory measurements due to the volatilization and nucleation of the sulphur (S) and zinc (Zn) compounds in the tire tread due to the frictional heat between the tire and paved road surface.

With global anthropogenic black carbon (BC) emissions increasing, automobiles are significantly contributing as the major source of emissions. However, the appropriate regulations of BC emissions from vehicles are not in place. This study examined BC emissions following fuel types (gasoline, liquefied petroleum gas (LPG), and diesel) and engine combustion (gasoline direct injection (GDI) and multi-port injection (MPI) for gasoline vehicles) with emission regulations. To this end, chassis dynamometer and aethalometer (AE33) were used. Driving modes created by the National Institute of Environmental Research (NIER) and emission certification modes (CVS-75 and NEDC) for vehicles in Korea were used to determine BC emissions for various vehicle speeds. In addition, the contributions of biomass and coal combustion to the data of AE33 were analyzed to determine the possibility of tracking the BC sources. MPI, LPG, and EURO 6 with diesel particulate filter (DPF) vehicles emitted the lowest BC emissions in NIER modes. Among gasoline vehicles, MPI vehicles showed the lower BC content in PM emissions. Also, older vehicles in MPI vehicles emitted the high PM and BC emissions. The BC emissions of EURO 3 vehicles without DPF were the highest as the results of previous studies, and it was found that as emissions regulations were tightened, the level of BC results of diesel vehicles became similar with MPI vehicles. The average absorption &Aring, ngstr&ouml, m exponent (AAE) from difference emissions sources were biomass combustion (oak wood) &gt, coal combustion (the power plant stack) &gt, automobile emissions (gasoline, LPG, diesel).

The characteristics of primary gas/aerosol and secondary aerosol emissions were identified for small passenger vehicles using typical fuel types in South Korea (gasoline, liquefied petroleum gas (LPG), and diesel). The generation of secondary organic aerosol (SOA) was explored using the potential aerosol mass (PAM) oxidation flow reactor. The primary emissions did not vary significantly between fuel types, combustion technologies, or aftertreatment systems, while the amount of NH3 was higher in gasoline and LPG vehicle emissions than that in diesel vehicle emissions. The SOA emission factor was 11.7–66 mg kg-fuel−1 for gasoline vehicles, 2.4–50 mg kg-fuel−1 for non-diesel particulate filter (non-DPF) diesel vehicles (EURO 2–3), 0.4–40 mg kg-fuel−1 for DPF diesel vehicles (EURO 4–6), and 3–11 mg kg-fuel−1 for LPG vehicles (lowest). The carbonaceous aerosols (equivalent black carbon (eBC) + primary organic aerosol + SOA) of diesel vehicles in EURO 4–6 were reduced by up to 95% compared to those in EURO 2–3. The expected SOA yield increased through the hot-condition combustion section of a vehicle, over the SOA range of 0.2–155 μg m−3. These results provide the necessary data to analyze all types of SOA generated by the gas-phase oxidation in vehicle emissions in metropolitan areas.

This study investigated the effects of various ethanol-gasoline blends on the hazardous air pollutants (HAPs) emissions from a wall-guided direct injection passenger vehicle. The fuel economy (FE) as well as regulated and unregulated gaseous emissions was evaluated on a chassis dynamometer using the federal test procedure (FTP-75) mode. Five fuels with varying ethanol contents of E0, E10, E30, E50, and E85 were prepared by blending ethanol into commercial gasoline on a volumetric basis and were analyzed each fuel specification. The engine control schemes of fuel injection quantity for various ethanol blends were adjusted to optimize the engine starting capability, vehicle drivability and emissions performance. The FE of the E85 fueled vehicle decreased by 29% relative to gasoline fuel due to the low energy content of ethanol. Blending ethanol into gasoline produced a dramatic decrease of particulate emission, because pure ethanol has no aromatic compounds and carbon content lower than that of gasoline. As a result, nano-particles were rarely emitted in the vehicle tests of fuels with more than 30% ethanol. Carbonyl compounds emissions, which originate from partial oxidization or incomplete combustion of ethanol, also rose sharply as the ethanol content increased, while volatile organic compound (VOC) emissions were reduced considerably with medium- and high-ethanol formulations due to the lower proportion of aromatic components in these fuels.

In this study, the regulated, particulate, and unregulated emissions, and the fuel economy (FE) from a direct injection spark ignition (DISI) vehicle were investigated on a chassis dynamometer. Two vehicle test cycles, the congested urban (NIER03) and rural modes (NIER09), which reflect vehicle driving patterns in Korea, were tested with varying ethanol contents of gasoline (E0), and low- (E10), medium- (E30 and E50), and high-ethanol blended fuels (E85). The particle number (PN) concentration from E0 was substantially reduced by one or two orders of magnitude with medium- or high-ethanol blended fuels, respectively. The E10 fuel showed the highest PN concentration because of the physicochemical mixture properties of the azeotropic characteristics. As the ethanol fraction increased, the particle sizes shifted to smaller sizes that were dependent on the vehicle test modes and oxygen proportions in the fuels. The regulated and unregulated emissions showed close relationships with the vehicle test modes and ethanol blends. Vehicle running with frequent idle-stops at an extremely low speed and dynamic transient driving under NIER03 showed higher BTEX emissions than the NIER09 mode, and produced lower emission levels due to the higher oxygen and lower aromatic proportions of the ethanol blends. Compared to the NIER03 mode, the CO2 emissions and FEs under the NIER09 mode were substantially improved, with a higher vehicle speed and more energy efficient engine operation points. The low energy contents of the E85 fuel resulted in slight increases in the CO2 emissions and reductions in the FEs of the NIER modes.

The number of investigation on the fuel efficiency and the emission characteristics of diesel vehicles under steady-state operation and under transient operation has been carried out, and the knowledge obtained from these research provides substantial information to analyze real driving emissions of diesel vehicles. Detailed information on the fuel use and the emission under the real driving condition, however, are still required in order to provide substantial information to analyze and predict the fuel use and gaseous emissions from a diesel vehicle driving various real-world conditions. This work aims to characterize the fuel use and the gaseous emissions such as NOx, unburned HC, CO, and CO2 from light-duty diesel vehicles, complying with Euro 6b emissions standards, driving the route fully reflected various real-world driving conditions. The experiment was carried out with a Portable Emissions Measurement System (PEMS) including a Global Positioning System (GPS). We evaluated the fuel used and the overall gaseous emissions in various road conditions, and the vehicle specific powers (VSPs) with determining the road load coefficients and regression coefficient by multiple linear regression analysis. Furthermore, this work also revealed the fuel use and the emissions per VSP of vehicles in these six different conditions.

Mobile source air toxic (MSAT) emissions from a direct injection spark ignition (DISI) passenger vehicle fueled with gasoline and liquid phase liquefied petroleum gas (LPG) were compared using a chassis dynamometer under several in-use vehicle driving conditions. For operation of a dedicated LPG-DI engine, low-pressure fuel systems were specially installed and various engine control parameters were recalibrated considering different chemical properties of LPG. A series of the National Institute of Environmental Research (NIER) modes for determining the emission factors of in-use vehicles in Korea were chosen to quantify not only the regulated emissions with particles but also the unregulated emissions of carbonyls, BTEX, and PAHs from a DISI light-duty vehicle (LDV) with gasoline and LPG. The regulated and particle emissions of LPG-DI vehicles showed strong reduction, and the proportions of sub-23 nm particles were 32–35% in gasoline and 50–65% in LPG. The results revealed that the levels of the MSAT emissions from a DISI engine were closely related to the driving patterns and the fuel properties. A substantial reduction of regulated emissions, particulates, BTEX, and particle-bound PAH emissions was achieved from a LPG-DI vehicle in real driving conditions. Carbonyl compounds acetaldehyde and acrolein showed significant increment from a LPG-DI vehicle.

Because increased food delivery service and quick delivery service using motorcycle, registration numbers of motorcycles were sharply increased and it could contribute on worsening air quality. In this study, two models(50cc, 125cc) of motorcycle were tested by using three types of engine oil. Two motorcycles were tested with CVS-40 mode for emission characteristics such as CO, THC, NOx, Elemental Carbon(EC), Organic Carbon(OC), sulfate, soot and SOF(soluble organic fraction). Result of according to three types of lubricants which included phosphorus, sulfate ash impacted to particle matters so "C" lubricants is more higher PM than "A", "B" lubricants in this research.

Adulterations fuel have been using in the vehicle in these days. Because gasoline, diesel prices are rising every day. sopeople find more cheap price fuel. Adulterations fuel caused a serious air pollution problems. Adulteration fuel were madefrom waste engine oil, waste paint. According to Government regulations permit to be used recycle fuel(adulteration fuel)only in industrial boiler. Unburned fuel pollutants are effected to human health. In this paper, the hazardous air pollutantscharacteristics in the diesel vehicles according to adulterations of vehicle fuels were carried out in the NEDC test mode inchassis dynamometer. It is revealed that the all of the regulation pollutants (THC, NOx, CO and PM) emission in the adul-terations of vehicle fuels was increased also the green house gas, CO 2 was increased. In the hazardous air pollutants char-acteristics, the VOCs(Volitile Organic Compounds) BTEX(Benzene, Toluene, Ethylbenzene, Xylene) emissions in the adulterationsof vehicle fuels showed higher level than these in the diesel fuels.

The purpose of this study was to investigate the fuel properties, droplet atomization, combustion performance, and exhaust emission characteristics of gasoline–diesel direct blended fuels in a four-cylinder diesel engine. The gasoline fuel was blended as a volumetric fraction of conventional diesel fuel. The droplet size of test fuels was measured using a phase Doppler particle analyzer (PDPA), and the combustion and emission characteristics were investigated for a four-cylinder diesel engine with a common-rail injection system and emission analyzer. In this study we found that increasing the gasoline volume fraction decreased the fuel density, kinematic viscosity, and surface tension. The temperature for 10% distillation (T10) decreased as the gasoline fraction increased. The blending of gasoline caused a decrease in droplet size by increasing the small droplets and decreasing the large droplets because the surface tension decreased with the addition gasoline fuel, thereby inducing an increase in droplet instability. On the other hand, gasoline blending resulted in an extension of the ignition delay and the formation of a more homogeneous mixture. These combustion characteristics caused the simultaneous reduction of ISNOx and ISsoot. However, the ISHC and ISCO emissions were slightly increased. The difference in ISHC and ISCO emissions between pure diesel and gasoline blended diesel fuels decreased as the engine load increased. An increase in engine load diminished the effects of gasoline blending on combustion performance and exhaust emissions.

This investigation decribes the effect of the combustion and emission characteristics of HCNG engine according to the high purity hydrogen contents. The HCNG fuel was made by the mixture with a high purity hydrogen () and a natural gas. The test vehicle was applied to the bi-fuel (Gasoline and CNG) system and this system was modified from the fuel supply and fuel tank. In addition, the three premixed HCNG fuels with mixed rate of 10, 20 and 30% of hydrogen were used to maintain the safety. In order to analyze the combustion characteristics of HCNG and CNG, the fuel was injected in the combustor with constant volume. The exhaust emission from light duty vehicle with bi-fuel system was analyzed by a chassis dynamometer and emission analyzer. From these results, the reduction rate of NOx emission increased in the HCNG fuel and emission amount of THC and CO shows a similar level with CNG fuel. This study can be utilized the basic data for the development of a new business plans related with HCNG engines.

In this study, to evaluate the potential of a dedicated liquefied petroleum gas-direct injection (LPG-DI) vehicle, regulated and unregulated emissions from a light-duty gasoline direct injection (GDI) vehicle were compared. The vehicle tests were performed on a chassis dynamometer with constant volume sampler (CVS) over the federal test procedure (FTP)-75, highway fuel economy test (HWFET), and new European driving cycle (NEDC), which include the engine starting, transient and warm-up operation. The emissions of total hydrocarbon (THC) as well as nitrogen oxides (NOx) and nano-particles from the LPG-DI vehicle showed significantly superior performance relative to gasoline with excellent gaseous mixture preparation and low carbon fuel. The CO 2 emission of the LPG-DI vehicle decreased approximately 4–6% compared to the GDI vehicle. Aldehydes formation was influenced by vehicle test modes, such as the proportions of vehicle low speed patterns as well as long idle duration and the inclusion of engine warm-up periods. Formaldehyde, acetaldehyde, and acrolein compounds significantly increased with the LPG-DI vehicle, and this increase was related with partial oxidation during the combustion process of butane and propane. Except for the slightly increase in the HWFET mode, strong decreases in BTEX were observed with the application of LPG fuel in the FTP-75 and NEDC mode. It was found that the regulated and unregulated emissions were closely related to both the vehicle driving patterns and fuel compositions.

SULEV (Super Ultra Low Emission Vehicle) which is one of the emission standards in Fleet Average System introduced to Korea from 2009 is known as the most severe standard to achieve with internal combustion engine. Considering low sales volume of hybrid vehicles in Korea, vehicle manufacturers are required to develop SULEV technologies for conventional gasoline and LPG vehicles to meet the future Fleet Average standard. In this study, the comparison of emissions has been made between SULEV developed and ULEV LPG vehicles mainly produced in this time. To estimate the emission reduction of SULEV vehicles, CVS-75 and NIER test modes have been used. CVS-75 has been used for emission certification of gasoline and LPG vehicles. NIER modes cover various average vehicle speed and reflect Korean real driving patterns better than CVS-75. The test results show that SULEV LPG vehicles have very high potential to reduce in regulated emissions, in green house gases and toluene in VOCs. However, SULEV LPG vehicles don`t affect much on the reduction of CO and total green house gases.

The air pollutants from vehicle exhaust gas are affected by many factors including fuel qualities, engine and vehicle technologies, driving patterns. In particular, fuel qualities and after-treatment devices could directly affect the emission level of pollutants. The pollutant reduction characteristics that caused by enforced fuel quality standard were analyzed. Three types of test fuel were selected in accordance with Korean automotive fuel standard in 2006, 2009, 2012 and used for vehicle emission test in chassis dynamometer. European COPERT correction equation of fuel impact was considered as reference information to quantify the vehicle emission test results. The contribution rates of exhaust emission by COPERT correction equation showed that aromatic compounds and oxygen contents in gasoline fuel was most important. In case of diesel fuel, cetane index and polycyclic aromatic compounds accounted for the greater part. The exhaust emission effects by COPERT correction equation revealed that CO and VOC was increased 0.86%, 1.57% respectively in after 2009 gasoline when compared to before 2009 gasoline fuel. In case of light-duty diesel vehicle CO, VOC and PM were decreased in range of 3~7%. The result from this study could be provided for developing future fuel standards and be used to fundamental information for Korean clean air act.