bluuebunny/crossref_metadata_2025_split huggingface dataset:
Residential particulate matter, proximity to major roads, traffic density and traffic volume as risk factors for preterm birth in California
Authors: Costello Jean M. , Steurer Martina A. , Baer Rebecca J. , Witte John S. , Jelliffe‐Pawlowski Laura L. 
Published: November 2021

AbstractBackgroundWhile pollution from vehicle sources is an established risk factor for preterm birth, it is unclear whether distance of residence to the nearest major road or related measures like major road density represent useful measures for characterising risk.ObjectiveTo determine whether major road proximity measures (including distance to major road, major road density and traffic volume) are more useful risk factors for preterm birth than other established vehicle‐related measures (including particulate matter <2.5 μm in diameter (PM2.5) and diesel particulate matter (diesel PM)).MethodsThis retrospective cohort study included 2.7 million births across the state of California from 2011–2017; each address at delivery was geocoded. Geocoding was used to calculate distance to the nearest major road, major road density within a 500 m radius and major road density weighted by truck volume. We measured associations with preterm birth using risk ratios adjusted for target demographic, clinical, socioeconomic and environmental covariates (aRRs). We compared these to the associations between preterm birth and PM2.5 and diesel PM by census tract of residence.ResultsFindings showed that whereas higher mean levels of PM2.5 and diesel PM by census tract were associated with a higher risk of preterm birth, living closer to roads or living in higher traffic density areas was not associated with higher risk. Residence in a census tract with a mean PM2.5 in the top quartile compared with the lowest quartile was associated with the highest observed risk of preterm birth (aRR 1.04, 95% CI 1.04, 1.05).ConclusionsOver a large geographical region with a diverse population, PM2.5 and diesel PM were associated with preterm birth, while measures of distance to major road were not, suggesting that these distance measures do not serve as a proxy for measures of particulate matter in the context of preterm birth.
Growth and photosynthetic traits differ between shoots originated from axillary buds or from adventitious buds in Populus balsamifera L. cuttings
Authors: Wang Lei , Dang Qing‐Lai 
Published: November 2021

AbstractBud development influences shoot branching and the plasticity and adaptability of plants. To explore the differences of post‐embryonic development of different types of buds, shoots originated from adventitious buds and axillary buds of cuttings in two populations of balsam poplar (Populus balsamifera L.) were investigated for differences in leaf morphology, photosynthetic and growth characteristics, and the effects of a carbonic anhydrase (CA) inhibitor on CA activity, photosynthesis and mesophyll conductance (gm). The results showed that axillary buds produced ovate first few leaves and longer shoots while adventitious buds produced lanceolate first few leaves with higher specific leaf area (SLA). There were no significant differences in leaf area‐based photosynthetic rate (An), maximum carboxylation rate (Vcmax), and maximum electron transport rate (Jmax) between shoots originated from the two bud types. Based on the principal component analysis, shoots of adventitious bud origin grouped on daytime respiration and SLA, while cuttings from axillary buds clustered toward the opposite direction of quantum yield and light saturation point. Shoots originated from different types of buds had different growth rates and biomass, but the direction of the differences varied with the population of the mother tree. The two populations differed in An, gm, and relationships between CA, An, and gm. There were differences in post‐embryonic growth traits of shoots from axillary buds and those from adventitious buds, which may be an adaptive strategy for regeneration under different light conditions.
Spatial regulation of RBOHD via AtECA4‐mediated recycling and clathrin‐mediated endocytosis contributes to ROS accumulation during salt stress response but not flg22‐induced immune response
Authors: Lee Jihyeong , Hanh Nguyen Hong , Park Youngmin , Lin Jinxing , Hwang Inhwan 
Published: November 2021

SUMMARYVarious environmental stresses can induce production of reactive oxygen species (ROS) to turn on signaling for proper responses to those stresses. Plasma membrane (PM)‐localized respiratory burst oxidase homologs (RBOHs), in particular RBOHD, produce ROS via the post‐translational activation upon abiotic and biotic stresses. Although the mechanisms of RBOHD activation upon biotic stress have been elucidated in detail, it remains elusive how salinity stress activates RBOHD. Here, we present evidence that trafficking of PM‐localized RBOHD to endosomes and then its recycling back to the PM is critical for ROS accumulation upon salinity stress. ateca4 plants that were defective in recycling of proteins from endosomes to the PM and clc2‐1 and chc2‐1 plants that were defective in endocytosis showed a defect in salinity stress‐induced ROS production. In addition, ateca4 plants showed a defect in transient accumulation of GFP:RBOHD to the PM at the early stage of salinity stress. By contrast, ateca4 plants showed no defect in the increase in the ROS level and accumulation of RBOHD to the PM upon flg22 treatment as wild‐type plants. Based on these observations, we propose that factors involved in the trafficking machinery such as AtECA4 and clathrin are important players in salt stress‐induced, but not flg22‐induced, ROS accumulation.
Effect of Butanol on the Performance of DeNOx Aftertreatment Systems of a Diesel Vehicle Under WLTC Driving Conditions
Authors: Calle-Asensio Alejandro , Hernández Juan José , Rodríguez-Fernández José , Domínguez-Pérez Víctor 
Published: November 2021

Abstract
Advanced biofuels and electrofuels, among which are medium-long chain alcohols, have gained importance in the transport sector with the enforcement of the EU Renewable Energy Directive (2018/2001). In parallel, last European emission regulations have become much more restrictive regarding NOx, so vehicle manufacturers have been forced to incorporate lean NOx trap (LNT) and/or selective catalytic reduction (SCR). Thus, the combination of modern DeNOx devices and the upcoming higher contribution of sustainable biofuels is a new challenge. In this work, two Euro 6 diesel vehicles, one equipped with LNT and the other with ammonia-SCR, have been tested following the Worldwide harmonized Light-duty vehicles Test Cycle (WLTC) at warm (24°C) and cold (−7°C) conditions using conventional diesel fuel and a diesel-butanol (90/10% vol.) blend. While the effect of butanol on the LNT efficiency was not significant, its influence on the SCR performance was notable during the low and medium-speed phases of the driving cycle, mainly under warm climatic conditions. Despite of the lower NOx concentration at the catalyst inlet, the worst efficiency of the SCR with butanol could be attributed to hydrocarbons deposition on the catalyst surface, which inhibits the NOx reduction reactions with ammonia. Moreover, the LNT was not sensitive to the ambient temperature while the SCR performance greatly depended on this parameter.
Experimental Investigation of a Simulated Byproduct Fuel Mixture From the Cl-ODH Process in a Spark-Ignition Engine
Authors: Gore Matt , Nonavinakere Vinod Kaushik , Fang Tiegang 
Published: November 2021

Abstract
The study investigates a fuel mixture with ethane and methane as active species and a high dilution of CO2 for application in a spark-ignition (SI) engine. The simplified fuel mixture used is a byproduct of a chemical looping based oxidative dehydrogenation (Cl-ODH) process to convert ethane to ethylene. The byproduct gas mixture has a concentration of 41% CO2, 40% ethane, and 5% methane by weight along with other minor compounds. Varying mixtures of ethane and methane were selected and combined with between 42 to 46 percent by weight CO2 to evaluate the viability and efficiency of this fuel to operate in existing internal combustion engines as a means for reducing emissions and improving the process efficiency of the Cl-ODH process. An experimental test stand was built based on a 13 hp gasoline generator with modified gas induction. The engine was also instrumented for data acquisition from the engine. A gas metering and mixing system was installed to precisely control the mass of gases induced into the engine. Various instrumentation was installed on the engine to monitor in-cylinder pressure, temperature at various locations, emissions, and fuel and airflow rates. Varying loads were applied and flow rates of the gases were induced to simulate different mixtures. It was found that under a high load, the mixed gas was able to generate comparable thermal efficiency and power to gasoline. But under no load or a part load condition the indicated thermal efficiency was found to be lower than that of gasoline. Further, the mixed gas also resulted in lower CO and NOx emissions compared to gasoline. The application of this work is an alternative fuel for existing engines that with little modification can operate effectively and benefit the overall process of ethylene generation.
Ammonia Slip Estimation Based on ASC Control-Oriented Modelling And OBD NOx Sensor Cross-Sensitivity Analysis
Authors: Piqueras Pedro , Pla Benjamín , Sanchis Enrique José , Aronis André 
Published: November 2021

Abstract
The incoming emission regulations for internal combustion engines are gradually introducing new pollutant species, which requires greater complexity of the exhaust gas aftertreatment systems concerning layout, control and diagnostics. This is the case of ammonia, which is already regulated in heavy-duty vehicles and to be included in the emissions standards applied to passenger cars. The ammonia is injected into the exhaust gas through urea injections for NOx abatement in selective catalytic reduction (SCR) systems and can be also generated in other aftertreatment systems as three-way catalysts. However, ammonia slip may require removal on a dedicated catalyst called ammonia slip catalyst (ASC). The set consisting of the urea injection system, SCR and ASC requires control and on-board diagnostic tools to ensure high NOx conversion efficiency and minimization of the ammonia slip under real driving conditions. These tasks are based on the use of NOx sensors ZrO2 pumping cell-based, which present as a drawback high cross-sensitivity to ammonia. Consequently, the presence of this species can affect the measurement of NOx and compromise SCR-ASC control strategies. In the present work, a methodology to predict ammonia and NOx tailpipe emissions is proposed. For this purpose, a control-oriented ASC model was developed to use its ammonia slip prediction to determine the cross-sensitivity correction of the NOx sensor placed downstream of the ASC. The model is based on a simplified solution of the transport equations of the species involved in the main ASC reactions. The ammonia slip model was calibrated using steady- and quasi-steady-state tests performed in a Euro 6c diesel engine. Finally, the performance of the proposed methodology to predict NOx and ammonia emissions was evaluated against experimental data corresponding to Worldwide harmonized Light vehicles Test Cycles (WLTC) applying different urea dosing strategies.
A Numerical Investigation on Mixing Characteristics of Natural Gas Jets With High-Pressure Injection
Authors: Liu Long , Dai Tianyang , Xiong Qian , Qian Yuehua , Liu Bo 
Published: November 2021

Abstract
With increasingly stringent emissions limitation of greenhouse gas and atmospheric pollutants for ship, the direct injection of natural gas on the cylinder head with high-pressure injection is an effective method to make a high power output and decrease harmful gas emissions in marine natural gas dual fuel engines. However, the effects on mixing characteristics of high-pressure natural gas underexpanded jet have not been fully understood. Especially, the injection pressure is up to 30 MPa with large injection quantity and critical surrounding gas conditions for the low-speed two-stroke marine engine.
Therefore, this research is focused on the flow and mixing process of the natural gas jet with high-pressure injection under the in-cylinder conditions of low-speed two-stroke marine engine. The gas jet penetration, the distribution of velocity and density, the equivalence ratio and air entrainment have been analyzed under different nozzle hole diameters by numerical simulation. The effects of surrounding gas conditions including pressure, temperature and swirl ratio on air entrainment and equivalence ratio distribution were studied in detail. From the numerical simulation, it is found that the mixing characteristics of natural gas jet can be improved under in-cylinder conditions of higher ambient temperature and swirl ratio, which is relevant to the low-speed two-stroke marine engine.
Hydrocarbon Species Impact on NO to NO2 Conversion in a Compression Ignition Engine Under Low Temperature Combustion Conditions
Authors: Gupta Nupur , Yu Xiao , LeBlanc Simon , Eaves Nick , Zheng Ming 
Published: November 2021

Abstract
Low temperature combustion has proved to be beneficial for low NOx and particulate matter emissions. Renewable fuels, such as biodiesel, alcohol fuels, and ether fuels can further decrease the carbon footprint of the engine. The NO to NO2 ratio in engine out NOx emissions has shown dependency on the concentration of hydrocarbon emissions. This relationship has a significant impact on the design of exhaust after-treatment systems. However, the effect of the renewable fuels on NO to NO2 conversion process is less understood. This paper investigates the impact of DME and propane on the in-cylinder conversion of NO to NO2 in a compression ignition engine. Firing test under low temperature combustion condition is first performed to demonstrate the impact of HC concentration on exhaust NO concentration and composition. Then, motoring tests are performed with a mixture of the HC and NO dosed into the engine intake manifold. The simplified testing scenario makes it easier to understand HC-NO interaction. To simplify the process of understanding the difference in fuel behavior a study of NO to NO2 conversion as a resolution of engine cycle is conducted using a Gas Sampling Valve which is capable of collecting in-cylinder gases at varying crank-angles. The FTIR data from these compression tests can help assist future mechanism studies to be performed. This study aims to describe the impact of the two fuels on the NO to NO2 conversion process and the boundary conditions at which these differences occur.
Investigation of Valvetrain Dynamics Using Transient Dynamic Simulation in ANSYS
Authors: Koli Ashish , Rao Nikhil , Parekar Vinod 
Published: November 2021

Abstract
Engine valvetrain is one of the complex mechanisms in internal combustion engine as it involves many components namely, cam, pushrod, rocker lever, crosshead, intake and exhaust valves etc. Due to many components, their interactions with each other and presence of valve lash makes the system complicated to simulate. Typically, engine system level valvetrain dynamic simulation is performed in 1D software.
Aim of this study is to understand the physics governing interactions and motion of the components in the valvetrain. This is done by simulating an inline 6-cylinder engine valvetrain mechanism through transient dynamic analysis in Ansys. This paper describes an approach used to simulate the valvetrain mechanism in Ansys and associated learnings. Finite Element Analysis model considers actual stiffnesses of all components. Appropriate joints/contacts are used to model the interactions. The comparative assessment of the valvetrain forces between Ansys results and 1D simulation results shows a good match. Further, 3D simulation in Ansys captures the key characteristics of valvetrain like crosshead tilting, uneven valve actuations and closing. It is also able to predict uneven contact and polishing observed on valve tip face.
Overall, this study helped to ascertain the validity of 3D FEA method. This method also enhances the understanding of the valvetrain dynamics which can be helpful in further design improvements. This paper also includes a discussion on further steps to improve analysis model to make it more realistic e.g. including hot valve lash, valve seat wear etc. These improvements will help to understand effects of valve lash on valve velocities, sudden impact loads on valves, valve stresses/fatigue, pushrod buckling etc.
A Comparison of Injection, Spray, and Combustion Characteristics for Non-Eroded and Eroded Multi-Hole Fuel Injectors
Authors: Magnotti Gina M. , Nunno A. Cody , Kundu Prithwish , Tekawade Aniket , Sforzo Brandon A. , Kastengren Alan L. , Powell Christopher F. , Som Sibendu 
Published: November 2021

Abstract
It is well known that cavitation erosion in fuel injectors can prevent reliable engine performance after only several thousand hours of operation. However, current simulation tools lack the ability to link flow predictions within the fuel injector to both the efficacy of combustion strategies and lifetime of the injector. Multiphase flow simulation predictions were studied and compared between an informed baseline injector geometry and an x-ray scanned eroded injector geometry. Overall, erosion was found to decrease the fuel mass delivery and injection velocities. A two-stage static coupling approach was employed to link the predicted injection conditions from non-eroded and eroded injectors with the external spray simulations under reacting conditions. Combustion modeling in this coupled approach was carried out using the Unsteady Flamelet Progress Variable approach with a detailed chemical mechanism for n-dodecane, comprising of 2,755 species and 11,173 reactions. Erosion in the injectors led to lower rates of spray penetration in comparison to the baseline configurations. Analysis of the reacting spray simulations revealed an insensitivity of ignition to erosion, yet shorter lift off lengths, higher levels of the soot, and lower levels of NOx were predicted in the eroded injector.
Evaluating Diesel/Biofuel Blends Using Artificial Neural Networks and Linear/Nonlinear Equations
Authors: Kessler Travis , Schwartz Thomas , Wong Hsi-Wu , Mack J. Hunter 
Published: November 2021

Abstract
The use of biomass-derived additives in diesel fuel mixtures has the potential to increase the fuel’s efficiency, decrease the formation of particulate matter during its combustion, and retain the fuel’s behavior in cold weather. To this end, identifying compounds that enable these behaviors is paramount. The present work utilizes a series of linear and non-linear equations in series with artificial neural networks to predict the cetane number, yield sooting index, kinematic viscosity, cloud point, and lower heating value of multi-component blends. Property values of pure components are predicted using artificial neural networks trained with existing experimental data, and these predictions and their expected errors are propagated through linear and non-linear equations to obtain property predictions for multi-component blends. Individual component property prediction errors, defined by blind prediction median absolute error, are 4.91 units, 7.84 units, 0.06 cSt, 4.00 °C, and 0.55 MJ/kg for cetane number, yield sooting index, kinematic viscosity, cloud point, and lower heating value respectively. On average, property predictions for blends are shown to be accurate to within 6% of the blends’ experimental values. Further, a multitude of compounds expected to be produced from catalytically upgrading products of fast pyrolysis are evaluated with respect to their behavior in diesel fuel blends.
Measurement of Air-Fuel Mixing in a Diesel Spray at Engine Relevant Conditions Using UV-VIS DBI Diagnostic
Authors: Godbold Conner , Poursadegh Farzad , Bibik Oleksandr , Genzale Caroline 
Published: November 2021

Abstract
Due to the non-premixed nature of diesel combustion, mixing prior to the reaction zone has proven to be one of the primary factors in emissions formation. Therefore, the advancement of diagnostics used to measure mixing fields in diesel applications is imperative for a greater understanding of how in-cylinder emissions mitigation techniques operate. Towards this goal, we have recently demonstrated the use of a high-speed two-wavelength extinction imaging measurement, UV-VIS DBI, for time-resolved measurements of mixing in a diesel spray. This diagnostic operates by back-lighting the spray with ultra-violet and visible illumination. The visible illumination is selected at a non-absorbing wavelength, such that the visible light is only attenuated by liquid droplet scattering, enabling discrete detection of the liquid-vapor mixture and pure vapor phases of the spray. For this work, Ultraviolet and visible light are generated using a ND:YAG pumped frequency-doubled tunable dye laser operating at 9.9 kHz . The simultaneous UV-Visible illumination is used to back-illuminate a vaporizing diesel spray, and the resulting extinction of each signal is recorded by a pair of high-speed cameras. Using an aromatic tracer (naphthalene, BP = 218 °C) in a base fuel of dodecane (BP = 215–217 °C), the UV illumination (280 nm) is absorbed along the illumination path through the spray, yielding a projected image of line-of-sight optical depth that is proportional to the projected fuel vapor concentration in the pure vapor region of the spray. In this paper, a new method of determining the absorption coefficient for the pure-vapor phase of the spray will be discussed, along with showing how an Inverse-Abel transform can be used to compute planar concentration data from the projected concentration data yielded by the diagnostic. This diagnostic and data processing is applied to diesel sprays from two Bosch CRI3-20 ks1.5 single-orifice injectors (140 μm and 90 μm orifice diameters) injecting into a nonreacting high-pressure and temperature nitrogen environment using a constant-flow, optically-accessible spray chamber operating at 60 bar and 900 K. The mixing data produced agrees well with previously existing mixing data, which further instills confidence in the diagnostic, and gives the diesel combustion community access to mixing field data for a 140 μm orifice diameter injector at a 60 bar and 900 K condition.