Exhaust Pollutants Research Articles

Applying similar modeling to study vehicle exhaust transport in a confined mining space

To scientifically and effectively manage exhaust pollution in underground confined spaces and reduce hazards from personnel exhaust exposure, a systematic study of the distribution characteristics of diesel locomotive exhaust emissions in mines is needed. Aiming at large underground coal mining operations, an experimental platform for the physical simulation of vehicle exhaust transport in restricted spaces is designed and created. The Hongliulin Coal Mine in Shaanxi Province, China, is used as a prototype, and the platform consists of a coal mining face system, ventilation system, exhaust emission system, monitoring and surveillance system, and control platform. The experimental platform with carbon dioxide simulation of diesel exhaust pollution, in the role of different wind speed, the concentration of carbon dioxide is a downward trend, the wind speed is in the low wind speed on the 0.2 m of the concentration difference of 25.75%; the experimental platform exhaust transport process presents a clear “three-zone” change rule; experimental platform carbon dioxide concentration and the field nitrogen dioxide concentration change trend is consistent. The platform functions and features can provide guidance for mine exhaust management and exhaust exposure hazard prevention and control.

Biofuel blends and nano-additives: a sustainable approach to diesel engine performance and emissions improvement

Abstract The utilization of compression ignition (CI) diesel engines has seen a substantial increase in recent years owing to their numerous advantages. However, the widespread adoption of these engines has also significantly contributed to environmental pollution issues, with diesel engines being recognized as major global contributors to exhaust emissions-related pollution. To address this issue, comprehensive research has been carried out on both emissions from diesel exhaust pollutants and advanced after-treatment technologies for emission control. This study aims to evaluate the efficiency and emissions of diesel fuel mixed with various ratios of biofuel derived from Karanja seeds (B10, B15, and B20). Among the different blends examined, B20 demonstrated superior performance in terms of brake thermal efficiency (BTE) and brake-specific fuel consumption (BSFC), along with lower levels of hydrocarbon (HC) and carbon dioxide (CO2) emissions compared to pure diesel. Further, the impact of nanoadditives, specifically titanium dioxide (TiO2), at different concentrations (80 ppm, 100 ppm, and 120 ppm), on B20 blends was evaluated. The findings indicated that B20 blended with 100 ppm of TiO2 exhibited superior performance in terms of BTE, BSFC, and lower emissions of HC, CO2, nitrogen oxides (NOx), and carbon monoxide (CO). From the results, the BTE increases from 1% to 33%, illustrating enhanced thermal efficiency under similar conditions. The average BSFC across all loads and speeds in the table is approximately 0.89 kg/kWh, while the average BTE stands at approximately 23.1%.

The plausible pathway of air pollutants and the respiratory system among COVID-19 patients: a systematic literature review

Studies evidence links air pollution to increased risk of COVID-19 infection and severity during the pandemic. Nonetheless, those studies are unable to discuss specific pollutants, such as particulate matter, Sox, and NOx. This systematic literature review aimed to summarize the most recent studies on the links between pollutants and their effects on the respiratory system, in this case, mostly on COVID-19 patients. We searched using electronic databases (PubMed, Springer, ScienceDirect, and Sage) in May 2023. The keywords chosen were connected to respiratory diseases and air pollution. All relevant studies published in peer-reviewed journals between 2020 and 2023 and written in English were considered. We excluded letters and non-original articles. Relevant keywords were used to select papers. A total of 11 articles are eligible to be included in the present review study. It was reported that countries with a high prevalence of COVID-19 also have greater concentrations of surface air particles (PM10 and PM2.5) due to vehicle exhaust and industrial pollution. PM-virus aggregates spread easier across the lungs and the top respiratory system, facilitating viral attachment to the lung epithelium. This study found that tiny particles with an aerodynamic dimension fewer than 2.5 μm (PM2.5) or ten μm (PM10) have the most significant potential influence on the respiratory system compared to other pollutants.

Regulating the interaction between PdCu bimetals and MgAl1.82Ce0.18O4 spinel for three‐way catalysis

Three‐way catalysis represents a pivotal technology for converting automobile exhaust pollutants into non‐toxic gases. Substituting some noble metals with transition metals is considered a promising way to reduce catalyst costs. Herein, we have investigated the catalytic potential of different configurations of Pd‐Cu catalysts prepared by impregnation (PdCu/MA), sol‐gel (PdCu‐MA), impregnation with physical mixing (Pd/Cu/MA) and sol‐gel with physical mixing (Pd/Cu‐MA) to modify the interaction of Pd/Cu and MgAl1.82Ce0.18O4 (MA) spinel in this comparative study. The different structures in these catalysts lead to different catalytic performances. PdCu/MA exhibits the best three‐way catalytic performance, which owe to the small‐sized PdCu particles with high Pd2+ content (45.3%) and optimal interaction of Pd/Cu particles and MgAl1.82Ce0.18O4 support. Furthermore, comprehensive CO‐DRIFTS, H2‐TPR, and O2‐TPD analyses discover that the metal‐support interaction is beneficial to enhance the catalytic performance in three‐way catalysis. Overall, we demonstrated that the interaction between PdCu bimetals and support can regulate the electronic state of Pd, thereby enhancing the use and efficiency of noble metals.

Changes in source composition of wet nitrate deposition after air pollution control in a typical area of Southeast China

In recent years, China has adopted numerous policies and regulations to control NOx emissions to further alleviate the adverse impacts of NO3−-N deposition. However, the variation in wet NO3−-N deposition under such policies is not clear. In this study, the southeastern area, with highly developed industries and traditional agriculture, was selected to explore the variation in NO3−-N deposition and its sources changes after such air pollution control through field observation and isotope tracing. Results showed that the annual mean concentrations of NO3−-N in precipitation were 0.67 mg L−1 and 0.54 mg L−1 in 2014–2015 and 2021–2022, respectively. The average wet NO3−-N depositions in 2014–2015 and 2021–2022 was 7.76 kg N ha−1 yr−1 and 5.03 kg N ha−1 yr−1, respectively, indicating a 35% decrease. The δ15N–NO3− and δ18O–NO3− values were lower in warm seasons and higher in cold seasons, and both showed a lower trend in 2021–2022 compared with 2014–2015. The Bayesian model results showed that the NOx emitted from coal-powered plants contributed 53.6% to wet NO3−-N deposition, followed by vehicle exhaust (22.9%), other sources (17.1%), and soil emissions (6.4%) during 2014–2015. However, the contribution of vehicle exhaust (33.3%) overpassed the coal combustion (32.3%) and followed by other sources (25.4%) and soil emissions (9.0%) in 2021–2022. Apart from the control of air pollution, meteorological factors such as temperature, precipitation, and solar radiation are closely related to the changes in atmospheric N transformation and deposition. The results suggest phased achievements in air pollution control and that more attention should be paid to the control of motor vehicle exhaust pollution in the future, at the same time maintaining current actions and supervision of coal-powered plants.

Effect of ZnO nanoparticle on combustion and emission characteristics of a diesel engine powered by lemongrass biodiesel: an experimental approach

Biodiesel (BD) is one of the efficient alternative fuels for diesel engines (DE) which can be employed sans any modifications. The present study is focused on the extraction of BD from a lemongrass plant and analyzing combustion, efficiency, and emission characteristics of the DE by adding NPs at different concentrations to reduce both hydrocarbon, carbon monoxide, and NOx emissions simultaneously from the DE. The fuel samples were prepared by adding different dosages of zinc oxide nanoparticles (ZnO NPs) with neat lemongrass biodiesel (LGB) such as 50 ppm, 100 ppm, 150 ppm, 200 ppm, and 250 ppm per liter. From the results, it is found that the properties of BD were improved by the addition of ZnO NPs and it increased oxygen concentration in the sample resulting in better combustion and lower exhaust pollutants. The DE tested with the LGB + 150 ppm sample has registered maximum brake thermal efficiency (BTE) and lower specific fuel combustion (SFC) for all loading conditions compared to other samples. The value of heat release rate (HRR) and in-cylinder pressure are higher for LGB + 150 ppm due to its specific properties compared to other LGB blends. The presence of ZnO NPs in LGB has reduced harmful emissions from the DE such as carbon monoxide (CO), hydrocarbon (HC), oxides of nitrogen (NOx), and smoke by 4.01%, 5.56%, and 19.01%, when compared to neat LGB.

Ecological implications of accumulation of PTEs and PAHs deriving from fuel exhausts in coastal marine primary producers

Anthropogenic activities, mainly in the form of local fuel exhausts and inputs from the coastline, heavily affect ecosystems at the interface between terrestrial and marine realms, impairing their functionality and the services they provide. Due to the central role of primary producers in trophic webs, their sessile nature and ethical concerns implied in experiments on animals, pollutant analyses in both sediments and macrophytes assume special relevance in assessing pollutant transfers from the abiotic to biotic compartments and their possible transfer through trophic webs. With a view to clarify the accumulation of inorganic and organic pollutants deriving from fuel exhausts on primary producers, the concentrations of Cu, Fe, Zn, phenanthrene and benzo[a]pyrene were determined in sediments and macrophytes collected from sites along the Cilento coast, in western Mediterranean Sea, characterized by different levels of anthropogenic pressures. The 18 species analysed, belonging to Cyanobacteria, Chlorophyta, Rhodophyta, Heterokontophyta and Embryophyta, exhibited different accumulation capabilities toward pollutants, with average concentrations of Cu, phenanthrene and benzo[a]pyrene in all the divisions (17.6 ± 2.3 μg g−1 d.w., 34.3 ± 2.1 ng g−1 d.w., 61.5 ± 9.4 ng g−1 d.w., respectively) higher than those measured in sediments (4.0 ± 0.7 μg g−1 d.w., 11.6 ± 0.9 ng g−1 d.w., 14.8 ± 1.0 ng g−1 d.w., respectively) and more than one order of magnitude higher in Embryophyta for Cu (62.9 ± 7.1 μg g−1 d.w.) and in Cyanobacteria for benzo[a]pyrene (181 ± 2 ng g−1 d.w.). The obtained findings constitute a reference for the accumulation capabilities of different taxa and for the behaviour of different fuel exhaust pollutants in marine coastal environments, with implication for their transfer across trophic webs.

Ecologically Oriented Freeway Control Methods Integrated Speed Limits and Ramp Toll Booths Layout

Traffic exhaust pollution, especially in congested areas of freeways, is one of the main causes of air pollution. With the increase in the number of vehicles, traffic and environmental issues have become more prominent. In addition, traffic congestion leads to frequent starting and stopping of vehicles, further exacerbating environmental pollution. This article focuses on the problem of frequent starting and stopping of vehicles, using variable speed limit control to smooth traffic flow, reduce vehicle speed, and alleviate exhaust emissions caused by traffic congestion. At the same time, considering the traffic and environmental benefits of bottleneck areas on freeways, the VT-Micro model is used to calculate exhaust emissions, and a coordinated control method for the mainline and ramp of freeways is proposed. The simulation experiment results show that the total driving time of the mainline and ramp collaborative control method considering environmental benefits has been reduced by 24.69%, CO emissions have been reduced by 4.79%, HC emissions have been reduced by 7.65%, NOx emissions have been reduced by 2.48%, and fuel consumption has been reduced by 4.98%.

Hydrogen doping control method for gasoline engine acceleration transient air-fuel ratio

One of the primary contributors to automobile exhaust pollution is the significant deviation between the actual and theoretical air-fuel ratios during transient conditions, leading to a decrease in the conversion efficiency of three-way catalytic converters. Therefore, it becomes imperative to enhance fuel economy, reduce pollutant emissions, and improve the accuracy of transient control over air-fuel ratio (AFR) in order to mitigate automobile exhaust pollution. In this study, we propose a Linear Active Disturbance Rejection Control (LADRC) Hydrogen Doping Compensation Controller (HDC) to achieve precise control over the acceleration transient AFR of gasoline engines. By analyzing the dynamic effects of oil film and its impact on AFR, we establish a dynamic effect model for oil film and utilize hydrogen's exceptional auxiliary combustion characteristics as compensation for fuel loss. Comparative experimental results demonstrate that our proposed algorithm can rapidly regulate the AFR close to its ideal value under three different transient conditions while exhibiting superior anti-interference capability and effectively enhancing fuel economy.

Therapeutic Potential of Hydrogen Sulfide in Reproductive System Disorders.

Hydrogen sulfide (H2S), previously regarded as a toxic exhaust and atmospheric pollutant, has emerged as the third gaseous signaling molecule following nitric oxide (NO) and carbon monoxide (CO). Recent research has revealed significant biological effects of H2S in a variety of systems, such as the nervous, cardiovascular, and digestive systems. Additionally, H2S has been found to impact reproductive system function and may have therapeutic implications for reproductive disorders. This paper explores the relationship between H2S and male reproductive disorders, specifically erectile dysfunction, prostate cancer, male infertility, and testicular damage. Additionally, it examines the impact of H2S regulation on the pathophysiology of the female reproductive system, including improvements in preterm birth, endometriosis, pre-eclampsia, fetal growth restriction, unexplained recurrent spontaneous abortion, placental oxidative damage, embryo implantation, recovery of myometrium post-delivery, and ovulation. The study delves into the regulatory functions of H2S within the reproductive systems of both genders, including its impact on the NO/cGMP pathway, the activation of K+ channels, and the relaxation mechanism of the spongy smooth muscle through the ROCK pathway, aiming to broaden the scope of potential therapeutic strategies for treating reproductive system disorders in clinical settings.

Optimizing soybean biofuel blends for sustainable urban medium-duty commercial vehicles in India: an AI-driven approach

This article presents the outcomes of a research study focused on optimizing the performance of soybean biofuel blends derived from soybean seeds specifically for urban medium-duty commercial vehicles. The study took into consideration elements such as production capacity, economics and assumed engine characteristics. For the purpose of predicting performance, combustion and emission characteristics, an artificial intelligence approach that has been trained using experimental data is used. At full load, the brake thermal efficiency (BTE) dropped as engine speed increased for biofuel and diesel fuel mixes, but brake-specific fuel consumption (BSFC) increased. The BSFC increased by 11.9% when diesel compared to using biofuel with diesel blends. The mixes cut both maximum cylinder pressure and NOx\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${{\ ext{NO}}}_{{\ ext{x}}}$$\\end{document} emissions. The biofuel-diesel fuel proved more successful, with maximum reduction of 9.8% and 22.2 at rpm, respectively. The biofuel and diesel blend significantly improved carbon dioxide (CO2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${{\ ext{CO}}}_{2}$$\\end{document}) and smoke emissions. The biofuel blends offer significant advantages by decreeing exhaust pollutants and enhancing engine performance.Graphical

Aerodynamic design optimization of locally built FSR Isuzu bus through numerical simulation

Reducing the fuel consumption of commercial vehicles—especially those used for public transportation—has become increasingly important due to advancements in the automotive industry. On the other hand, the main disadvantages of buses and other commercial vehicles are their fuel consumption, exhaust pollutants, and crosswind stability. Most buses built in Ethiopia have aerodynamic rectangular shapes and strong drag resistance forces, which lead to higher fuel consumption. One of the most accessible buses in Ethiopia is the FSR Isuzu Bus; its external body is locally constructed and has a poor aerodynamic shape. The primary goal of this study is to reduce aerodynamic drag force by improving the outer body shape of the current FSR Isuzu Bus. It also aims to examine the impact of roughness (strip) on the overall aerodynamic characteristics of the bus when it encounters crosswinds, thereby reducing fuel consumption, roll moment, and side force. For computational fluid dynamics (CFD) analysis, ANSYS Fluent is used, and Solidwork is used to model the bus body. A comparison is made between the current CFD analysis of the bus body and the modified design at varying speeds. Three separate models are used in the analysis. At an average speed of 100 kmph, 29.58% (4 to 5 liters) of fuel can be saved, and the drag force is reduced by roughly 49.7% when comparing the new concept to the current bus. By utilizing a strip on the bus’s roof, the side force coefficient and the roll moment coefficient are subsequently reduced from model two to model three by 8.76% and 9.01%, respectively. The study’s conclusions indicate that the external body shape changes have reduced drag; and, adding roof strips has decreased drag to acceptable level and enhanced crosswind stability.

New perspective of environmental impact research: predicting bus exhaust emissions using the ETSformer based on collaborative perception

Accurate prediction of urban traffic exhaust emissions plays a crucial role in controlling motor vehicle exhaust pollution. Urban public transport vehicles often operate in stop-and-go traffic conditions, emitting significant exhaust pollution. Existing approaches primarily focus on assessing vehicle emissions in the past or present, which may not adequately address long-term planning needs. To enhance the accuracy of bus exhaust emissions prediction, we introduce a novel time series transformer architecture named ETSformer for forecasting future vehicle emissions. This framework integrates exponential smoothing principles to refine the transformer-based time series prediction model, utilizing historical pollutant emissions data to forecast future exhaust emissions. The experiment collects emissions data and driving status information from public transport vehicles in Zhenjiang City, Jiangsu Province, considering factors such as vehicle runtime, route, and operational state to standardize response variables and enhance model precision and consistency. Experimental results demonstrate a determination coefficient (R2) of 70.7% and a mean square error (MSE) of 41.1% for exhaust gas prediction, signifying improved accuracy and efficiency compared to other models. Applying the exhaust gas prediction model to bus operations enables advanced forecasting of future exhaust emissions, addressing current challenges and potentially reducing Carbon Dioxide (CO2) emissions by over 3% during bus operations.

Neuroimmune recognition and regulation in the respiratory system.

Neuroimmune recognition and regulation in the respiratory system is a complex and highly coordinated process involving interactions between the nervous and immune systems to detect and respond to pathogens, pollutants and other potential hazards in the respiratory tract. This interaction helps maintain the health and integrity of the respiratory system. Therefore, understanding the complex interactions between the respiratory nervous system and immune system is critical to maintaining lung health and developing treatments for respiratory diseases. In this review, we summarise the projection distribution of different types of neurons (trigeminal nerve, glossopharyngeal nerve, vagus nerve, spinal dorsal root nerve, sympathetic nerve) in the respiratory tract. We also introduce several types of cells in the respiratory epithelium that closely interact with nerves (pulmonary neuroendocrine cells, brush cells, solitary chemosensory cells and tastebuds). These cells are primarily located at key positions in the respiratory tract, where nerves project to them, forming neuroepithelial recognition units, thus enhancing the ability of neural recognition. Furthermore, we summarise the roles played by these different neurons in sensing or responding to specific pathogens (influenza, severe acute respiratory syndrome coronavirus 2, respiratory syncytial virus, human metapneumovirus, herpes viruses, Sendai parainfluenza virus, Mycobacterium tuberculosis, Pseudomonas aeruginosa, Staphylococcus aureus, amoebae), allergens, atmospheric pollutants (smoking, exhaust pollution), and their potential roles in regulating interactions among different pathogens. We also summarise the prospects of bioelectronic medicine as a third therapeutic approach following drugs and surgery, as well as the potential mechanisms of meditation breathing as an adjunct therapy.

Thermographic Analysis of Exhaust Gas and Emissions by Varying Catalyst Behaviour and Injection Parameters

This study focuses on the detailed analysis of exhaust emissions from multi-point fuel injection (MPFI) engines by manipulating the injection parameters through a programmable electronic control unit. In addition, tests are carried out using different generations of catalytic converters and checking that their working temperature is correct using a thermographic camera, verifying operation, to evaluate their effect on emission reduction. Detailed comparisons of the results between these configurations will allow the identification of the combination that reduces emissions the most without compromising engine efficiency and performance. This research aims to promote a more sustainable approach in the automotive sector by properly configuring systems, but also by demonstrating the technical robustness of their application in vehicles. It has also helped to verify that varying injection and ignition parameters help to fine-tune fuel injection, resulting in efficient combustion. Combining this variation with catalytic converters has further reduced exhaust pollutants.

Energy, exergy and sustainability analyses of nanoparticles added to fuels to reduce carbon footprint

In this study, experimental and thermodynamic analyses were used to investigate the use of fuel blends created by adding cerium oxide (CeO2) and aluminium oxide (Al2O3) nanoparticles to diesel/heavy fuel oil (HFO) fuel blends in a compression ignition engine. In the study, a single-cylinder compression ignition engine was tested at four different engine loads at a constant engine speed of 3000 rpm. The experiments measured engine power, fuel consumption, exhaust gas temperature, engine casing temperature and exhaust pollutants. Thus, a study on energy, efficiency and sustainability was carried out by comparing fuel blends. All fuel blends were subjected to energy and exergy efficiency, lost exergy and sustainability index calculations. The addition of nanoparticles to the fuel increases the energy loss compared to the D80F20 (80% Diesel + 20% HFO) fuel blend. Comparing D80F20AL100 (80% Diesel + 20% HFO + 100 ppm Al2O3) and D80F20CE100 (80% Diesel + 20% HFO + 100 ppm CeO2) fuel blends, the exergy loss of D80F20 fuel is 10.76% and 14.23% higher when the engine power is 4000 W, respectively. The energy efficiency of D80F20 fuel increases as more nanoparticles are added and reaches 12.60% and 12.80% for D80F20CE25 (80% Diesel + 20%HFO + 25 ppm CeO2) and D80F20CE100 fuels under 3000 W engine load, respectively. The inclusion of nanoparticles in diesel/HFO fuel blends gives results in line with the sustainability index.

Subacute Exposure to Gaseous Pollutants from Diesel Engine Exhaust Attenuates Capsaicin-Induced Cardio-Pulmonary Reflex Responses Involving Oxidant Stress Mechanisms in Adult Wistar Rats.

Intravenous injection of capsaicin produces vagal-mediated protective cardio-pulmonary (CP) reflexes manifesting as tachypnea, bradycardia, and triphasic blood pressure (BP) response in anesthetized rats. Particulate matter from diesel engine exhaust has been reported to attenuate these reflexes. However, the effects of gaseous constituents of diesel exhaust are not known. Therefore, the present study was designed to investigate the effects of gaseous pollutants in diesel exhaust, on capsaicin-induced CP reflexes in rat model. Adult male rats were randomly assigned to three groups: Non-exposed (NE) group, filtered diesel exhaust-exposed (FDE) group and N-acetyl cysteine (NAC)-treated FDE group. FDE group of rats (n = 6) were exposed to filtered diesel exhaust for 5 h a day for 5days (D1-D5), and were taken for dissection on day 6 (D6), while NE group of rats (n = 6) remained unexposed. On D6, rats were anesthetized, following which jugular vein was cannulated for injection of chemicals, and femoral artery was cannulated to record the BP. Lead II electrocardiogram and respiratory movements were also recorded. Results show that intravenous injection of capsaicin (0.1ml; 10µg/kg) produced immediate tachypneic, hyperventilatory, hypotensive, and bradycardiac responses in both NE and FDE groups of rats. However, these capsaicin-induced CP responses were significantly attenuated in FDE group as compared to the NE group of rats. Further, FDE-induced attenuation of capsaicin-evoked CP responses were diminished in the N-acetyl cysteine-treated FDE rats. These findings demonstrate that oxidant stress mechanisms could possibly be involved in inhibition of CP reflexes by gaseous pollutants in diesel engine exhaust.

Applications of Electric Heating Technology in Vehicle Exhaust Pollution Control

Motor vehicle exhaust is an important cause of atmospheric pollution. Nowadays, mainstream exhaust emission aftertreatment technologies, such as TWC, DOC, SCR, and DPF, usually require sufficient temperature to perform good purification or maintain normal working conditions. Compared with exhaust gas heating technologies such as engine enrichment and fuel injection, electric heating technology can quickly increase the temperature of exhaust gas aftertreatment devices without adverse effects on engine operating conditions. This article introduces the research and progress of electric heating technology combined with traditional aftertreatment devices on major types of vehicles, such as gasoline vehicles, diesel vehicles, motorcycles, and hybrid vehicles, to improve exhaust purification efficiency and its accompanying fuel consumption impact. In addition, the common structure and characteristics of electric heaters, as well as the current status and development trend of electric heating unit technologies such as electric heating power supply are introduced.

Formation of atmospheric molecular clusters containing nitric acid with ammonia, methylamine, and dimethylamine.

This study investigates the formation of atmospheric molecular clusters containing ammonia (NH3, A), methylamine (CH3NH2, MA), or dimethylamine (CH3NHCH3, DMA) with nitric acid (HNO3, NA) using quantum mechanics. The Atmospheric Cluster Dynamic Code (ACDC) was employed to simulate the total evaporation rate, formation rate, and growth pathways of three types of clusters under dry and hydrated conditions. This study evaluates the enhancing potential of A/MA/DMA for NA-based new particle formation (NPF) at parts per trillion (ppt) levels. The results indicate that A/MA/DMA can enhance NA-based NPF at high nitric acid concentrations and low temperatures in the atmosphere. The enhancing potential of MA is weaker than that of DMA but stronger than that of A. Cluster growth predominantly follows the lowest free energy pathways on the acid-base grid, with the formation of initial acid-base dimers (NA)(A), (NA)(MA), and (NA)(DMA) being crucial. Hydration influences the evaporation rate and formation rate of clusters, especially for initial clusters. When the humidity is at 100%, the formation rate for NA-A, NA-MA, and NA-DMA clusters can increase by approximately 109, 107, and 104-fold compared to the corresponding unhydrated clusters, respectively. These results highlight the significance of nitric acid nucleation in NPF events in low-temperature, high-humidity atmospheres, particularly in regions like China with significant automobile exhaust pollution.

Experimental Analysis of Diesel Engine Performance and Emissions with the Integration of Cyclonic Separator Device

The high population density and demographic dynamics have triggered a boom in the uptake of larger and more fuel-efficient diesel goods vehicles because diesel is cheaper than gasoline. Nevertheless, availability of diesel engines has lead to an increase of pollution especially in the urban area. This research examines whether a cyclonic separator which is an attachment device mounted on the vehicle exhaust system can sufficiently reduce particulate emissions from diesel engines. Thanks, the cyclonic separator is used to gather particles of size from 1μm to 50μm, to control the emission of diesel exhaust pollutants. Although we find that the utilization of the device decreases the pollution emission, our study shows that the installation of the device causes backpressure leading to a marginal reduction in thermal efficiency of between 0.8% to 1.01%. Nevertheless, the cyclonic separator can be considered one of the possible means to solve the problem of reduction of emissions of diesel engines and protect urban environment from pollution.