Diesel Exhaust Particles Research Articles

Advancements in cobalt‐based oxide catalysts for soot oxidation: Enhancing catalytic performance through modification and morphology control

AbstractThe widespread use of diesel engines results in significant environmental contamination due to emitted pollutants, particularly soot particles. These pollutants are detrimental to public health. At present, one of the most effective ways to remove soot particles is the catalytic diesel particulate filter after‐treatment technology, which requires the catalyst to have superior low temperature activity. Compared with cerium oxide which is widely used, cobalt oxide in transition metal oxides has been widely studied in recent years because of its high redox ability and easy to control morphology. This paper elaborates on the influence of modification techniques such as doping, loading, and solid solution on the catalytic performance of cobalt‐based catalysts in soot oxidation. Along the same lines, it further reviews the research progress on cobalt‐based oxide catalysts with specific dimensional structures and morphologies in soot oxidation. Finally, it provides an outlook on the challenges faced by the theoretical basis and applied research of cobalt‐based catalysts in soot oxidation.

Diesel exhaust particles activate macrophages and IRF5 expression in atherosclerosis

Abstract Introduction Over 20% of global deaths related to cardiovascular disease have been attributed in part to air pollution, particularly fine particulate matter (PM2.5) (1). In highly trafficked urban areas, smaller ultrafine diesel exhaust particles (DEP) represent a significant proportion of PM2.5. DEP is associated with the progression of atherosclerosis and increased plaque susceptibility to rupture (2). We have previously shown that interferon regulatory factor 5 (IRF5) has a key role in necrotic core formation, a distinguishing feature of vulnerable atherosclerotic plaques, by rendering macrophages defective at efferocytosis (3). Pronounced elevation of IRF5 is also seen in symptomatic carotid plaques, particularly in the rupture-prone shoulder regions (4). Purpose We examined the effect of DEP on macrophage phenotype and IRF5 expression in atherosclerosis. Methods Bone marrow-derived macrophages (BMDMs) from C57BL/6 mice, differentiated with GM-CSF (to mimic inflammatory macrophages) or M-CSF (mimicking homeostatic resident macrophages) were incubated with PBS or DEP (10 µg/mL) in vitro for 18 hours. Expression of inflammatory cytokines (IL-6, IL-12α), macrophage polarisation markers CD11c (itgax, inflammatory) and CD206 (mrc1, resident anti-inflammatory) and IRF5 was quantified by real-time PCR. In addition, high fat-fed ApoE-/- mice were exposed to saline or DEP (35 µL at 1 mg/mL) twice weekly for 5 weeks by pulmonary administration. The pan-macrophage marker CD64, CD206 and IRF5 were quantified in paraffin-embedded sections of brachiocephalic artery lesions by immunohistochemistry. Results In M-CSF-differentiated murine macrophages incubated with DEP, significant fold increases in gene expression (relative to PBS control) were observed: IRF5 (1.4-fold), IL-6 (31.5-fold) and IL-12α (5.8-fold) while CD206 (0.8-fold) decreased (Figure 1a, n = 5, p<0.05, two-tailed paired t-tests). CD11c expression was unchanged. No statistically significant differences were detected in GM-CSF-differentiated macrophages. In the brachiocephalic arteries of DEP-exposed ApoE-/- mice we observed increases in CD64+ macrophages (28.2±7.4 vs 15.5±5.6) and IRF5 (16.6±3.6 vs 10.1±3.4) expression, while CD206 expression decreased (4.1±0.9 vs 11.0±1.2) in comparison to saline-exposed mice (Figure 1b mean±SD, n = 5, p<0.05, two-tailed unpaired t-tests, data expressed as % of intima area). Conclusion DEP promotes CD64+ macrophages and IRF5 expression in murine atherosclerosis, while inflammation and IRF5 is induced in vitro, but only in M-CSF-differentiated murine BMDMs. This suggests that DEP has no impact on inflammatory macrophages but could switch homeostatic resident macrophages to a more inflammatory phenotype via the activation of IRF5. Therefore, IRF5 is a promising candidate for further investigation into the initial macrophage response to inhaled particles that leads to the exacerbation of vascular disease.

Progranulin derivative attenuates lung neutrophilic infiltration from diesel exhaust particle exposure.

Air pollutants, such as diesel exhaust particles (DEPs), induce respiratory disease exacerbation with neutrophilic infiltration. Progranulin (PGRN), an epithelial cell and macrophage-derived secretory protein, is associated with neutrophilic inflammation. PGRN is digested into various derivatives at inflammatory sites and is involved in several inflammatory processes. PGRN and its derivatives likely regulate responses to DEP exposure in allergic airway inflammation. To investigate the role of PGRN and its derivatives in the regulation of responses to DEP exposure in allergic airway inflammation. A murine model of allergic airway inflammation was generated in PGRN-deficient mice, and they were simultaneously exposed to DEP followed by intranasal administration of full-length recombinant PGRN (PGRN-FL) and a PGRN-derived fragment (FBAC). Inflammatory status was evaluated by bronchoalveolar lavage fluid and histopathologic analyses. Human bronchial epithelial cells were stimulated with DEPs and house dust mites (HDMs), and the effect of FBAC treatment was evaluated by assessing various intracellular signaling molecules, autophagy markers, inflammatory cytokines, and intracellular oxidative stress. DEP exposure exaggerated neutrophilic inflammation, enhanced IL-6 and CXCL15 secretions, and increased oxidative stress in the murine model; this effect was greater in PGRN-deficient mice than in wild-type mice. The DEP-exposed mice with PGRN-FL treatment revealed no change in neutrophil infiltration and higher oxidative stress status in the lungs. On the contrary, FBAC administration inhibited neutrophilic infiltration and reduced oxidative stress. In human bronchial epithelial cells, DEP and HDM exposure increased intracellular oxidative stress and IL-6 and IL-8 secretion. Decreased nuclear factor erythroid 2-related factor 2 (Nrf2) expression and increased phosphor-p62 and LC3B expression were also observed. FBAC treatment attenuated oxidative stress from DEP and HDM exposure. FBAC reduced neutrophilic inflammation exaggerated by DEP exposure in a mouse model of allergic airway inflammation by reducing oxidative stress. PGRN and PGRN-derived proteins may be novel therapeutic agents in attenuating asthma exacerbation induced by air pollutant exposure.

Particle Size and Morphological Evaluation of Airborne Urban Dust Particles by Scanning Electron Microscopy and Bidimensional Empirical Mode Analysis

Airborne particles affect the health of the population. As particles decrease in size, they can penetrate deeper into the respiratory system, reaching the terminal bronchioles and alveoli. Particles as small as 0.1 µm in diameter may translocate into the bloodstream, potentially impacting various organs. Additionally, the smaller the particle size, the longer they remain suspended in the air, thereby increasing their deleterious damages. The aim of this work is to study the size distribution of airborne particles emitted from anthropogenic sources of air pollution, with a special emphasis on estimating the distribution of micro and nanoparticles considered the most harmful to health. The Bidimensional Empirical Mode Decomposition (BEMD) algorithm was used on micrographs of the particles obtained by Scanning Electron Microscopy (SEM). BEMD is a current empirical computational tool applied to image analysis that allows extracting non-linear heterogeneous oscillations of brightness. We studied ROFA (Residual Oil Fly Ash) from industrial sources and DEP (Diesel Exhaust Particles) from vehicular emissions as airborne particles. After collecting the particles on filters, micrographs were taken using SEM at different magnifications to which the BEMD algorithm was applied. Particle size and asymmetry distributions were obtained for each mode, allowing the identification of the most deleterious particles. The methodology employed herein is relatively simple and effective for inferring the impact of airborne particulate matter on health and the environment.

The Toxic Effects of Petroleum Diesel, Biodiesel, and Renewable Diesel Exhaust Particles on Human Alveolar Epithelial Cells.

The use of alternative diesel fuels has increased due to the demand for renewable energy sources. There is limited knowledge regarding the potential health effects caused by exhaust emissions from biodiesel- and renewable diesel-fueled engines. This study investigates the toxic effects of particulate matter (PM) emissions from a diesel engine powered by conventional petroleum diesel fuel (SD10) and two biodiesel and renewable diesel fuels in vitro. The fuels used were rapeseed methyl ester (RME), soy methyl ester (SME), and Hydrogenated Vegetable Oil (HVO), either pure or as 50% blends with SD10. Additionally, a 5% RME blend was also used. The highest concentration of polycyclic aromatic hydrocarbon emissions and elemental carbon (EC) was found in conventional diesel and the 5% RME blend. HVO PM samples also exhibited a high amount of EC. A dose-dependent genotoxic response was detected with PM from SD10, pure SME, and RME as well as their blends. Reactive oxygen species levels were several times higher in cells exposed to PM from SD10, pure HVO, and especially the 5% RME blend. Apoptotic cell death was observed in cells exposed to PM from SD10, 5% RME blend, the 50% SME blend, and HVO samples. In conclusion, all diesel PM samples, including biodiesel and renewable diesel fuels, exhibited toxicity.

An experimental study about the characteristics of reciprocating flow regeneration of diesel particulate filter with diesel vapor injection

To strengthen the practicality of the periodic reciprocating flow (PRF)regeneration of diesel particulate filter (DPF), a compact structure of PRF-DPF system with diesel vapor injection is developed. An experimental study is carried out about the regeneration characteristics of the PRF-DPF system. The results show that U-type passage structure can form a new heat recovery mechanism of PRF through internal heat conduction, in which a temperature fluctuation cycle within each forward flow or backward flow is formed; the complete oxidation of HCs can be achieved as a diesel vaporizer be installed at about 330 mm in front of the entrance end of DPF catalyzer, and the wider middle region can be kept at 400–520 °C through supplying 5.0 ml/min −20# diesel vapor at a 12.4 kW engine load; As injected 7.0 ml/min −10# diesel vapor at a 11.8 kW engine load, the PRF can provide the simultaneous process conditions of C-NO2, C–NO2–O2 and C-O2 reactions and remove particulate matter (PM), thus and the filtration efficiency of PM can be higher than 99 %.

Impact of Design Dimension Optimization on Capacitive Sensor Performance for Particulate Matter Detection and Measurement

Particulate matter (PM) emissions from exhaust gases are major pollutants and cause serious health problems. Diesel particulate filters (DPF) are used for monitoring and trapping particulates from exhaust gases. For sensing these particulates sensors are used downstream of a DPF. The present study proposes an interdigitated electrode (IDE) capacitive sensor for detecting and measuring deposited particulates on the sensor surface. The sensor dimensions are optimized to detect and measure the least deposition of particulates. The paper presents improvement in sensor performance, a high selectivity of 65.70% with an accuracy of 87.26%. Dimension optimization extracts capacitance of 581 pF manifolds 10 times more than the reference sensor from the literature. The study presents a sensor with a thin sensing layer manufactured by optical lithography and a lift-off method for IDE. Measurements and testing showed that the sensor measures the lowest particulate mass of 0.0045 mg in 3.4 ms

Investigation of diesel particulate filter performance under typical failure conditions

Diesel particulate filter (DPF) is one of the most effective particulate reduction components in diesel engine aftertreatment systems. However, prolonged utilization of a DPF might result in a deterioration in performance or even failure, such as ash-clogging, melting, breakage, and catalyst deactivation. It is crucial to conduct research on DPF performance degradation across a series of partially failed conditions. In this study, the morphology and chemical composition of the ash in the DPF samples were characterized. The effects of degree-varying clogging and unplugged-breakage failure on exhaust characteristics as well as DPF temperature, filtration and pressure drop characteristics were investigated. Finally, the sensitivity differences between DPF performance parameters and failure index parameters were examined using a canonical correlation analysis (CCA). When four factors were considered, the ash loading index and breakage index had the greatest impact on DPF temperature difference and filtration efficiency, while the exhaust mass flow rate had the greatest impact on pressure drop. Besides, the influence of the DPF inlet temperature on the pressure drop, filtration efficiency, and temperature difference was not significant. These findings contribute to the prediction of DPF performance in partially failed conditions and the development of DPF failure diagnosis methods.

Optimal Control of Hydrocarbon Reducer (HC) Injection Based on Trust-Region-Reflective Algorithm (TRRA) and Physical Models for Diesel Oxidation Catalyst (DOC)

The aim of this paper is to control the DOC outlet gas temperature between 600±15°C by optimizing the hydrocarbon (HC) injection into the Diesel Oxidation Catalyst (DOC) for active regeneration of the downstream Diesel Particulate Filter (DPF). First, based on the physical model of the DOCthermal dynamics, the energy conservation equation for the gas phase temperature is simplified by using variable substitution, and the energy conservation equation for the solid phase temperature is simplified by considering only the heat generated by the HC injection. By solving the simplified model using the Trapezoidal Rule-Backward Differentiation Formula 2 (TR-BDF2) method and optimizing the model parameters in combination with the Gauss-Newton method, the computational efficiency and accuracy were significantly improved. Next, the DOC downstream temperature observer is designed by combining the solution characteristics of the DOC model with the unscented Kalman filter (UKF) algorithm to ensure that the catalyst operates within the optimal temperature range. Then, this paper verifies the accuracy of the model and observer through bench tests covering four steady-state operation conditions and World Harmonized Transient Cycle (WHTC)test cycle, and the results show that the model and observer exhibit high accuracy in both steady-state and transient operation conditions. Finally, the DOC temperature was successfully maintained between 600±15°C by optimizing the control of the HC injectionrate, thus achieving the expected temperature control target. These research results provide theoretical and practical support for diesel engine emission control and DPF active regeneration.

Migration of Platinum Nanoparticles via Volatile Platinum Dioxide during Lean High-Temperature Ageing of Diesel Oxidation Catalysts

When platinum-containing diesel oxidation catalysts (DOC) are exposed to high temperatures under lean conditions, the platinum nanoparticles form volatile platinum dioxide on the catalyst surface. The exhaust flow carries the volatile platinum dioxide to the downstream aftertreatment catalyst, such as the selective catalytic reduction (SCR) catalyst, that is responsible for reducing the nitrogen oxides (NOx) emissions and can negatively impact its performance, by promoting the parasitic oxidation of ammonia. Here we investigate the factors such as exposure time, temperature and DOC design characteristics for their impact on the platinum dioxide migration, by characterising the amount of platinum deposited on the SCR catalyst at very low levels (<5 ppm), using inductively coupled plasma optical emission spectroscopy (ICP-OES) fire assay technique. Our results indicate that well-dispersed platinum, not associated with palladium, is most prone to platinum dioxide migration. We also compare several methods to suppress the platinum dioxide migration from the DOC, such as sintering of the platinum nanoparticles, stabilising the platinum nanoparticles via interaction with palladium or covering the platinum nanoparticles with a high surface area capture layer to trap the volatile platinum dioxide.

Exploring ultrafine particle emission characteristics from in-use light-duty diesel trucks in China using a portable measurement system

Diesel vehicle exhaust is one of the major contributors to ultrafine particles (UFPs) in urban areas in China. However, there is still a lack of knowledge about UFPs emission characteristics from current in-use diesel vehicles. This study has carried out an on-road test of 10 in-use Light-duty Diesel Trucks (LDDTs) with different emission control standards in China using a self-established portable measurement system based on the Electronic Low-pressure Impactor (ELPI) and characterized the ultrafine particle number (PN) concentration, particle size distribution and metal element contents. The results revealed a significant reduction of 93.37% in the average PN0.1 emission factor of LDDTs from China IV to China VI. Notably, LDDTs compliant with the China VI vehicle emission control standard exhibited the lowest PN0.1 and PM0.1 emission factors, measuring 4.991×1014 #/km and 0.627 g/km, respectively. By taking into account emissions under real driving conditions, we found that the PN emission rates grow with the increase of the Vehicle Specific Power (VSP). The cold-start phase had higher PN emissions than the hot-start phase, with 8590, 1890, 477, and 22 times higher than those of the ambient air (1.18×105 #/cm3), respectively. The installation of Diesel Particulate Filter (DPF) can decrease UFPs by more than 99.8%, while the PN emission factor during the DPF regeneration stage (1.85×1016 #/km) increased by 5 orders of magnitude that of the DPF normal works (7.51×1011 #/km). Metal element contents analysis shows that Fe, Ca, Al and Mg are the dominant elements in UFPs of LDDT exhaust gas, but the element of Ni is slightly increasing in a China VI, possibly due to the new automotive engine exhaust manifolds being made of Ni instead of cast iron for the purpose of having more high-temperature resistance. Our study demonstrates the importance of monitoring and routine maintenance of exhaust after-treatment systems.

Diesel exhaust particle inhalation in conjunction with high-fat diet consumption alters the expression of pulmonary SARS-COV-2 infection pathways, which is mitigated by probiotic treatment in C57BL/6 male mice

BackgroundBoth exposure to air pollutants and obesity are associated with increased incidence and severity of COVID-19 infection; however, the mechanistic pathways involved are not well-characterized. After being primed by the transmembrane protease serine 2 (TMPRSS2) or furin protease, SARS-CoV-2 uses the angiotensin-converting enzyme (ACE)-2 receptor to enter respiratory epithelial cells. The androgen receptor (AR) is known to regulate both TMPRSS2 and ACE2 expression, and neuropilin-1 (NRP1) is a proposed coreceptor for SARS-CoV-2; thus, altered expression of these factors may promote susceptibility to infection. As such, this study investigated the hypothesis that inhalational exposure to traffic-generated particulate matter (diesel exhaust particulate; DEP) increases the expression of those pathways that mediate SARS-CoV-2 infection and susceptibility, which is exacerbated by the consumption of a high-fat (HF) diet.MethodsFour- to six-week-old male C57BL/6 mice fed either regular chow or a HF diet (HF, 45% kcal from fat) were randomly assigned to be exposed via oropharyngeal aspiration to 35 µg DEP suspended in 35 µl 0.9% sterile saline or sterile saline only (control) twice a week for 30 days. Furthermore, as previous studies have shown that probiotic treatment can protect against exposure-related inflammatory outcomes in the lungs, a subset of study animals fed a HF diet were concurrently treated with 0.3 g/day Winclove Ecologic® Barrier probiotics in their drinking water throughout the study.ResultsOur results revealed that the expression of ACE2 protein increased with DEP exposure and that TMPRSS2, AR, NRP1, and furin protein expression increased with DEP exposure in conjunction with a HF diet. These DEP ± HF diet-mediated increases in expression were mitigated with probiotic treatment.ConclusionThese findings suggest that inhalational exposure to air pollutants in conjunction with the consumption of a HF diet contributes to a more susceptible lung environment to SARS-CoV-2 infection and that probiotic treatment could be beneficial as a preventative measure.

Assessment of Cytotoxicity and Genotoxicity Induced by Diesel Exhaust Particles (DEPs) on Cell Line A549 and the Potential Role of Amide-Functionalized Carbon Nanotubes as Fuel Additive

Epidemiological studies have consistently linked air pollution to severe health risks. One strategy to reduce the impact of combustion products from engines is adding additives to the fuel. Potential benefits have been observed in terms of performance and emissions, as well as in decreasing fuel consumption. However, the associated emission of particulate matter into the environment may have unforeseen health effects. This study examines the effects of diesel exhaust particles (DEPs) from diesel fuel mixed with amide-functionalized carbon nanotubes (CNTF). The aim is to analyze the properties of DEPs and determine their toxic effects on lung cells. The DEPs were characterized using scanning and transmission electron microscopy, while the polycyclic aromatic hydrocarbons (PAHs) were analyzed through gas chromatography. Various assays were conducted to assess cell viability, apoptosis, oxidative stress, and DNA damage. The addition of CNTF to diesel fuel altered the morphology and size of the particles, as well as the quantity and composition of PAHs. At the cellular level, diesel DEPs induce higher levels of reactive oxygen species (ROS) production, DNA damage, apoptosis, and cytotoxicity compared to both CNTF and diesel–CNTF DEPs. These findings suggest that the nano-additives enhance energy efficiency by reducing pollutants without significantly increasing cell toxicity.

Experimental and numerical analysis of particulate matter deposition in DPF for different blends of Algae Bio diesel

The stringent emission norms have compelled to use Diesel particulate filter (DPF) to reduce particulates emission in automotive Diesel engine. The back pressure developed in the DPF due to the Particulates matter (PM) deposition in porous zone degrades the diesel engine’s performance. So, there is a need of a fuel which should produce less particulates on combustion as well as its produced particulates should be easy to get regenerated inside the DPF. Three different Algae biodiesel blends B20, B40 and B60 were selected for the study, while the results are compared with the diesel fuel. A numerical study has been done with diesel and Algae biodiesel blends to investigate the effect of PM deposition on the DPF performance. The results of PM concentration and the pressure drop has been predicted for t = 2000s. and compared with the results predicted for diesel fuel. The summarized velocity contours and the PM concentration plots show that a maximum of the PM concentration was found in the diesel fuel case, while the lower found in B60 algae blend. Also, the pressure drop was found to increase with the increase in PM deposition in each case of fuel. The SEM-EDS analysis is done after collecting PM samples after combustion shows a higher percentage of Oxygen and lower Carbon with an increment of Biodiesel in the blend. This work provides a brief idea about the PM deposition in DPF while using Diesel and Algae Biodiesel blends and highlighting the better fuel option for Diesel Engine.

Exploring the dynamic evolution of lattice oxygen on exsolved-Mn2O3@SmMn2O5 interfaces for NO Oxidation

Lattice oxygen in metal oxides plays an important role in the reaction of diesel oxidation catalysts, but the atomic-level understanding of structural evolution during the catalytic process remains elusive. Here, we develop a Mn2O3/SmMn2O5 catalyst using a non-stoichiometric exsolution method to explore the roles of lattice oxygen in NO oxidation. The enhanced covalency of Mn–O bond and increased electron density at Mn3+ sites, induced by the interface between exsolved Mn2O3 and mullite, lead to the formation of highly active lattice oxygen adjacent to Mn3+ sites. Near-ambient pressure X-ray photoelectron and absorption spectroscopies show that the activated lattice oxygen enables reversible changes in Mn valence states and Mn-O bond covalency during redox cycles, reducing energy barriers for NO oxidation and promoting NO2 desorption via the cooperative Mars-van Krevelen mechanism. Therefore, the Mn2O3/SmMn2O5 exhibits higher NO oxidation activity and better resistance to hydrothermal aging compared to a commercial Pt/Al2O3 catalyst.

P07-10 Differential impact of renewable diesel exhaust particles on protein profiles in bronchoalveolar lavage fluid and plasma after instillation exposure in mice

P07-10 Differential impact of renewable diesel exhaust particles on protein profiles in bronchoalveolar lavage fluid and plasma after instillation exposure in mice

Effect of ash-bridge deposition in asymmetric diesel particulate filter channels on the pressure drop and particulate matter trapping characteristics

A diesel particulate filter (DPF) is commonly used to trap particulate matter (PM). The collapse and sintering of carbon and ash deposits during exhaust gas flow and DPF regeneration frequently result in the formation of ash bridges, which are buildups of ash and PM that clog the filter channels. To investigate the impact of an ash bridge formed by accumulated ash on the pressure drop and PM trapping characteristics of asymmetric DPFs, an asymmetric DPF channel with an ash bridge was constructed. The analysis employed computational fluid dynamics to examine how the ash bridge affects the pressure drop and PM trapping characteristics in an asymmetric DPF. This study reveals that the asymmetric DPF design effectively enhances the ash-holding capacity, thereby mitigating the risk of channel blockage. The presence of ash bridges in DPF channels has a more substantial impact on the pressure drop through radial congestion than through axial congestion. The application of asymmetric thin-wall DPFs can counteract the increase in exhaust backpressure caused by ash bridges. An ash bridge located in the middle of a DPF channel intensifies the uneven deposition of PM. However, implementing an asymmetric DPF structure enhances the uniformity of PM deposition.

Air pollution amyloidogenesis is attenuated by the gamma-secretase modulator GSM-15606.

Chronic air pollution (AirPoll) is associated with accelerated cognitive decline and risk of Alzheimer's disease (AD). Correspondingly, wild-type and AD-transgenic rodents exposed to AirPoll have increased amyloid peptides and behavioral impairments. We examined the γ-secretase modulator GSM-15606 for potential AirPoll protection by its attenuating of amyloid beta (Aβ)42 peptide production. Male and female wild-type mice were fed GSM-15606 during an 8-week inhalation exposure to AirPoll subfractions, ambient nanoparticulate matter (nPM), and diesel exhaust particles (DEP). GSM-15606 decreased Aβ42 during nPM and DEP exposure without changing beta- or gamma-secretase activity or BACE1 and PS1 protein levels. DEP increased lateral ventricle volume by 25%. These enzyme responses are relevant to AD drug treatments, as well as to the physiological functions of the Aβ42 peptide. GSM-15606 attenuation of Aβ42 may benefit human exposure to AirPoll. Gamma-secretase modulator (GSM-15606) attenuates the amyloidogenic amyloid beta (Aβ)42 peptide during exposure to air pollution, which may be a mechanism by which air pollution increases Alzheimer's disease (AD) risk. AD drug treatments may also consider Aβ homeostasis among the chronic effects of GSM-15606 and other amyloid reduction treatments on secretase enzymes.

Making of an Indigenous and Efficient Powertrains for EV, HEV & FCEV’s

Rise in greenhouse gas emissions which is resulting into ozone layer depletion and global warming effect is alarming to control CO2 emissions by drastically reducing fossil fuel consumption from the vehicles. This need has already started trend towards extreme downsizing and down speeding of Internal Combustion Engines (ICE) for making them highly efficient. In addition to this use of after treatment devices viz. Diesel Oxidation Catalyst (DOC), Diesel Particulate Filter (DPF), Lean NOx Catalyst (LNT), Selective Catalytic Reduction (SCR) are helping to a great extent for meeting emission norms till Euro - VI for automotive sector, Tier–IV F and Stage V for Off Highway Power sector. However, to address present greenhouse effect along with exponential decay of fossil fuels, there is need to achieve CO2 emissions less than 100 g/km or to achieve practically zero carbon footprint using an alternate powertrain. Electrification is one of the promising solutions and which is three-fold in present situation. The first level of electrification comes in the form of Hybrid Electric Vehicle (HEV) technology followed by Battery Electric Vehicles and Fuel Cell Electric Vehicles as second and third level of electrification respectively. In all these technologies a common thread is running in the form of an efficient electric drive train. Several efforts have been taken to improve torque per unit ampere by use of efficient motor and motor control algorithms viz PMSM powered with FOC, by developing controls which take care of parametric variations and external force disturbances by use of back stepping techniques which are based on rotor resistance estimation by fuzzy logic, FOC techniques based on adaptive input-output feedback linearization, by shifting towards high voltage systems, by going for higher switching frequencies for inverters which uses silicon carbide based MOSFET switches, by exploring use of multilevel inverters for Total Harmonic Distortion (THD) control etc. Use of E Axle based powertrains in EV, HEV and FCEV offers additional complimentary benefits apart from technology options described above. E Axle based powertrains offers flexibility in generating three variants of vehicle using one electric drive train architecture viz. making EV, HEV & FCEV. Compactness, modularity, scalability, flexibility along with efficient cooling system management and control over active current losses due to use of bus bars are the implicit advantages of E Axle based powertrains. These advantages further get multiplies if we go for 3 in 1 (gearbox + Stator housing + Inverter) architectures which are predominantly used in independent suspension-based vehicles. Lot of efforts are going on to inherit this technology for rigid axle suspension based commercial vehicles. Research in this area is getting further extended to make 5 in 1 E Axles where there will addition of DC - DC converter and On-Board Charger (OBC) apart from components present in 3 in 1 configuration. Two major challenges need to be addressed and to be resolved while designing E Axle based powertrains by doing concurrent vehicle engineering. This is mainly due to increased unsprang weight that need to be handled by suspension system and exposed electric drive components to excitation loads coming from roads. Fig: Indigenously Developed E Axle Based Powertrain for Small Commercial VehiclesBy proper lay outing for effective vehicle mass distribution and required CG location which is essential from overall vehicle dynamics, more space can be offered by E Axle based powertrains for increasing battery energy density for getting more electric range in case of BEV’s. This add on space benefit extend help in packaging of hydrogen fuel cell integrated with power cells in case of FCEV’s. Thus, E Axle based powertrains proves to be modern and most efficient way of making EV, HEV & FCEV’s.

Development of an Onboard Urea Electrolyser to Reduce NOx Emissions in Vehicles By Enhancing the Selective Catalytic Reduction with the Produced H2 and NH3

In the persistent pursuit of reducing nitrogen oxide emissions from diesel exhaust, challenges arise in achieving optimal performance at lower temperatures, especially in urban driving conditions. This research focuses on a pragmatic approach – development of an onboard urea electrolyser using diesel exhaust fluid (DEF) as the hydrogen-rich carrier. The primary goal is to enhance the NOx reduction efficiency at temperatures below 200oC by providing the electrolyser products – hydrogen and ammonia [1]. The reason behind this innovation lies in recognising DEF as a viable electrolyte, offering both safety and a promise of performance increase due to splitting of urea instead of water. Beyond the contribution to NOx reduction, this approach aligns with the broader societal and political imperatives of integrating cleaner energy solutions within the automotive sector. However, the development of a functional urea electrolyser involves certain complexities. The key considerations are the material stability under operating conditions, anode catalyst dissolution in DEF, mass transport limitations, and the reduction of relatively high cathode overpotentials. A notable aspect of our research involves addressing these challenges in scenarios both with and without potassium hydroxide alongside DEF, requiring a nuanced understanding of the electrochemical processes involved. Additionally, weight, packaging, and system integration play an important role in the development of an onboard urea electrolyser.This study systematically explores these challenges to devise a comprehensive understanding of the underlying electrochemical processes involved as well as the integration and operation strategy. The research methodology adopts single cell tests for which activation and measurement protocols have been established to achieve representative and comparable performance curve recordings and electrochemical impedance spectroscopy (EIS) data. Additionally, to various operating conditions of the electrolyte, the cell components screening adds to a considerable effort of this study. We explore the influence on the materials and design of the bipolar plates (BP) and porous transport layers (PTL); electrode performance and durability as well as the membrane selection. Within this study we consider anion exchange membranes (AEM) and bipolar membranes (BPM) for the performance comparison. Adopting both catalyst-coated membrane (CCM) and catalyst-coated substrate (CCS) approaches enables for examination of electrode preparation techniques and their influence on performance of the electrolysis cell. The initial results are promising, especially when employing 1 M KOH in the DEF electrolyte at 70oC, reaching 0.85 A cm-1 at 2 V. The respective performance curve is presented in Figure 1., together with a diagram of the electrolyser system integration into an existing Diesel exhaust line.This research represents a practical stride towards realising the denitrification of transportation sector especially in city cycle driving when the exhaust gases temperature is too low for the state-of-the-art SCR systems. By addressing identified challenges and optimising key parameters, our study lays a robust foundation for the scalable implementation of a functional urea electrolyser for transport applications and a basic understanding of the electrochemical processes behind the performance and stability of such a system.Figure 1.Depicts a recorded polarisation curve of a single cell using an anion exchange membrane (AEM) and nickel catalyst anode fed DEF and 1 M KOH as an electrolyte at 70oC. Below, the suggested integration of the electrolyser into latest generation Diesel exhaust aftertreatment system. It includes diesel oxidation catalyst (DOC), selective Diesel particulate filter (sDPF), hydrogen supported denitrification catalyst ‘H2-deNOx’ and finally a selective catalytic reduction (SCR) step.Reference: Esser, E., Kureti, S., Heckemüller, L., Todt, A. et al., "Low-Temperature NOx Reduction by H2 in Diesel Engine Exhaust," SAE Int. J. Adv. & Curr. Prac. in Mobility 4(5):1828-1845, 2022, https://doi.org/10.4271/2022-01-0538. Figure 1