Pollutant Emissions Research Articles

Kinetic insights and pollution mitigation in waste tire pyrolysis: Targeting sulfur, nitrogen, and PAHs emissions

Waste tires have potential to be used for generation of fuel via thermal degradation because of their non-biodegradable nature. Nevertheless, the formation of various pollutants such as sulfur-based and nitrogen-based are inevitable due to presence of nitrogen and sulfur containing compounds during waste tires production. The main purpose was to examine the effect of variating heating rates on pollutants release because heating rate is an important parameter which influences the pollutants releasing profile. Moreover, Ar and CO2 as reaction medium were used to identify their behavior for restraining the PAHs in gas phase. The present study investigates the influence of heating rates and carrier gas environment (Argon and CO2) to reduce the pollutants emission. Thermogravimetry-Mass Spectrum coupled with Fourier transform infrared spectrometer was used to evaluate the thermal degradation and pollutants formation. The major degradation of waste tires occurred between 300 and 500 ℃. The sulfur-based (H2S, CS2, COS, SO2, and CH3SH), nitrogen-based (NH3, HNCO, NO, and HCN) and 9 series of PAHs pollutants were detected. The higher heating rates promoted the pollutants emission. The degradation of compounds having sulfur content formed -SH radials and -SH helped in further release of sulfur based-pollutants. The NH3 releasing profile started after 200 ℃ and released till around 800 ℃ for 30 ⁰C/min and 40 ⁰C/min but its emission was very low after 600 ⁰C for heating rates 5 ⁰C/min, 10 ⁰C/min, and 20 ⁰C/min. The aromatic compounds fraction was more at higher heating rate due to short residence time for pyrolytic products to go through secondary reaction. The 5 ℃/min and 10 ℃/min were considered favorable heating rates in terms of achieving lowest activation energy in both gas environments. The thermodynamic parameters analysis suggested that waste tires pyrolysis was non-spontaneous and endothermic reaction as well as feedstocks showed potential to be utilized for waste conversion.

Governance and Sustainability in Developing Countries: Intelectual Structure, Trends and Lessons From Brazil and China

Objective: The purpose of this research is to analyze the intellectual structure and existing interconnections between governance and sustainability in developing nations, examining the prevailing trends and emerging topics. Additionally, the study compares Brazil and China, which are two of the most significant and diverse developing countries globally, with the goal of elucidating specific differences. This comparison aims to exemplify the similarities and disparities concerning sustainability and governance in these contexts. Method: A mixed-methods approach through a systematic literature review to build the intelectual strucrure, with the use of the bibliometrix package in R software, and descriptive statistics and t-tests were employed with the World Bank Data to profile some aspects and compare both countries. Results: Results bring evidence of a main interests related to governance impact and determinants, poluent emissions, corporate responsability and organization/country performance, within the literature. The study also suggets an inverse profile regarding governance and sustainability, with Brazil pointing to better sustainable conditions than China, however, with lesser business aspects to leverage development. Originality: The study on governance and sustainability in developing countries stands out for its detailed analysis of governance factors affecting pollutant emissions and corporate responsibility. The study also performs a specific comparison between Brazil and China, in terms of sustainable development aspects. Theoretical contributions: The study highlights a growing academic interest in governance and sustainability in developing countries, broadens the discourse to include key issues like pollutant emissions and corporate responsibility and country performance in terms o patent registration.

Towards sustainable development goals: An analysis of environmental efficiency and the impacts of self-purification capacity across diverse income levels

The increasing urgency of global environmental degradation, particularly across diverse economic development stages, underscores a critical need for nuanced understanding and targeted strategies to achieve Sustainable Development Goals. Our study examines environmental efficiency trends over 27 years in 163 countries, utilizing greenhouse gases and particulate matter 2.5 as indicators. We address the challenge by developing and applying a two-stage method that combines a hyperbolic distance function with a stochastic meta frontier approach to assess environmental meta-efficiency. The average meta efficiency of these countries is 0.464, which remains at a relatively low level. Our model indicates that the high-income country group needs to reduce greenhouse gas and pollutant emissions by 25% and increase non-fossil energy usage by 33% to improve environmental efficiency. This suggests these countries must transition towards more sustainable energy sources and practices. Moreover, recognizing that existing income grouping inadequately characterizes each country, we use k-means cluster analysis for regrouping, more accurately reflecting individual differences. The regrouping results show that some high-income countries are classified into inactive groups, implying serious environmental problems. Our findings advocate for collaborative and tailored strategies to address these disparities. We conclude that income levels cannot solely drive environmental efficiency but must also consider geographical and climatic factors, which are pivotal in shaping a country’s environmental policies and efforts. This approach offers a clearer understanding of current inefficiencies and sets the stage for more informed policy-making that can better address the specific needs and capabilities of different countries.

Mitigating policies for pollutant emissions in a DSGE for the Brazilian economy

This paper examines the dynamic behavior of the Brazilian economy under policy regimes aimed at controlling pollutant emissions and limiting environmental damage. Greenhouse gas (GHG) emissions are assumed to be of two types: carbon from fossil resources burning for energy generation (i.e., thermoelectric) or carbon and non-carbon outputs from production processes (i.e., methane from cattle). Firms optimally decide on the demand for fossil and green energy, as the level of effort dedicated to abating emissions coming from production processes. Two alternative policies for emissions, which include emissions taxation (fixed cost) and emission permits trade (quantity caps), are introduced into an open-economy DSGE model for the Brazilian economy. Departing from the estimated parameters of the original version of the model, ratios in the new block of equations for the energy and emissions are calibrated using sectoral data, and some elasticities are set to reproduce the sensibility to some shocks implicit in the NGFS11Network for Greening the Financial System. scenarios (Net Zero 2050). Simulations indicate neither of the emissions policies can induce transition in the energy matrix without a green investment policy. The approach adopted here is a first step in building a macroeconomic model capable of challenging scenarios from more specialized models dedicated to energy and emissions by better assessing possible effects and feedback related to the iterations with macroeconomic dynamics. Despite the difficulties concerning the limited availability of data in higher frequency, results indicate those modeling approaches are sufficiently flexible to incorporate the main aspects of energy and emission, serving as valuable tools for policy analysis.

Startup characteristics of a water loop heat pipe with dual heat sources for battery thermal management system in electric vehicle

Abstract The usage of electric vehicles has significantly reduced emissions of greenhouse gases and other pollutants. However, the high heat release generated by the electric vehicle batteries poses a challenge. To solve this problem, scientists have created a passive cooling thermal management system specifically for electric vehicle based on heat pipes, particularly loop heat pipes. A battery pack often consists of several battery modules, which results in multiple heat sources being dispersed according to their power capacity. Startup behavior of loop heat pipe has been investigated extensively in the literature. However, most of the studies use only one heat source. This paper aims to fill the research gap, particularly when the system is implemented in dual heat sources managed by only one evaporator. To achieve the research objectives, a custom loop heat pipe was constructed. This cooling system’s design is briefly described. The evaporator is made of copper, deionized water was selected as the working fluid because of its high merit number, which indicates strong performance as a heat pipe working fluid and the stainless-steel wire mesh serves as the porous wick. Battery simulator was built using aluminum material and a cartridge heater to mimic the heat produced by the battery. Two case studies were done. First, only one battery simulator was used. Second, two battery simulators were placed on both sides of the evaporator. A type-K thermocouple attached to the NI DAQ 9214 module was used to measure the temperature while the electric heat load varied between 10 W and 50 W. The study investigated the interaction between the heat load distribution and the startup behavior of the loop heat pipe. Startup behavior is crucial for the performance of the loop heat pipe. Based on the experimental results, the loop heat pipe demonstrates outstanding startup performance. It can effectively initiate operation even at a minimal heat load as low as 30 W for the first and second case study. The findings of the study indicate that the dual heat source arrangement effectively mitigates overshoot temperatures and enhances heat transfer performance by increasing the contact area.

Study on the synergistic control of nitrogenous emissions and greenhouse gas of ammonia/diesel dual direct injection two-stroke engine

This study developed a numerical model for an ammonia/diesel dual direct-injection two-stroke engine and validated it based on engine bench test results. The engine combustion and emission characteristics were discussed under the cases of different injection parameters, intake temperatures, and exhaust gas re-circulation (EGR) rates. The findings indicate that altering the injection angle of ammonia and diesel sprays impacts the in-cylinder swirl and the ignition timing of the ammonia spray, consequently affecting the heat release phase of ammonia combustion. A suitable arrangement spray plumes can effectively reduce the emissions of unburned ammonia and greenhouse gas (GHG), while increase the emissions of NOx. On the other hand, higher intake temperatures can increase the average in-cylinder temperature, reducing unburned ammonia, N2O and GHG emissions. However, it also results in greater NO emissions, which can affect fuel economy negatively. Furthermore, the use of EGR technology can reduce the combustion temperature, thereby lowering the emission of nitrogen-based pollutants, but it also reduces ammonia combustion efficiency. By simultaneously applying the three aforementioned technologies within a certain range of conditions, it is possible to effectively synergize and control nitrogenous emissions and GHG while maintaining high thermal efficiency of ammonia/diesel dual direct injection engines.

Mechanisms underlying variations in pore structures and permeability in response to thermal treatment and their implications for underground coal utilization

Coal remains a predominant energy source in today's society. However, the coal mining process is associated with severe environmental hazards, and combustion for power generation leads to pollution and carbon dioxide emissions. As a result, many countries have imposed restrictions on underground coal mining. Underground coal gasification, direct combustion for heat recovery and thermal treatment provides serval promising way for cleanly and safely utilizing coal resources. However, the successful operation of these technologies needs to comprehensively understand the physical and chemical properties of coal responding to high temperature. In particular, the pore structures and permeability of coal which are closely related to the transport of gas and liquid in coal seams. Therefore, serval advanced instruments were employed to investigate the variation of the functional groups, pore structures, permeability from room temperature to 500 °C. Their connection was discussed in detail to reveal the mechanism of thermal treatment on the pore structures and permeability of coal. The variations of all physical properties with temperature demonstrated a trend of gradual change followed by a sudden change. This indicated that coal samples possess relatively good stability up to 300 °C. Experimental results revealed significant alterations in the pore structure and permeability of the coal at 400 °C and 500 °C. Correspondingly, the mass of coal samples and the CC functional groups, which constitute the main molecular structure of coal, underwent significant changes at these temperatures. This suggested that the pyrolysis of coal beyond 400 °C led to an increase in both pore volume and permeability. Moreover, observations through scanning electron microscopy indicated that the increase in pore volume at 400 °C and 500 °C also resulted from the thermal stress induced cracks between minerals and organic matters. These mechanisms significantly enhance the pore volume and permeability of coal seams, facilitating the transport of coalbed gases and liquids during the production process of underground coal utilization.

Life cycle assessment and comparison of energy supply system technical innovation: A case study

As the key sector of energy consumption in China, the industrial sector contributes the most to environmental pollution and CO2 emissions. With the goals of reaching the peak of CO2 emissions by 2030 and achieving carbon neutrality by 2060, optimizing the energy supply system of industrial enterprises is significant to achieve low-carbon development. In this study, the case of system upgrading concerning waste heat utilization in a manufacturing unit is applied. The total environmental impact of the energy supply system before and after transformation is quantified and compared based on life cycle assessment method, with “cradle to gate” as the system boundary and one year of system operation as the functional unit. It can be found that the environmental impact of the energy supply system is reduced from 4.54 to 4.14 through technical innovation. The key processes contributing to the environmental impact of the system are the refrigeration system, soft water system and boiler system. Electricity consumption of refrigeration system, NaCl of the soft water system and natural gas of the boiler system are identified as key substances. Sensitivity analysis reveals that the environmental benefits of reducing electricity consumption will be more effective than that of NaCl and natural gas. With the transformation of waste heat utilization and the increase of photovoltaic power generation, the environmental impact of the system is reduced obviously, which is significant for the low-carbon transformation of the manufacturing industry.

The Future of Environmental Engineering Technology: A Disruptive Innovation Perspective

Scientific and technological revolutions and industrial transformations have accelerated the rate of innovation in environmental engineering technologies. However, few researchers have evaluated the current status and future trends of technologies. This paper summarizes the current research status in eight major subfields of environmental engineering—water treatment, air pollution control, soil/solid waste management, environmental biotechnology, environmental engineering equipment, emerging contaminants, synergistic reduction in pollution and carbon emissions, environmental risk, and intelligent management—based on bibliometric analysis and future trends in greenization, low carbonization, and intelligentization. Disruptive technologies are further identified based on discontinuous transformation, and ten such technologies are proposed, covering general and specific fields, technical links, and value sources. Additionally, the background and key innovations in disruptive technologies are elucidated in detail. This study not only provides a scientific basis for strategic decision-making, planning, and implementation in the environmental engineering field but also offers methodological guidance for the research and determination of breakthrough technologies in other areas.

Sizing requirements of the photovoltaic charging station for small electrical vehicles

Electric vehicles (EVs) are being introduced in Rwanda and becoming attractive for different reasons. For instance, these types of vehicles can help decrease air pollution and noise emissions. In addition, it presents an alternative to combustion engines, given the increased price of fuel resources in Rwanda and around the world. This paper presents a tool tailored to optimize the design of an electrical charging station serving small-sized electric vehicles, utilizing the algorithm to assist in sizing stand-alone mopped charging stations. The developed tool is based on the toolbox EventSim from MathWorks, which permits the combination of the simulation of discrete events (such as the arrival of customers at the station) with continuous states (such as the simulation of the charging process). The required PV power was estimated by utilizing solar resources, for the location, from renewables. Ninja. The number of customers arriving at the existing oil station is normalized to estimate the energy requirements of the mopped fleet. A Poisson distribution was proposed to model the battery discharge upon arrival, and different related parameters were evaluated through a sensitivity analysis to identify their effects on the performance of photovoltaic charging station. For the testing values, the station parameters were changed by ±25% to determine the impact of key design parameters on station performance, as well as other satisfaction measures such as average waiting time and average queue length. With a 25% increase in photovoltaic panels, the blackout period decreases by 2.12%, while a 25% decrease in photovoltaic panels causes an increase of 2.18% in the blackout period. Utilizing the energy management system (EMS), the waiting time was reduced by 8%.

Optimization of engine performance, emission and combustion parameters by using mixed nonedible oil biodiesel with nano-additives using hybrid techniques

The current study is focused on three nonedible oils resource such as Ceiba pentandra, Mahua longifolia, and Azadirachta indica mixed together in a specific proportion for biodiesel production. The produced biodiesel serves as an alternative fuel source for operating a variable compression ratio diesel engine, addressing escalating environmental pollution and stringent emission standards. A nano-additive comprising CaO-TiO2 is incorporated into biodiesel blends to enhance engine performance and mitigate emissions. The matrix undergoes experimentation and validation using Box-Behnken Design, Deep Belief Network, and a hybrid DBN-based Arithmetic Optimization Algorithm to optimize engine parameters for achieving higher brake thermal efficiency, lower emission rates, and reduced brake-specific fuel consumption. All the experiments are conducted by varying the engine load, speed, quantity of nano-additives and biodiesel blend. The final empirical model is more significant for DBN with a regression coefficient greater than 0.99. The converged optimized input parametric ranges are load 60%, biodiesel 25%, nano-additive 20 wt.% and engine speed 1400 rpm. When comparing diesel fuel with CaO-TiO2 biodiesel, the proposed method resulted in significant improvements, including a 41% reduction in brake-specific fuel consumption, a 32% decrease in CO emissions, a 25% decrease in NOX emissions, and a 16.9% increase in brake thermal efficiency.

Bioactive Compounds from Kinnow Processing Waste and their Associated Benefits: A Review.

We have explored the expansive possibilities of kinnow peel, a frequently ignored by-product of the fruit processing industry, in this thorough analysis. The production of kinnow generates a significant amount of waste, including peel, seeds, and pulp. The disposal of this waste is a major environmental issue, as it can lead to pollution and greenhouse gas emissions. Due to the presence of bioactive substances that may be used in a variety of sectors, kinnow processing waste has the potential to provide a number of advantages. In the culinary, pharmaceutical, and cosmetic industries, the peel, seeds, and pulp from kinnow can be used as natural sources of antioxidants, aromatics, pectin, and dietary fibre. Utilizing kinnow waste promotes eco-innovation, increases sustainability, and aids in waste reduction. The development of a circular economy can be sped up with more study and commercialization of kinnow waste products. This analysis emphasises how important it is to understand and utilise the unrealized potential of agricultural byproducts, like kinnow peel.

Modelling of JP-8 distributed combustion using a HyChem mechanism under gas turbine conditions

The critical advantages of liquid fuels in aviation over alternative energy carriers imply their dominance in the upcoming decades. The Mixture Temperature Controlled (MTC) combustion concept allows spatially homogeneous, efficient burning (distributed combustion) with low pollutant emission. MTC combustion of jet fuel JP-8 was investigated in an atmospheric burner, and the measured pollutant concentrations in the flue gas were reproduced using the Hybrid Chemistry (HyChem) approach employing Perfectly Stirred Reactor simulations. Using this robust approach comes with losing spatiotemporal characteristics if the mixture homogeneity assumption is globally valid. The effect of residence time and pressure under typical gas turbine operating conditions was investigated. Stable combustion was present above 3 ms residence time at all pressures, while the lower limit was 0.3 ms. The residence time interval of stable operation could be extended by applying flue gas recirculation. NO emission can be reduced by increasing the operating pressure, while the N2O production is dominant only up to 20 bar and in the 10–100 ms residence time range. CO emission vanishes above 10 ms residence time. Ultra-low emission operation requires >20 bar pressure and 10 ms residence time with distributed combustion, requiring larger combustion chambers for future jet engines.

The Impact of Energy (Electricity) Losses on Load Capacity Factor: A Dynamic ARDL-Based Evidence from Pakistan

The energy-environment interplay has raised significant concerns among policymakers and experts, with the global shift towards renewable energy being hailed as a key solution to reduce pollution emissions. However, in addition to energy production, the efficient transmission and distribution of electricity is also important which also poses considerable challenges to environmental sustainability. This study aims to investigate the effect of electricity losses on environmental sustainability measured by load capacity factor (LCF). This study uses the DARDL (DARDL) method and Kernel-based Regularized Least Squares (KRLS) to analyze the influence of electricity losses, foreign direct investment (FDI), economic growth, and industrial output on LCF in Pakistan from 1981 to 2022. The electricity losses significantly undermine environmental sustainability by reducing LCF. However, FDI positively influences LCF, but economic growth and industrial output exert a detrimental effect. Additionally, the study observes that both positive and negative counterfactual 10% shocks in electricity losses result in negative and positive impacts on LCF. Whereas, 10% positive counterfactual shocks in FDI positively affect LCF. KRLS analysis confirms the robustness of the DARDL estimates. The study underscores that efficient energy transmission and distribution is pivotal in safeguarding environmental sustainability.

Co-combustion of municipal sewage sludge and food wastes-derived anerobic digestates: Combustion characteristics, HCl/NO/SO2 emission and ash behaviors

Co-combustion of sewage sludge (SS) and food wastes-derived anerobic digestate (AD) is a promising way of waste-to-energy. Therefore, it is crucial to examine their combustion performance, ash behaviors, and gaseous pollutants emissions during the combustion of AD-SS blends using a thermogravimetric analyzer and a tube furnace combustion system. Results show that obvious interactions between AD and SS are observed in their co-combustion process. In terms of comprehensive combustion index, co-combustion can improve their combustion performance with the decrement of burnout temperature and enhanced combustion reactivity. Higher blending ratio of AD favors the increment of their ash fusion temperature, i.e., from 1109 to 1403oC for deformation temperature due to the formation of high melting point minerals (i.e., Ca9Fe(PO4)7, 2CaO·Al2O3·SiO2). Significant in-situ reduction of NO and HCl as well as self-desulfurization is observed during the combustion of AD-SS blends. Compared to the theoretical values, the emission amount of HCl, NO, and SO2 is reduced by 0.13, 1.39, and 0.35mg·g-1, respectively at 850oC and blending ratio of AD to SS = 0.75:0.25. These phenomena are associated with the reducing environment and reducing substances by their high volatiles as well as the abundant minerals such as CaCO3 and Fe2O3 in AD and SS. However, high combustion temperature is unfavorable for chlorine fixation. This work provides a better understanding of their thermal behaviors, ash characteristics, and gaseous pollutants emission characteristics to realize their stable and clean incineration.

Sulfured FeMo carbides and nitrides catalysts upgrade extra heavy crude oil quality

In the context of the energy transition scenario, effective sulfur management is crucial. Enhancing the quality of extra heavy crude oil (EHCO) through catalytic processes, specifically hydrotreatment, is essential for reducing pollutant emissions like SOx into the atmosphere. Traditional hydrotreatment, utilizing MoS2-based catalysts typically on Al2O3 support, faces challenges with EHCO due to its elevated S and N content, which hampers catalyst efficiency. Metal carbides and nitrides exhibit promising electronic structures that confer resistance to deactivation in the presence of heteroatoms. This study compares the catalytic performances of Fe-promoted Mo sulfides, carbides, and nitrides (FeMoS(C,N)) in the thiophene hydrodesulfurization (HDS) reaction, serving as a model molecule for sulfur removal. Subsequently, we investigate the upgrading of a Venezuelan EHCO in terms of pollutant reduction, API gravity, and feedstock aromaticity. Catalysts were prepared from oxide precursors, varying the (Fe/(Fe+Mo)) atomic ratios (x = 0.00, 0.10, 0.33, 0.50, and 1.00), employing a temperature-programmed reaction protocol. Catalytic upgrading of EHCO was conducted in a stirred batch reactor, and the results were compared with a commercial CoMo-based catalyst. FeMoC(N) outperformed the commercial catalyst in sulfur removal. The elemental composition and nitrogen content of the feed remained constant; however, the sulfur content of asphaltenes decreased. Furthermore, the API gravity of crude oil increased when employing FeMoS and FeMoN catalysts, except with FeMoC, possibly linked to dealkylation reactions and the enrichment of lighter fractions with alkanes. FeMoN increased asphaltene aromaticity, while FeMoC decreased it. These results highlight the promise of FeMoC(N) as catalysts for HDS and upgrading heavy feedstocks.

The effect of government-firm relationship on pollution reduction: The role of official performance appraisal

This paper investigates the unexpected positive effect of the government-firm relationship on environmental governance in the context of the reform of official performance appraisal (OPA) in China. In 2013, the central government launched an OPA reform that aimed to reduce the dependence on GDP growth and increase the focus on environmental protection in the appraisal process. According to the empirical results, in cities with mayors who have promotion incentives, firms that received favor from local governments can significantly reduce air pollutant emissions after the OPA reform. These findings remain robust even after conducting various tests, such as parallel trend test, omitted variables, and alternative explanations. This paper demonstrates that a reciprocal relationship between governments and firms can benefit society with the appropriate incentives.

Study of ignition and combustion of aluminum/ethanol nanofluid based on reactive molecular dynamics simulation

Aluminum/ethanol nanofluid fuel offers high energy density, high combustion efficiency, and low pollutant emissions, making it highly promising for aerospace applications. In recent years, the fundamental combustion characteristics for aluminum/ethanol nanofluid fuel have been extensively studied. However, current experimental techniques are still difficult to reveal the micro-mechanisms ignition and combustion of aluminum/ethanol nanofluid fuel. Hence, the ignition and combustion mechanisms of aluminum/ethanol nanofluid fuel were investigated from a microscopic point of view through reactive molecular dynamics simulation. The simulation results show that the mechanisms of enhanced ethanol combustion by aluminum nanoparticles mainly consists of micro-explosion at high temperature and small particle size, chain reaction at low temperature and large particle size, melt-dispersion in the mild oxidation state and diffusive oxidation in the moderate and heavy oxidation states. In addition, the initial stage of the combustion of aluminum nanoparticles with core-shell structure in ethanol is mainly a non-homogeneous surface reaction. This work reveals the combustion characteristics and mechanisms of aluminum/ethanol nanofluid fuel from an atomic perspective, which is expected to provide insights for the exploration and application of ethanol-based nanofluid fuel in the future.

Synthesis of Ceiba pentandra biodiesel using ultrasound and infrared radiation: Comparison and fuel characterisation.

Abstract The continuous expending of the economy and population in modern society has caused an increase in energy usage. Currently, fossil fuels and renewable energy are used to generate energy, contributing to greenhouse gas emissions. A significant effort has been made globally to address the issue of rising emissions by boosting the usage of renewable energy. In comparison to fossil fuels, biodiesel has many benefits, including the ability to be produced from a wide range of feedstocks, the ability to be renewable, and the reduction of atmospheric pollution emissions. Besides, advanced technologies can help the biodiesel sector meet the energy demand while producing high-quality biodiesel. The Ceiba pentandra was used for biodiesel production using ultrasound-infrared applications in the present research work. The study aims to produce biodiesel for a better conversion rate and improve fuel properties. Comparisons were conducted using a combination of infrared ultrasound versus ultrasound irradiation. The results show that ultrasound produced the highest yield of 98.76% when the conditions were as follows: methanol/oil ratio: 60%, KOH: 1%, reaction time: 50 minutes. Yet, the addition of infrared on ultrasound has also produced a high conversion yield in a shorter time than ultrasound. A 98.42% biodiesel yield option when using infrared-ultrasound irradiation with conditions as follows: methanol/oil ratio: 60%, KOH: 1%, reaction time: 30 minutes. As both applications were examined, the ultrasound-infrared application was preferable in saving time and energy constraints for biodiesel production. The fuel properties were found to be equivalent to ASTM D6751 and EN 14214 biodiesel standards.

Hourly effect of atmospheric reactive nitrogen species on the onset of acute ischemic stroke: Insight from the Shanghai Stroke Service System Database

Acute ischemic stroke (AIS) is one of the most predominant causes of mortality and disability in China. Significant uncertainties in stroke diagnosis and time of onset have resulted in inconsistent evidence on the association between ambient air pollution and the risk of AIS. The present study aimed to evaluate the impact of air pollution on AIS onset based on high time-resolution air pollution data and a stroke-specific registry across the past five years. Hourly concentrations of PM2.5, PM10, O3, SO2, CO, NO2 and nitrous acid (HONO) were monitored from 2017 to 2021, with which a distributed lag non-linear model and conditional logistic regression models coupled with a time-stratified case-crossover design were applied to 106,623 AIS cases recorded in the Shanghai Stroke Service (4S) database during the study period. Results from the conditional logistic regression models indicate that acute exposure to PM2.5, PM10, SO2, NO2 and HONO was found to be associated with AIS onset, respectively. The corresponding cumulative excessive risks of AIS onset were 0.8 %, 1 %, 2.4 %, 2.1 % and 1.8 % for each interquartile range increase in the respective concentration. The longest lag-effect (up to 13 h) was observed for reactive nitrogen species (RNS), such as NO2 and HONO, which remained robust in two-pollutant models. Similar important role of RNS in AIS onset were confirmed by the distributed lag non-linear model. By demonstrating the transient effect of ambient air pollution on AIS, especially the relationships between RNS and AIS for the first time, our study provides stringent evidence for future mitigation strategies for pollution emission and public health.