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Governmental subsidy policy and channel information structure have substantial effects on supply chain emission reduction, operations and marketing decisions. In this paper, we use game theory to study the interplay of government subsidizing arrangement and information asymmetry on manufacturers' emission reduction and retailers' low-carbon promotion. Suppose realistically that the investment coefficients for manufacturers' emission reduction levels and retailer' low-carbon promotion levels are their respective private information. Among diverse governmental subsidy schemes, we find dual subsidizing are the best choice for the defined level of total subsidy under information asymmetry, while it is not always the best choice if the total subsidy level is uncertain. Under information asymmetry, the results show that manufacturer have no incentive to lie under any subsidy policy. However, the retailer has incentive to misrepresent individual information and its misreporting behaviour is related to the coefficient and allocation ratio of governmental subsidies. On this basis, we illustrate that a screening model can be deployed to reduce the negative effects of information asymmetry on supply chain operations. We therefore propose the method of improving the performance of low-carbon supply chains under various situations of information asymmetry and governmental subsidizing schemes to achieve system-wide Pareto improvement. [ABSTRACT FROM AUTHOR]

Consumers' growing awareness of environmental protection and carbon regulations enacted by the government based on strengthened environmental pressure are forcing manufacturers to curb carbon emissions. This paper considers a manufacturer investing in green technology to reduce carbon emissions under the cap-and-trade regulation, selling products to consumers through a direct channel and an online retail platform. The platform could choose to operate either in an agency mode or a reselling mode. A three-stage game is constructed to examine the interactions between the manufacturer's investment and the platform's operation mode under the cap-and-trade regulation, as well as the influences of the regulation on the interactions, and the supply chain coordination. The findings suggest that green technology investment in either operation mode leads to Pareto improvement in profits of both the platform and the manufacturer, and the investment induces the platform to prefer the reselling mode. Besides, the cap-and-trade regulation encourages the platform to opt for the agency mode, while the investment could mitigate the influence of the regulation on the platform's mode choice, with greater investment efficiency resulting in better mitigation. Furthermore, the investment could induce supply chain coordination under two modes through two different contracts. [ABSTRACT FROM AUTHOR]

Carbon tax represents governments' approach to steering the economy towards a greener future. Our research question focuses on the impact of carbon tax policy on a firm's production decision and revenue and on total social welfare. In particular, we assume that a firm's decision is subject to its behavioural considerations or, in other words, its risk attitude. We model a government plan to charge a carbon tax, and a risk-averse (or risk-neutral) firm needs to plan its production and estimate its profit if the carbon tax policy is implemented. We show that it is possible for a risk-averse firm's optimal profit, in some cases, to be higher than that of a risk-neutral firm when facing a carbon tax. This implies that the risk-averse attitude is not necessarily harmful to the firm's profit. For operations management scholars, our model highlights the importance of integrating firms' behavioural responses into the carbon tax price. Our model suggests that for governments to implement carbon tax policy effectively, they should make carbon prices vary under certain conditions and not worry about price variation antagonising firms at large. [ABSTRACT FROM AUTHOR]

We consider a low-carbon tourism supply chain (LTSC) network composed of two low-carbon scenic spots (LSSs) and two travel agencies (TAs). The LSSs as leaders and the TAs as followers play Stackelberg games in the vertical direction. Meanwhile, the competing LSSs play Nash game to determine emission reduction efforts and ticket prices, and the competing TAs play Nash game to conduct retail prices. We establish four kinds of differential game models with different LTSC network structures, derive the equilibrium decision-makings of the LSSs and TAs, and explore the influences of competition or cooperation at vertical and horizontal level of the LTSC network members on the equilibrium solutions of the LSSs and TAs, low-carbon level of tourism products and performance of the LTSC network. Then, we find that the low-carbon preference of tourists improves the low-carbon level of tourism products, while the competition intensity between the LSSs leads to the decrease of the low-carbon level of tourism products. In addition, the results indicate that horizontal or vertical cooperations among the LTSC network members are not always conducive to the performance of the whole LTSC network. Only when the sensitivity of tourist demand to retail price meets certain conditions, these cooperations can develop tourism products with higher low-carbon level and bring higher revenues. [ABSTRACT FROM AUTHOR]

The rising costs of petroleum-based fuels for internal combustion engines and their detrimental environmental impacts have spurred the search for alternative fuels. This study explores minor modifications to a compression ignition engine, enabling it to operate in dual fuel mode using biofuels as a viable alternative to neat diesel. A novel biofuel was developed using cedar wood oil, and its performance was experimentally investigated in a single-cylinder diesel engine operating at a constant speed. Acetylene was continuously introduced to the engine at a flow rate of 6 L per minute, chosen for its optimal performance, yielding a brake thermal efficiency of over 30.7%. The engine was operated under constant conditions, including a compression ratio of 18, an ignition timing of 23°CA before top dead centre, and an injection pressure of 220 bar. Comparative evaluations were performed by analyzing the combustion characteristics and emission levels of diesel and cedar wood oil-based fuels with and without nanoadditive for diesel, B50 and B100 with a constant acetylene gas supply at 6 Lit/min. The primary objective was to reduce toxic emissions, including smoke, carbon monoxide, hydrocarbons, and nitrogen oxides, released during fuel combustion with the help nanoadditives in fuel. The effects of cerium nanoparticles as an additive were considered in this study due its thermal stability and activation energy which reduce CO and HC emission significantly.The smoke, CO and HC were decreased for B100 + 6L A + 50 ppm blend by 20.21%, 65.52% and 51.42% for 100% load. It is found that cedar wood oil oil with nanoparticle additives could effectively reduce smoke and hydrocarbon emissions while maintaining comparable efficiency to neat diesel and pure biodiesel modes. [ABSTRACT FROM AUTHOR]

In recent years, the concentrations of ozone and the pollution days with ozone as the primary pollutant have been increasing year by year. The sources of regional ozone mainly depend on local photochemical formation and transboundary transport. The latter is influenced by different weather circulations. How to effectively reduce the inter-regional emission to control ozone pollution under different atmospheric circulation is rarely reported. In this study, we classify the atmospheric circulation of ozone pollution days from 2014 to 2019 over Central China based on the Lamb–Jenkinson method and the global analysis data of the fifth-generation European Centre for Medium-Range Weather Forecasts (ECMWF) Reanalysis (ERA5) operation. The effectiveness of emission control to alleviate ozone pollution under different atmospheric circulation is simulated by the WRF-Chem model. Among the 26 types of circulation patterns, 9 types of pollution days account for 79.5% of the total pollution days and further classified into 5 types. The local types (A and C type) are characterized by low surface wind speed and stable weather conditions over Central China due to a high-pressure system or a southwest vortex low-pressure system, blocking the diffusion of pollutants. Sensitivity simulations of A-type show that this heavy pollution process is mainly contributed by local emission sources. Removing the anthropogenic emission of pollutants over Central China would reduce the ozone concentration by 39.1%. The other three circulation patterns show pollution of transport characteristics affected by easterly, northerly, or southerly winds (N-EC, EC, S-EC-type). Under the EC-type, removing anthropogenic pollutants of East China would reduce the ozone concentration by 22.7% in Central China. [ABSTRACT FROM AUTHOR]

This study addresses the ongoing demand for increased efficiency and reduced emissions in turbomachinery combustion systems. A custom-built high-pressure combustor was designed and manufactured at the Low Carbon Combustion Centre (LCCC) of the University of Sheffield to investigate the impact of different aromatic hydrocarbons on emission rates. The research involved the comprehensive testing of Jet−A1 fuel and six aromatic species blends under high-pressure conditions of 10 bar. Based on the numerical CFD simulations by ANSYS 19.2, tangential dual air injection and a strategically placed V-shaped baffle plate were utilised to enhance fuel-air mixing and combustion stability. Experimental results demonstrated a negative correlation between combustion temperature and particulate matter (PM) emissions, with higher temperatures yielding lower PM emissions. Unburned hydrocarbons (UHCs), nitrogen oxides ( N O x ), carbon monoxide ( C O ), and carbon dioxide ( C O 2 ) emissions were also analysed. Ethylbenzene produced the highest UHC and C O emissions, while Indane exhibited the lowest levels of these pollutants, suggesting more complete combustion. O−xylene generated the highest N O x emissions, correlating with its higher combustion temperatures. This research enhances our understanding of gas turbine combustor design and the combustion behaviour of aromatic species, providing valuable insights for developing low-emission, high-efficiency gas turbine combustion technologies. [ABSTRACT FROM AUTHOR]

This study investigates the enhancement of combustion efficiency in a dual-fuel diesel engine powered with oxyhydrogen as the primary fuel and a Graphene oxide nanoparticle-dispersed biodiesel/diesel blend as the pilot fuel. A Box-Behnken design (BBD) is employed to develop an L 17 orthogonal array for three factors and three levels of input parameters: engine load, HHO flow rate, and EGR ratio. An RSM-based 3D surface plot is utilized to analyze the interaction between input parameters and responses. Multi-objective optimization through RSM-based desirability and genetic algorithms (MOGA) is conducted to obtain the optimal engine operating parameters. The MOGA approach demonstrates superior performance compared to the RSM-based desirability approach. The optimal engine operating parameters identified by the MOGA approach are an engine load of 9.89 kg (approximately 3.43 kW), an HHO flow rate of 5.78 L/min, and an exhaust gas recirculation (EGR) ratio of 10.18%. At this optimized operating condition, the performance and combustion output are 31.85% BTE, 0.3268 kg/kWh of BSFC, and 60.16 bar of peak cylinder pressure (PCP). In terms of emissions, carbon monoxide (CO) is 0.04152 vol %, hydrocarbon (HC) is 25.45 ppm, and nitrogen oxide (NO x) is 746.12 ppm. Experimental validation confirms that all results are within an acceptable limit with a maximum error of 6%. Oxyhydrogen significantly enhances fuel efficiency and consumption while simultaneously reducing carbon-based emission levels, except for nitrogen oxide emissions. The adverse effects of an increase in NO x are mitigated by the addition of EGR. [Display omitted] • Biodiesel synthesis using ultrasonic-assisted technology. • Study of dual-fuelled diesel engine behavior with nanoparticles, HHO and EGR. • Application of RSM-based predictive models for performance and emission analysis. • Multi-objective optimization through RSM and GA for engine response optimization. • The optimal engine operating conditions are: load 9.89 kg, HHO flow rate 5.78 L/min, and EGR 10%. [ABSTRACT FROM AUTHOR]

Collision welding is a promising approach for joining conventional materials in identical or dissimilar combinations without heat-related strength loss, thereby opening up new lightweight potential. Widespread application of this technology is still limited by an insufficient state of knowledge with respect to the underlying joining mechanisms. This paper applies collision welding to a material combination of DC04 steel and EN AW 6016 aluminium alloy. Firstly, the welding process window for the combination is determined by varying the collision speed and the collision angle, the two main influencing variables in collision welding, using a special model test rig. The process window area with the highest shear tensile strength of the welded joint is then determined using shear tensile tests and SEM images of the weld zone. The SEM investigations reveal four distinct metallographic structures in the weld zones, the area fractions of which are determined and correlated with collision angle and shear tensile strength. [ABSTRACT FROM AUTHOR]

Existing studies have limited evidence about the complex nonlinear impact mechanism of road network topology and built environment on bike-sharing systems' greenhouse gas (GHG) emission reduction benefits. To fill this gap, we examine the nonlinear effects of road network topological attributes and built environment elements on the potential GHG emission reduction of dockless bike-sharing (DBS) trips in Shenzhen, China. Various methods are employed in the research framework of this study, including a GHG emission reduction estimation model, spatial design network analysis (sDNA), gradient boosting decision tree (GBDT), and partial dependence plots (PDPs). Results show that road network topological variables have the leading role in determining the potential GHG emission reduction of DBS trips, followed by land use variables and transit-related variables. Moreover, the nonlinear impacts of road network topological variables and built environment variables show certain threshold intervals for the potential GHG emission reduction of DBS trips. Furthermore, the impact of built environment on the potential GHG emission reduction of DBS trips is moderated by road network topological indicators (closeness and betweenness). Compared with betweenness, closeness has a greater moderating effect on built environment variables. These findings provide empirical evidence for guiding bike-sharing system planning, bike-sharing rebalancing strategy optimization, and low-carbon travel policy formulation. [ABSTRACT FROM AUTHOR]

The current work focuses on the usage of a sustainable fuel derived from Senna auriculata seed through pyrolysis for IC engine applications. Batch-type reactor was employed to produce the bio-oil through pyrolysis, and it was found that the optimum temperature of 550 °C is suitable for a maximum yield of 46%. Physical characterization of the produced SA oil is examined as per ASTM standards, and chemical characterization is studied using FTIR, 1HNMR, and GC–MS analysis to study and compare with conventional diesel. The performance of the engine, along with combustion and emission analysis, was carried out with blends of SA and diesel. The results investigated were compared with those of conventional diesel. The efficiency for the SA10 blend was estimated to be 34.5%, which is 1.27% higher than regular diesel fuel under full-load conditions. Emission analysis portrayed the CO and UHC emissions as low, whereas the increase in NOX emissions was due to the high temperature inside the cylinder and the presence of oxygen. The SA10 blends exhibited comparable performance and emission results with commercial diesel fuel under normal working conditions. This research provides an integrated approach to selecting the precise biomass and establishing sustainable bioenergy recovery as the future energy resolution. [ABSTRACT FROM AUTHOR]

One of the most important issues in the maritime industry is controlling and reducing the amount of emissions caused by marine vessels. In this respect, the International Maritime Organization sets some air pollution-related regulations and encourages maritime companies to utilise current and innovative emission abatement methods on their ships. The application of these approaches to ships not only provides environmental benefits but also creates additional financial costs for the company. In this study, operational data of a container ship has been acquired and examined. Methods such as ammonia, LNG, scrubber, low sulphur fuel use, and selective catalytic reduction have been considered to determine the most appropriate emission reduction approach. Nine different scenarios have been created with the use of stated methods and each scenario is analysed both environmentally and economically and compared to each other. Finally, the most suitable scenario has been determined by calculating the payback period of each investment. Since there is a relatively longer period of redemption, using a dual-fuel engine could be more suitable for long-lasting and newly built ships. For the currently cruising ships, the use of scrubber systems with selective catalytic reduction is an effective solution to reduce the number of emissions. [ABSTRACT FROM AUTHOR]

Textile production has received considerable attention owing to its significance in production value, the complexity of its manufacturing processes and the extensive reach of its supply chains. However, textile industry consumes substantial energy and materials and emits greenhouse gases that severely harm the environment. In addressing this challenge, the concept of sustainable production offers crucial guidance for the sustainable development of the textile industry. Low-carbon manufacturing technologies provide robust technical support for the textile industry to transition to a low-carbon model by optimizing production processes, enhancing energy efficiency and minimizing material waste. Consequently, low-carbon manufacturing technologies have gradually been implemented in sustainable textile production scenarios. However, while research on low-carbon manufacturing technologies for textile production has advanced, these studies predominantly concentrate on theoretical methods, with relatively limited exploration of practical applications. To address this gap, a thorough overview of carbon emission management methods and tools in textile production, as well as the characteristics and influencing factors of carbon emissions in key textile manufacturing processes is presented to identify common issues. Additionally, two new concepts, carbon knowledge graph and carbon traceability, are introduced, offering strategic recommendations and application directions for the low-carbon development of sustainable textile production. Beginning with seven key aspects of sustainable textile production, the characteristics of carbon emissions and their influencing factors in key textile manufacturing process are systematically summarized. The aim is to provide guidance and optimization strategies for future emission reduction efforts by exploring the carbon emission situations and influencing factors at each stage. Furthermore, the potential and challenges of carbon knowledge graph technology are summarized in achieving carbon traceability, and several research ideas and suggestions are proposed. [ABSTRACT FROM AUTHOR]

The environmental and economic performance of a post‐combustion solvent‐based carbon capture system (CCS) combined with a selective catalytic reduction (SCR) system is investigated on a 48,600 kW engine container ship to meet the International Maritime Organization's emission reduction strategies through 2050. The proposed system uses aqueous ammonia to mitigate the produced CO2 and NOX emissions onboard a ship. Moreover, the combined system is investigated through a voyage‐based case study using an engine room simulator, assuming that CCS and SCR are implemented on the reference ship. During the case study, the referenced container ship sailed from Rotterdam to New York, and the estimations were made by using Netpas Distance 4.0 software program. Results indicate that a total of 3,606.04 ton‐CO2 and 92.40 ton‐NOX are produced, while 3,345.43 ton‐CO2 and 40.67 ton‐NOX are captured during the voyage. Furthermore, an economic analysis is carried out after the case study. Findings of the economic analysis are: CAPEX of CCS is $32.07 MM and SCR is $2.19 MM, while OPEX of CCS and SCR are $188,873 and $103,681, respectively. In addition, it was calculated that implementing CCS could avoid the CO2 tax cost of $19,472, while the economic value of the CO2 captured was $113,590. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This study investigates the dynamics of carbon emissions in Azerbaijan from 1990 to 2020, analyzing trends, influencing factors, and policy implications. Azerbaijan initially exceeded global averages in per capita carbon emissions but has since achieved significant reductions, driven by ongoing policy initiatives and other factors. Sector-specific analyses underscore the energy sector's central role in emissions, highlighting the importance of technological innovation and targeted strategies to achieve sustainable development goals. The industrial sector is the primary energy consumer, relying heavily on crude oil and natural gas. Conversely, advancements in fuel quality and vehicle replacement have resulted in the transport sector, despite its increased energy consumption and pollutant outputs, having relatively lower impacts compared to stationary sources. The research reveals a significant positive relationship between energy consumption in the transport sector and atmospheric pollution. Specifically, a one-unit increase in energy consumption leads to an approximate 0.1548 unit increase in pollutants. [ABSTRACT FROM AUTHOR]

In this investigation, Jatropha methyl ester (JME) [JME 20% (volume) + diesel 80% (volume)] was used to adjust the engine’s compression ratio (CR 16, 17, 17.5, and 18) and fuel injection (IT) in the range of 21–25 deg. crank angle (CA) in steps of 2 deg. before top dead center (BTDC), to identify emission profiles of the engine, where the standard CR and IT were 17.5 and 23 deg. CA BTDC. The results reveal that the CO and UHC were obtained to be as low as 0.03% vol at 75% load, CR18, and IT25, and 5 ppm at full load, CR18, and IT25 respectively. The NOx emission rallied from as low as 47 ppm at no load to as high as 1179 ppm at full load, IT of 25, and CR of 18. Whereas the NOx for diesel was 1108 ppm at full load with standard engine operation. The smoke was about 22.1% with CR18 and IT25 for JME20. However, at standard CR and IT for JME20, the smoke was 34.6%. Elevated CR of 18 and advanced IT of 25 are superior to other conditions, hence it is recommended for JME20-powered engines.Article Highlights: Jatropha seeds used were collected from the Arunachal Pradesh Forest areas of India. Sustainable decentralized power generation from JME was attained. CR of 18 and IT of 25 were superior to that of other engine conditions with JME20. [ABSTRACT FROM AUTHOR]

This review examines the potential of hydrogen, ammonia, and biodiesel as alternative fuels, focusing on spray dynamics, droplet evaporation, combustion, andemissions. Hydrogen offers superior combustion characteristics but faces challenges in NOx emissions. Strategies like non premixed direct injection, increased intake boost pressure, and low-pressure EGR are suggested for robust hydrogen combustion in compression-ignition engines. Control of hydrogen start of injection (SOI) and water injection (WI) are identified as effective techniques for reducing NOx emissions. Ammonia shows inferior combustion and higher NOx and unburned NH3 emissions in the same conditions as conventional fuels with conventional engines. Understanding ammonia spray and evaporation conditions is significant for optimizing an ammonia-air mixture and minimizing wall impingement and ammonia trap in the crevice, thereby improving combustion and emission reduction. Increasing intake pressure, injection pressure, and EG Rrate, employinga turbulent jet, and preheating ammonia improve efficiency and reduce NOx emissions. Utilizing ammonia combustion requires the implementation of after-treatment systems such as NH3 adsorber and DeNOx catalysts to mitigate unburned NH3 and NOx emissions. Biodiesel affects the fuel supply system, combustion, and emission characteristics according to its viscosity and density. Increasing injection pressure and blending with volatile fuels enhance spray and combustion. Optimum biodiesel preheating temperatures for the injection pump and injector are crucial for achieving the best pump capacity and spray formation. By utilizing biodiesel-PODE blends and investigating low-temperature biodiesel combustions, there is potential to improve thermal efficiency and PM-NOx trade-off. Therefore, carbon-neutral fuel adoption should be accelerated to mitigate CO2 emissions, highlighting the importance of combustion techniques and emissions reduction strategies. [ABSTRACT FROM AUTHOR]

The continuous monitoring of PM2.5 (including 12 metal elements) was conducted in Jinan, a city with poor air quality in China, during the 13th Five-Year Plan (2016–2020). Positive matrix factorization (PMF) was used to identify emission sources of PM2.5-bound metals, and the health risks of the metals and their emission sources were assessed. During the study period, the concentration of most metals showed a decreasing trend (except Al and Be), and a significant seasonal difference was found: winter > fall > spring > summer. The PMF analysis showed that there were four main sources of PM2.5-bound metals, and their contributions to the total metals (TMs) were dust emissions (54.3%), coal combustion and industrial emissions (22.3%), vehicle emissions (19.3%), and domestic emissions (4.1%). The results of the health risk assessment indicated that the carcinogenic risk of metals (Cr and As) exceeded the acceptable level (1 × 10−6), which was of concern. Under the influence of emission reduction measures, the contribution of emission sources to health risks changes dynamically, and the emission sources that contribute more to health risks were coal combustion and industrial emissions, as well as vehicle emissions. In addition, our findings suggest that a series of emission reduction measures effectively reduced the health risk from emission sources of PM2.5-bound metals. [ABSTRACT FROM AUTHOR]

Legal regulations for exhaust gas treatment in small‐scale combustion systems demand both emission and dust reduction. Simultaneously removing both pollutants using catalysts presents a significant challenge due to constraints on the very low allowed pressure drop over the catalyst. It can be demonstrated that the total oxidation of CO, as one of the main pollutants in the combustion of biogenic materials, in small‐scale combustion systems can be quantitatively achieved using precious metal‐based catalysts based on Pt/CeO2/TiO2. The highest CO conversion rate can be observed with a 233 cpsi honeycomb catalyst, whereas the foam ceramic catalysts with 30, 20, and 10 ppi show progressively decreasing activity. However, concerning dust reduction, it can be demonstrated that the ceramic foam with 10 ppi is superior, as evidenced in real‐world experiments conducted on an Leda Novia W small‐scale combustion device with 8 kW combustion capacity. Particle deposition on the catalysts is observed with all catalysts, whereby catalysts with small pores show rapid pore blockage. It is observed that only with the 10 ppi foam catalyst, dust deposition does not lead to pore blockage, allowing a reduction in dust of more than 50% over the measurement cycle. [ABSTRACT FROM AUTHOR]

In light of continuous advancements in science and technology, the global economy is experiencing rapid growth. However, this growth has been accompanied by significant depletion of natural resources and environmental degradation. Consequently, there is a burgeoning global emphasis on energy conservation, emissions reduction, and sustainable development. In this study, based on the Science Citation Index Expanded (SCIE) and Social Science Citation Index (SSCI) databases from 1990 to 2022, a statistical analysis of energy conservation and emission reduction in alignment with Sustainable Development Goals (SDGs)-related publications was undertaken using biblimometric methods. The findings reveal that (1) In recent years, there has been a discernible increase in global research on this subject, especially since 2009, with a sustained trend of exceeding 100 publications per annum. China prominently contributing to this domain, the proportion reached 34.2%, reflecting a growing emphasis on eco-friendly development trends. (2) Due to the burgeoning significance of energy conservation and emission reduction, there has been a notable escalation in research efforts pertaining to "Energy and Fuels," "Environmental Science" and "Green and Sustainable Science and Technology" and other related subjects. (3) Regarding the keyword analysis, "renewable energy" as the most frequently encountered term, often paired with "CO2 emissions." This association underscores the pivotal role of renewable energy technologies in advancing green development initiatives and mitigating emissions. (4) China, United States and United Kingdom occupy central positions in terms of both paper publication volume and collaborative networks, collectively accounting for about 54.7%, and these countries are pivotal contributors to the scholarly discourse on sustainable development and environmental conservation. (5) From 1990 to 2022, the top 20 cited articles predominantly address diverse sub-goals of Sustainable Development Goal 7, with a common emphasis on enhancing energy efficiency, sustainability and renewable energy. These findings furnish valuable analytical insights for subsequent researchers investigating energy conservation and emission reduction as well as sustainable development endeavors. [ABSTRACT FROM AUTHOR]

In this research study, fuel blends of pine oil and waste cooking oil biodiesel (P/WCO) were examined for combustion analysis, engine performance, and emission characteristics tests. Improved combustion and engine performance were achieved using a toroidal re-entrant combustion chamber (TCC) and hydrogen supply as a dual fuel. The combustion behavior of fuel blends and hydrogen fuel was examined by varying the engine load at a constant speed. The results revealed that significant reduction in the specific fuel consumption for rich pine oil. Thus, a slightly lesser energy share from the fuel blends and a higher energy share from the hydrogen fuel was required for the engine to maintain the same brake power. Lower viscosity, higher flash point, and presence of oxygen in the pine oil enhance the combustion rate and brake thermal efficiency. Furthermore, hydrogen induction in the engine improves the flame velocity. A lesser crevice volume in the TCC can trap the unburnt fuel which can further increase the combustion efficiency. Thus, rich pine oil with the support of hydrogen induction in TCC causes advanced ignition, improved combustion, and more heat release during the combustion. The investigation results revealed that hydrogen induction increases the heat release rate and peak pressure by 7.4% and 2.67%, respectively. Similarly, the maximum of 24.55% increase in BTE and 18.22% reduction in BSFC was observed due to a constant 10 lpm hydrogen induction. Furthermore, hydrogen fuel significantly reduces the emissions such as CO, HC, CO 2 , and smoke. However, more NO x was generated due to more heat release rate during combustion. Thus, pine oil and waste cooking oil biodiesel blends with the support of hydrogen induction in TCC improve the engine performance and mitigate the toxic pollutants and can be a suitable alternative to diesel fuel. • Combustion effects of pine oil and waste cooking oil biodiesel blends were examined. • The influence of hydrogen addition in dual fuel mode is highlighted. • Impact of the toroidal re-entrant combustion chamber concerning BTE, BSFC, and emissions was discussed. • The energy share between biodiesel and hydrogen is discussed. [ABSTRACT FROM AUTHOR]

The maritime industry, responsible for moving approximately 90% of the world's goods, significantly contributes to environmental pollution, accounting for around 2.5% of global greenhouse gas emissions. This review explores the integration of artificial intelligence (AI) in promoting sustainability within the maritime sector, focusing on shipping and port operations. By addressing emissions, optimizing energy use, and enhancing operational efficiency, AI offers transformative potential for reducing the industry's environmental impact. This review highlights the application of AI in fuel optimization, predictive maintenance, route planning, and smart energy management, alongside its role in autonomous shipping and logistics management. Case studies from Maersk Line and the Port of Rotterdam illustrate successful AI implementations, demonstrating significant improvements in fuel efficiency, emission reduction, and environmental monitoring. Despite challenges such as high implementation costs, data privacy concerns, and regulatory complexities, the prospects for AI in the maritime industry are promising. Continued advancements in AI technologies, supported by collaborative efforts and public–private partnerships, can drive substantial progress towards a more sustainable and efficient maritime industry. [ABSTRACT FROM AUTHOR]

The newly updated nationally determined contributions (NDCs) outline a carbon reduction trajectory capable of achieving the 2 ℃ temperature control target stipulated by the Paris Agreement, marking a milestone in global efforts to combat climate change. However, existing literature lacks research on the economic and energy impact effects of implementing the updated NDCs. In this context, this study utilizes the Global Dynamic Computable General Equilibrium Model (GDyn-E) to predict and compare the dynamic impacts of the global joint implementation of the updated NDCs on medium to long-term economic growth, as well as the level of energy dependence in major countries and regions like China. The findings show that: ① China's implementation of its new NDC targets, namely the ‘dual carbon’ goals, is outstanding both in terms of relative and absolute emission reductions, positioning it alongside developed economies such as the United States and the European Union to lead global carbon reduction efforts and make significant contributions to global climate governance. ② The economic impacts of the global joint implementation of the updated NDCs would demonstrate strong regional heterogeneity. The Chinese economy would experience minimal negative impacts, with an actual GDP loss rate ranging from approximately 0.27% to 1.12% by 2050. The United States and the European Union would also display good economic resilience, but less developed regions and net fossil energy exporting countries would face more severe economic losses. ③ Net fossil energy-importing countries could reap the synergistic benefits of carbon reduction and enhanced energy independence, but net fossil fuel-exporting countries would see a decline in export revenues. Due to reduced fossil energy imports and increased exports of renewable electricity, China's energy external dependence would continuously decrease after 2030. Simultaneously, the share of non-fossil energy would increase significantly, and the diversification of fossil energy import sources would help enhance China's overall energy security. This study points out that, in the process of implementing the ‘dual carbon’ goals, China should timely observe and urge the fulfillment of NDCs by all countries, actively provide green aid, strengthen international cooperation on climate change, and expand energy trading partners to promote the development of clean energy trade. The study reveals the significant impacts of the global joint implementation of the updated NDCs on the economic development and energy external dependence of major countries and regions like China, providing policy guidance for China in coordinating carbon reduction, economic development, and energy security while deeply engaging in global climate governance. [ABSTRACT FROM AUTHOR]

A significant decrease in surface PM2.5 concentrations has been reported since the implementation of the Air Pollution Prevention and Control Action Plan in 2013. In this study, we use the GEOS-Chem model to simulate the trend in surface PM2.5 pollution in China from 2013 to 2017, as well as the relative contributions of emission reduction and meteorology. The simulated decline rate averaged over monitoring sites in China is around −4.7 μg m−3 yr−1 in comparison with the value of −6.4 μg m−3 yr−1 from observations. The model also captures the variations over different regions, with r in the range of 0.85–0.95. Based on the sensitivity tests against emissions and meteorology, the study finds that the decline in PM2.5 concentrations is mainly driven by the reduction in anthropogenic emissions. The variation in open biomass burning (OBB) is not significant, except in Northeast China (NEC) and Pearl River Delta (PRD), where the changes originated from OBB are 40% and 30% of those associated with anthropogenic emission reductions. Changes in meteorology from 2013 to 2017 led to significant increases in PM2.5 concentrations in most areas in China, except in NEC. The increase attributed to meteorology, to a large extent, could be explained by the significant decrease in surface wind speed (WS) and planetary boundary layer height (PBLH) between 2013 and 2017, combined with their negative correlation with PM2.5. The decrease in PM2.5 concentrations in NEC, on the other hand, could be explained by the significant decrease in relative humidity (RH) there combined with the positive correlation of RH with PM2.5, while the changes in WS and PBLH there are relatively small compared with other areas. The change in meteorology, therefore, hinders the improvement of air quality via emission controls in most of China. In Sichuan Basin (SCB), the increase due to meteorology almost compensates for the decrease associated with emission reduction, leading to the least change in PM2.5 concentrations, although the decrease due to emission controls is the largest compared with other areas. [ABSTRACT FROM AUTHOR]

In modern times, customers are increasingly aware of the environmental risks posed by the premature expiration of smart products. To safeguard the environment, companies have embraced green technology when procuring products. As a result, it is challenging for business managers to capture the market by offering the best quality products at a reasonable price, regardless of the economic situation. This paper presents a production model incorporating reverse logistics to identify defective products. The model involves learning through production and utilizes green technologies. Additionally, a portion of the assembled products is remanufactured after being received from consumers. The remanufactured items are screened and distributed to markets. Both new and remanufactured products are sold to the market based on their quality in the first and second markets, respectively. To reduce product spoilage, manufacturers employ green technology like liquid cooling technology. The numerical results demonstrate that by investing in liquid cooling technology, the production store can reduce spoilage items by 8.50%, a positive environmental outcome regarding waste reduction, and due to the learning effect, the total cost can decrease by 1.44%. The paper includes numerical and sensitivity analyses accompanied by graphs. [ABSTRACT FROM AUTHOR]

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The Po Valley stands out as one of the most urbanized and industrialized regions in Europe. For decades, it has been grappling with the impact of human exposure to fine particulate matter (PM2.5). The Lombardy Region in northern Italy, a key area within the Po Valley, experiences a complex interplay of main emission precursors (NH3, NOx, and SOx), leading to the formation of secondary inorganic aerosols. In this paper, we investigate the effects of reducing NH3, NOx, and SOx emissions, individually and in combination, on PM2.5 concentrations in the Lombardy Region. Our analyses employ the operational Air Quality model, used daily by ARPA Lombardia. The focus of the study is wintertime period (1 January–31 March), recognized as the most challenging period of the year due to strong correlations between NH3, PM10, (NH4)NO3, and (NH4)2SO4 concentrations and peaking days of ammonia emissions from slurry spreading. Our results reveal that, during wintertime emission reductions, (a) PM2.5 concentration changes exhibit linearity within 25% reduction of precursors, with non-linearities increasing as precursors reductions surpass this threshold; (b) the NOx-sensitive areas extend spatially up to 50% reductions and localize in areas with higher NH3 emissions; (c) NH3-sensitive areas are concentrated in densely urbanized regions of the Lombardy Region; and (d) sensitive chemical regimes are mixed, and it is more effective to reduce both NH3 and NOx rather than SOx (emissions of which are not abundant). Final discussions, considering furtherly both summertime and yearly simulations, underscore the significance of focusing on wintertime. PM2.5 responses to precursors display significant spatial variations compared to summertime, where NOx-sensitive areas predominate. These findings provide valuable insights into reducing PM2.5 concentrations, assisting air quality policymakers in understanding the impacts of precursor emissions on PM2.5 levels during wintertime. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the emissions of greenhouse gases (GHGs) stemming from the sludge treatment sector in China and to investigate the feasibility of novel technologies in curtailing these emissions, with the aim of fostering sustainable sludge management methodologies. Employing a life-cycle assessment (LCA) methodology, the research computed the comprehensive GHG emissions resulting from sludge treatment, taking into consideration diverse elements such as treatment techniques (e.g., landfills, incineration, and land application) and the geographical variations among China's 660 municipalities. Findings indicate that the total amount of GHG emissions from sludge treatment amounted to 18.54 Mt CO2-eq in 2017, with incineration registering the highest emissions (10,011.53 kg CO2-eq/t dry sludge (DS)), followed by landfills (717.51 kg CO2-eq/t DS) and land application (276.41 kg CO2-eq/t DS). The geographical dispersion of emissions characteristics reveal notable regional disparities, with the top 1% of cities responsible for 34.2% of the overall emissions. The concentration of emissions in the top 1 percent of cities underscores the necessity for tailored mitigation measures that consider localized sustainable development challenges. Principal component analysis (PCA) demonstrates that economic determinants and treatment scales exert substantial influence on emissions, underscoring the imperative of aligning Sustainable Development Goals (SDGs) with economic advancement. To curtail the carbon footprint associated with sludge treatment and enhance sustainability, the study evaluated the emission mitigation potential and expenses of diverse technologies, encompassing thermal conversion, anaerobic digestion, hydrothermal treatment, and wet oxidation. These technologies have the capacity to slash GHG emissions by 0.09–0.46 t CO2-eq/t DS in comparison to traditional approaches, while concurrently advancing resource recuperation and principles of circular economy. For instance, gasification could diminish GHG emissions by 0.33–0.46 t CO2-eq/t DS, whereas anaerobic digestion could yield reductions of 0.09–0.30 t CO2-eq/t DS. The implementation of these innovative technologies across 660 Chinese municipalities could potentially curtail total GHG emissions from sludge treatment by 15–40%. Nevertheless, further enhancements are imperative to refine their environmental and economic efficiency and guarantee enduring sustainability. By deploying these technologies and embracing optimization tactics, China's sludge treatment sector can make a substantial contribution towards attaining national carbon neutrality objectives and advancing sustainable development. [ABSTRACT FROM AUTHOR]

This study reviews the steps Canada is taking to address sustainable decarbonization in the context of carbon capture. This work also presents a new optimal framework for national optimal deployment in need of strategic carbon capture implementation. This framework considers external environmental and social considerations often missing from implementation frameworks, which will aid policy makers in more well‐rounded deployment decisions. Thus far, Canada's carbon projects have captured a total of 36.3 Mt of CO2 which has cost over $2.7 billion to implement. The Canadian case study utilizing the proposed optimal planning strategy shows that implementation of 58 post‐combustion carbon capture (PCC) plants located in seven provinces (Alberta, British Columbia, New Brunswick, Nova Scotia, Ontario, Quebec, and Saskatchewan) would result in Canada meeting the national targets. This implementation includes 16 plants removing emissions from the Electricity sector, 16 from the Heavy Industry sector, and 26 from the Oil and gas sector resulting in new emissions levels of 11.82 MtCO2, 27.63 MtCO2, and 107.01 MtCO2 in each sector, respectively. Additional case studies examined the impact of Alberta's emissions and varying the national targets resulting in different optimal implementations plans. Through a sensitivity analysis on these targets, it was determined that plant distribution is heavily dependent on provincial energy and CO2 transport prices. Additionally, if Alberta were to reduce their GHG emissions by 50% through alternative sustainable methods, only 35 PCC plants would be required to meet national targets. This framework provides a sustainable tool for decision‐makers to accelerate decarbonization. [ABSTRACT FROM AUTHOR]

In this study, greenhouse gas emissions caused by natural gas, electricity and diesel fuel consumed within the boundaries of Kütahya 30 August Organized Industrial Zone were calculated and studies were explored for reduction activities. Within the scope of ISO 14064-1 Guidelines and Features Standard for Calculation and Reporting of Greenhouse Gas Emissions and Removal at the Establishment Level” and “ISO 14067 Product Carbon Footprint Calculation Standard”, the amount of greenhouse gases released into the atmosphere was calculated by using the data recorded by the enterprises on a yearly basis. While the direct emissions from natural gas was calculated as 105394.84 tCO2e in 2019, these emissions decreased in 2020 and reached 2019 level again in 2021. Indirect emissions from imported electricity were 64269.12 tCO2e in 2019, while electricity-related emissions increased in 2020 and 2021. Direct emissions from diesel are considerably lower than those from natural gas and electricity in terms of quantity. However, while the emissions from diesel fuel was 74.11 tCO2e in 2019, these emissions decreased by 75.5% in 2020 and reached 29.49 tCO2e in 2021. A large part of the greenhouse gas generated due to both electricity and natural gas consumption originates from an organization operating in the field of tile-ceramic manufacturing and an organization operating in the field of paper-corrugated cardboard manufacturing. There are many organizations in different fields of activity in organized industrial zones. The study has shown that greenhouse gas emissions must be monitored in these regions and it is necessary to determine the source of greenhouse gas emissions, otherwise the proposed reduction methods will not be very effective.

This paper investigates how variations in aviation carbon pricing influence the network choices of airlines and social planner. Beyond the traditional direct-flight (DF) network, hub-and-spoke (HS) network and mixed (MX) network, we incorporate the 2-hub (2 H) network into our analysis. The findings reveal that as carbon pricing costs increase, the optimal network configuration for airlines progresses sequentially through 2 H, MX and DF. This suggests that due to horizontal product differentiation, the inclusion of 2 H in the model renders the HS network—which is widely utilized by numerous major airlines—no longer the optimal choice for airlines. From the perspective of social planner, the optimal network configuration undergoes a progression from HS, 2 H, HS, MX, DF, MX to DF as carbon pricing costs rise. While the HS network may not align with the optimal choice for airlines, it has the potential to be the socially optimal network. Furthermore, the transition of socially optimal networks exhibits discontinuities, resulting in significant deviations from the network decisions made by airlines. Overall, this paper broadens the scope of network choices available to airlines by incorporating the 2 H network and offers theoretical insights for policy formulation by both airlines and society within the context of aviation carbon offset.

[Display omitted] • The growth of energy, primary and secondary industries, and GDP per capita lead to an increase in CO 2 emissions. • The increase of the urbanization rate and natural gas consumption will lead to a downward trend of emissions. • The adjacent accumulation multivariable grey model has better stability. Carbon dioxide (CO 2) emissions, the primary greenhouse effect catalyst, command global attention due to associated environmental challenges. Urgent carbon reduction is imperative, particularly with scholarly discourse emphasizing the criticality of peak emissions and carbon neutrality. Accurate CO 2 emission prediction holds immense importance for shaping effective management policies aimed at emission reduction and environmental mitigation. This study introduces an enhanced multivariable grey prediction model (AGMC(1,N)), utilizing the particle swarm optimization (PSO) algorithm based on artificial intelligence to determine its optimal order. Rigorous analysis, including a disturbance bound classification discussion, validates the superior stability and outstanding predictive capability of the AGMC(1,N) model, as exemplified in a detailed case study. Applying the AGMC(1,N) model to forecast CO 2 emissions in the Beijing-Tianjin-Hebei region and Shanxi Province reveals a correlation between energy, primary and secondary industry growth, GDP per capita, and increased emissions, while rising urbanization and natural gas consumption correlate with emission decline. The study concludes with actionable proposals derived from predictive insights, providing valuable support for decision-making by management departments focused on emission reduction. [ABSTRACT FROM AUTHOR]

Abstract Higher concentrations of air pollutants, such as nitrogen dioxide (NO $$_\text {2}$$ 2 ) and particulate matter (PM), are observed in streets compared to the urban background. These concentrations could be predominantly attributed to road traffic, which remains an important source despite relentless efforts. In this study, performed over the Paris area, the impacts of the evolution of the fleet composition on urban air quality down to the street scale is assessed with two scenarios assuming the introduction of very-low-emission vehicles. Exhaust emission factors for these vehicles are based on the improvement of engine and after-treatment technologies, leading to factors lower than those proposed for the European emission standard Euro 7. Using the year 2014 as the baseline, very-low-emission vehicles are introduced up to the year 2030 for the Paris region. NO $$_\text {2}$$ 2 emissions are thus reduced by 68 % in streets, and concentrations by 53 %. However, PM concentration reduction is limited to 18 % in streets as non-exhaust emissions from tyre and brake wear and road abrasion are preponderant. PM emissions from non-exhaust sources represent 59 % of the total road-traffic emission of PM in 2014 and 89 % in 2030. Non-regulated pollutant concentrations are also reduced, by 42 % for black carbon and 30 % for organic matter. Considering only very-low-emission and electric vehicles in the fleet further reduce NO $$_\text {2}$$ 2 emissions and concentrations by 99.5 % and 80 % respectively. PM concentrations are only reduced by 22 %. This study highlights the high reduction potential of NO $$_\text {2}$$ 2 concentrations with very-low-emission and electric vehicles, because of reduction of exhaust emissions. However, difficulties remain to reduce PM concentrations in urban areas, with the large majority of PM traffic emissions coming from non-exhaust sources.

This study provides a comprehensive overview of the challenges to achieving carbon neutrality at the county level in China and offers targeted recommendations, laying the groundwork for future specialized research in this area. A total of 283 relevant studies (2004–2023) were analyzed to assess county-level carbon emissions through three phases: bibliometric analysis, frontier analysis, and future prospects. Bibliometric findings reveal that publication trends were largely influenced by domestic and foreign policies. Keyword cluster discerns ten primary themes, ranging from conceptual frameworks to research methodologies. The frontier analysis of the literature highlights the leading research areas, which include carbon neutrality pathway, driving factors, spatiotemporal variation of carbon emissions, the co-effects of pollutants and carbon reduction, and carbon emissions in China's rural areas. Drawing from the results of bibliometric and frontier analyses, this study elucidates the recommendations for achieving carbon neutrality at the county level from three perspectives: effective regional policy guidance, emphasis on ecological conservation, and the deployment of advanced carbon reduction and sequestration technologies. This study enriches the body of knowledge on carbon emissions at the county level and holds significant implications for China's comprehensive push towards achieving its carbon neutrality objectives.

In the presented research, the authors dealt with the specific properties of the combustion process of dimethyl ether (DME) in a combustion car (Volkswagen Golf IV) engine AJM 1.9 TDI PDE made by Volkswagen factory. Dimethyl ether is an alternative fuel produced most often from natural gas, which can be used in compression ignition engines as a single fuel or co-burned with diesel oil. This work describes the impacts of using exhaust gas recirculation system and various diesel to DME substitution ratios from 0% to approximately 25% (on an energy basis), on the combustion process in a dual-fuel diesel engine. The engine has been modified so that DME fuel is introduced into the intake manifold just before the intake valves. The diesel fuel supply system, operation algorithms of the engine electronic control unit and other engine elements were left unchanged as it was built by the manufacturer.

Reducing greenhouse gas (GHG) emissions and quantifying the carbon footprint (CF) of rice-cropping systems in the context of food security is an important step toward the sustainability of rice production. Exploring the key factors affecting emission reduction in rice production is important to properly evaluate the impact of China's rice-cropping systems on global climate change. This review provides an overview of the direct and indirect CF in rice-cropping systems; analyzes the influencing factors in terms of rice-based cropping systems, varieties and agronomic practices; and proposes mitigation strategies. Different studies have shown that direct and indirect GHG emissions in rice-based cropping systems accounted for 38.3 to 95.5% and 4.5 to 61.7% of total emissions, respectively. And the CFs of ratoon rice, rice-wheat, rice-maize, rice-rapeseed, and rice-fish systems ranged from 316,9 kg CO2-eq kg-1 to 258,47 kg CO2-eq kg-1, which are lower than that in a double-rice planting system. High-yielding rice, drought-resistant rice, and other hybrids can mitigate GHG emissions from paddy fields by 3.7 ~ 21.5%. Furthermore, organic matter, water, tillage, straw incorporation, conservation tillage, reduced nitrogen fertilizer use, and added biochar and methane inhibitors could reduce emissions. Therefore, through reasonable agronomic measures, variety selection and optimal layout of rice-based rotation systems, the carbon neutral rate of rice production can be improved to help the national carbon sequestration and emission reduction target. [ABSTRACT FROM AUTHOR]

Incorporating renewables in the power grid presents challenges for stability, reliability, and operational efficiency. Integrating energy storage systems (ESSs) offers a solution by managing unpredictable loads, enhancing reliability, and serving the grid. Hybrid storage solutions have gained attention for specific applications, suggesting higher performance in some respects. This article compares the performance of hybrid energy storage systems (HESSs) to a single battery, evaluating their energy supply cost and environmental impact through optimization problems. The optimization model is based on a MILP incorporating the energy and degradation terms. It generates an optimized dispatch, minimizing cost or environmental impact of supplying energy to a generic load. Seven technologies are assessed, with an example applied to an industrial site combining a vanadium redox flow battery (VRFB) and lithium battery considering the demand of a local load (building). The results indicate that efficiency and degradation curves have the highest impact in the final costs and environmental functions on the various storage technologies assessed. For the simulations of the example case, a single system only outperforms the hybrid system in cases where lithium efficiency is higher than approximately 87% and vanadium is lower approximately 82%. [ABSTRACT FROM AUTHOR]

Greenhouse gases refer to gases that can absorb long-wave radiation in the earth's atmosphere and cause atmospheric temperature to rise, among which carbon dioxide, methane, nitrous oxide and fluorine are the gases that have the most prominent impact on climate change. Greenhouse gas emissions from animal husbandry account for a large proportion of the total global emissions. Therefore, in order to reduce the impact of animal husbandry on climate change, it is particularly important to control greenhouse gas emissions from cowshed. At present, there are two main ways to control greenhouse gas emissions from cowshed: Improving the production mode and management mode of animal husbandry to reduce greenhouse gas generation, control greenhouse gas emissions through technical means. This paper explains the toxic effect of greenhouse gases emitted by cattle in cowshed, emphatically analyzes the related factors affecting greenhouse gas emissions and its control methods, discusses various greenhouse gas emission reduction control measures from the perspectives of feed composition and additive regulation, adsorbent placement in the cowshed environment, and environmental optimization outside of the cowshed, and analyzes the advantages and existing problems of the existing technologies, to provide references for promoting environmentally friendly, sustainable scientific livestock and poultry farming practices. [ABSTRACT FROM AUTHOR]

Higher concentrations of air pollutants, such as nitrogen dioxide (NO 2 ) and particulate matter (PM), are observed in streets compared to the urban background. These concentrations could be predominantly attributed to road traffic, which remains an important source despite relentless efforts. In this study, performed over the Paris area, the impacts of the evolution of the fleet composition on urban air quality down to the street scale is assessed with two scenarios assuming the introduction of very-low-emission vehicles. Exhaust emission factors for these vehicles are based on the improvement of engine and after-treatment technologies, leading to factors lower than those proposed for the European emission standard Euro 7. Using the year 2014 as the baseline, very-low-emission vehicles are introduced up to the year 2030 for the Paris region. NO 2 emissions are thus reduced by 68 % in streets, and concentrations by 53 %. However, PM concentration reduction is limited to 18 % in streets as non-exhaust emissions from tyre and brake wear and road abrasion are preponderant. PM emissions from non-exhaust sources represent 59 % of the total road-traffic emission of PM in 2014 and 89 % in 2030. Non-regulated pollutant concentrations are also reduced, by 42 % for black carbon and 30 % for organic matter. Considering only very-low-emission and electric vehicles in the fleet further reduce NO 2 emissions and concentrations by 99.5 % and 80 % respectively. PM concentrations are only reduced by 22 %. This study highlights the high reduction potential of NO 2 concentrations with very-low-emission and electric vehicles, because of reduction of exhaust emissions. However, difficulties remain to reduce PM concentrations in urban areas, with the large majority of PM traffic emissions coming from non-exhaust sources. [ABSTRACT FROM AUTHOR]

Nowadays, environmental issues have received increasing attention from experts. The main cause is the increase of carbon emissions in the atmosphere, so it is urgent to reduce carbon emissions. In order to establish the optimal pricing strategy as well as the emission reduction effort strategy for companies who produce and sell low carbon products, this paper proposes an optimal control model for low carbon products. The reduction of the carbon emission for the product is described dynamically by a differential equation, and the analytical expressions of the optimal pricing and the emission abatement strategies are derived using the Pontryagin's maximum principle. Finally, the numerical experiments are used to explain the results obtained. The results show that companies producing and selling low-carbon products must pay more attention to the amount of carbon emission reduction in their products, and make more efforts to reduce emissions in order to make more profits. Additionally, the parametric analysis shows that expanding market size and reducing inventory depletion can be equally helpful in shortening the sales cycle and boosting profits. [ABSTRACT FROM AUTHOR]