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• Estimates of modeled CH 4 emission (E) data for 1,325 U.S. landfills were reviewed. • Operators use two methods to estimate E from landfills with a gas collection system. • First-order decay (FOD) method shows increasing emissions. • Collection efficiency assumption method shows decreasing emissions. • FOD method shows some agreement to remotely sensed national estimates. As part of its commitment to the United Nations Framework Convention on Climate Change, the U.S. annually develops a national estimate of methane emissions from municipal solid waste (MSW) landfills by aggregating activity data from each facility. Since 2010, the U.S. has reported a 20 % decrease in MSW landfill emissions despite a 21 % increase in tons disposed. Operator-submitted data were investigated to understand the causes of this decline. In the U.S., operators of landfills with a gas collection and control system (GCCS) calculate their facility's emissions via two separate approaches – (1) first-order decay (FOD) and (2) collection efficiency assumption (CEA) − and select either result to feed into the annual inventory. The FOD model predicts methane generation proportional to waste disposal and that approach calculated a 19 % increase in total methane generated from 2010 to 2022, whereas generation via the CEA approach decreased by 8.9 %. The amount of measured methane collected has increased 7.5 % for the same years. Discrepancies between the two models' generated methane, assumed gas collection efficiencies, and oxidized methane compound into substantive differences in national estimates. Operators more frequently select the CEA method, which results in decreased national estimates. If only the FOD method was used, U.S. MSW landfill emissions would be 1.3-1.7 times greater than current estimates which is similar to recent extrapolations from remote sensing campaigns in the U.S. Both models contain parameters with large inherent uncertainty. Without measurement methods that continuously quantify both point-source and diffuse emissions, an assessment of either equation's accuracy cannot be made. [ABSTRACT FROM AUTHOR]

The present work aims to find a viable substitute fuel for diesel and control pollutants from compression ignition engines. Therefore, in the present investigation, an attempt has been made to study the effect of 20% proportion of five different biodiesel diesel blends in diesel engine. The 20% proportion of biodiesel such as Jatropha, Pongamia, Mahua, Annona and Nerium and 80% of diesel is denoted as J20, P20, M20, A20 and N20 are used in the present investigation. The experimental results showed that the different biodiesel blends' brake thermal efficiency is slightly lower compared to neat diesel fuel. However, the N20 blend has shown improvement in performance and reduction in exhaust emissions compared to other biodiesel diesel blends. From, the experimental work, it is found that biodiesel can be used up to 20% and 80% of a diesel engine without any major modification. [ABSTRACT FROM AUTHOR]

The experimental investigation aimed to determine how the use of biodiesel derived from dill and cresson oil affected the performance of semi-industrial burners. Furthermore, an investigation will be conducted to assess the combustion properties of different blends of biodiesel, specifically B10, B20, B40, and B60. The study looks at biodiesel's chemical makeup, physical properties, and how it works in the system that moves it to the burner and the burner simulator's burning process. Biodiesel exhibits comparable qualities to conventional diesel oil, enabling the possibility of blending it to achieve the desired ratio. The results suggest that increasing the percentage of biodiesel leads to a reduction in flame distance and a rise in flame temperature. Furthermore, the complete combustion of the fuel is responsible for the brilliant and transparent flame. Additionally, using dill and Cresson fuels that come from biodiesel raises the average flame temperature by about 17% and 16.1%, respectively, compared to regular diesel fuel. [ABSTRACT FROM AUTHOR]

The analysis of environmental impacts throughout the entire process of coal-fired power plants is imperative to implement effective measures for controlling and reducing pollutant emissions. However, there is still limited research focusing on the cradle-to-gate stage in the life cycle of coal-fired power plants and their environmental impact. This study employs a life cycle assessment (LCA) methodology to assess the environmental impacts of coal-fired power plants in South Sumatra. The primary environmental impact categories of primary emissions include CO2, SO2, NOx, and CH4. The most significant environmental impacts arise from CO2 emissions, notably 98.46% from land clearing and preparation and 86.74% from overburden removal and coal extraction. These stages primarily contribute to global warming throughout the cradle-to-gate process. Sulfur dioxide emissions from land clearing activities are the main contributor to acid rain, followed by overburden removal and coal extraction (96.51%) and coal stockpiling (1.48%), which also play a role. The release of NOx from land clearing and preparation, overburden removal, and coal stockpiling contributes to the potential for eutrophication. Land clearing and preparation have a significant impact on global warming during the coal mining and distribution stages. Practical measures such as enhancing emission reduction facilities and increasing pollutant emission standards for each process are necessary to promote environmentally friendly coal-fired power plants. [ABSTRACT FROM AUTHOR]

Synthesis and characterization of two curcumin analogues BAA and Br‐AA via a condensation reaction was reported. Both the synthesized organic luminophores exhibited aggregation‐induced emission (AIE) with bright yellow and green emission respectively. Increase in the water% enhanced the emission by both the compounds confirmed the AIE property. A detailed study of latent fingerprints visualization was also carried out for both the analogues. Both the compounds showed good to normal capability to develop latent fingerprints (LFPs). Compound BAA performed better as a fluorescent material to develop LFPs compared to Br‐AA. The LFPs developed were analyzed to obtain 1–3 level of fingerprint patterns under UV 365 nm illumination. The LFPs developed using BAA exhibited excellent efficiency, sensitivity, high contrast with low background interreference. All three levels of fingerprint patterns were identified by BAA. However, Br‐AA showed inability to develop high clarity images of latent fingerprints. The solid‐state emission nature of the analogues was also evaluated from their emission spectra and CIE coordinates were found to be were (0,187, 0.518) and (0.265, 0.484) for BAA and Br‐AA respectively. [ABSTRACT FROM AUTHOR]

This paper analyses the intertwined impacts of the 2018 US sanctions on Iran and the COVID-19 pandemic (as examples of unplanned international conflicts and global crises) on the source and extent of air pollution in Tehran, the capital of Iran. The impacts are parametrized using the levels of criteria air pollutants (CAP) for 5 years (2015–2020), which were previously deweathered using the promising machine learning technique of Random Forest (RF). The absolute principal component scores-multiple linear regression (APCS-MLR) method and the bivariate polar plot (BPP) technique are used here to analyze the source apportionment profile of the city for the business as usual (BAU; 2015 to 2018), sanctions (2019), and COVID-19 and sanctions (2020) intervals. The results show the severe impact of the 2018 US sanctions on Tehran's air quality (AQ); O3, NO2, CO, PM2.5, and PM10 levels increased by 117%, 55%, 20%, 35%, and 10%, respectively, while SO2 levels decreased by 30%. The sanctions also triggered a number of events, such as the disruption of the high-grade fuel supply chain and the Mazut crisis, which directly or indirectly accelerated the photochemical production of local tropospheric ozone to some extent. Sanctions also disrupted Tehran's AQ response to the pandemic, with CAP levels decreasing by only 2–7% during the pandemic. The ozone and PM10 BPPs show that the source apportionment profile of the city is dominated by local anthropogenic emission sources, especially urban transport, after the sanctions and the pandemic. Results also show that the impact of soft wars, such as the US sanctions against Iran, on urban air quality degradation is much stronger than that of hard wars, such as the Russia-Ukraine war. [ABSTRACT FROM AUTHOR]

With a specific end goal to take care of the worldwide demand for energy, broad research is done to create alternative and cost-effective fuel. The fundamental goal of this examination is to investigate the performance, emissions and vibration characteristics of a single cylinder four stroke diesel engine, working in dual fuel mode with biodiesel of Karanja oil ((BKO) as a renewable fuel and hydrogen (H 2) as gaseous fuel on low (2%), intermediate between medium-high (53%) and high (69%) load conditions. Biodiesel of Karanja oil as 20% biodiesel and 80% diesel known as BKO20, while 30% biodiesel and 70% diesel known as BKO30. With 25% introduction of gaseous fuel (H 2) and biodiesel (10%–40%) along with diesel showed an increase in brake thermal efficiency (BTE), 85.23%, 10.62% and 19.4% respectively as compared to parent diesel fuel operation. As far as emission is concerned, oxides of nitrogen (NO x) decreased on higher load conditions with a variation of biodiesel (10%–50%) in comparison to low load condition. However, the formation of monoxide (CO), carbon dioxide (CO 2) and un-burnt hydrocarbon (HC) decreases along with BKO50 using 25% hydrogen fuel substitution at high (69%) load conditions. • H 2 (25%) along with Karanja oil (40%) substituted by 65% diesel fuel. • Brake thermal efficiency (85.23%) optimum with Karanja oil (10%) by H 2 (25%) fuel. • Emission, combustion and its performance formed superior features. • NO x formation decreased as biodiesel substitution increases up to 50%. [ABSTRACT FROM AUTHOR]

Copyright of Environmental & Social Management Journal / Revista de Gestão Social e Ambiental is the property of Environmental & Social Management Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

South Africa is an energy-intensive developing country in Africa and ranked as the 1st and 14th emitter of greenhouse gas (GHG) in Africa and the world, respectively. The abundance and availability of coal in South Africa make it the mainstay primary source of energy contributing 56% of national total GHG emissions. This paper focused on the duo of energy generation and emission associated with coal processing and utilization in South Africa, and the urgent need to advance coal processing technologies marked by high carbon footprints in consonance with the sustainable development goals. Different gasification techniques and their performances have been compiled and discussed. The economic, environmental impact, energetic, and exergetic characteristics of existing hydrogen production technologies for renewable and non-renewable energy sources have been examined along with hydrogen production from plasma gasification of coal. Hydrogen production via coal or coal/biomass plasma gasification technology (nuclear-, wind-, PV solar-, and concentrated solar power-driven) in addition to carbon capture technology for transforming the captured CO 2 into value-added products appears to be the most viable option to considerably reduce emissions and meet the energy demand of South Africa. This proposed technology can be pivotal to achieving a low-carbon economy (medium-term) and transition to hydrogen economy (long-term) as championed by the global sustainable development agenda. Conclusively, hydrogen (stored in different forms e.g., liquid hydrogen, ammonia, and organic hydride) seems to find more applications (in the space industry, transport, energy storage, defense industry, etc.) than coal owing to its immediate use in distribution/demand centers and remote areas. • Coal is the primary energy source of South Africa and key driver of national CO 2 emissions. • Traditional coal gasification technologies are marked by high CO 2 emissions. • Coal plasma gasification technology is a viable option for low-carbon energy economy. • Hydrogen production via coal or coal/biomass plasma gasification technology leads to zero-carbon economy. • This immensely supports the drive towards attaining the sustainable development goals. [ABSTRACT FROM AUTHOR]

Despite the extensive research on biodiesels, further investigation is warranted on the impact of compression ratios on emissions and engine performance. This study addresses this gap by evaluating the effects of increasing the engine's compression ratio on engine performance metrics—brake-specific fuel consumption (BSFC), power, torque, and exhaust gas temperature—and emissions—unburnt hydrocarbons (HCs), carbon dioxide (CO2), carbon monoxide (CO), nitrogen oxides (NOx), and oxygen (O2)—when fueled with a 20% blend of waste cooking oil biodiesel (WCB20) and petroleum diesel (PD) under various operating conditions. The viscosity of the prepared fuels was measured at 25 °C and 40 °C. Experiments were conducted on a single-cylinder diesel engine under wide-open throttle conditions at three different speeds (1400 rpm, 2000 rpm, and 2600 rpm) and two compression ratios (16:1 and 18:1). The results revealed that at a lower compression ratio, both WCB20 and petroleum diesel exhibited reduced BSFC compared to higher compression ratios. However, increasing the compression ratio from 16:1 to 18:1 significantly decreased HC emissions but increased CO2 and NOx emissions. Engine power increased with engine speed for both fuels and compression ratios, with WCB20 initially producing less power than diesel but surpassing it at higher compression ratios. WCB20 demonstrated improved combustion quality with lower unburnt hydrocarbons and carbon monoxide emissions due to its higher oxygen content, promoting complete combustion. This study provides critical insights into optimizing engine performance and emission characteristics by manipulating compression ratios and utilizing biodiesel blends, paving the way for more efficient and environmentally friendly diesel engine operations. [ABSTRACT FROM AUTHOR]

Natural gas (NG) is favored for transportation due to its availability and lower CO2 emissions than fossil fuels, despite drawbacks like poor lean combustion ability and slow burning. According to a few recent studies, using hydrogen (H2) alongside NG and diesel in Tri-fuel mode addresses these drawbacks while enhancing efficiency and reducing emissions, making it a promising option for diesel engines. Due to the importance and novelty of this, the continuation of ongoing research, and insufficient literature studies on HNG–diesel engine emissions that are considered helpful to researchers, this research has been conducted. This review summarizes the recent research on the HNG–diesel Tri-fuel engines utilizing hydrogen-enriched natural gas (HNG). The research methodology involved summarizing the effect of engine design, operating conditions, fuel mixing ratios and supplying techniques on the CO, CO2, NOx and HC emissions separately. Previous studies show that using natural gas with diesel increases CO and HC emissions while decreasing NOx and CO2 compared to pure diesel. However, using hydrogen with diesel reduces CO, CO2, and HC emissions but increases NOx. On the other hand, HNG–diesel fuel mode effectively mitigates the disadvantages of using these fuels separately, resulting in decreased emissions of CO, CO2, HC, and NOx. The inclusion of hydrogen improves combustion efficiency, reduces ignition delay, and enhances heat release and in-cylinder pressure. Additionally, operational parameters such as engine power, speed, load, air–fuel ratio, compression ratio, and injection parameters directly affect emissions in HNG–diesel Tri-fuel engines. Overall, the Tri-fuel approach offers promising emissions benefits compared to using natural gas or hydrogen separately as dual-fuels. [ABSTRACT FROM AUTHOR]

Homogeneous charge-induced ignition (HCII), which uses trace diesel to induce the ignition of gasoline pre-mixture, is characterized by rapid lean combustion and is generally regarded as efficient, clean and controllable. In this paper, a conventional diesel engine has been modified to run all cylinders in HCII mode and the influence of diesel injection pressure (DIP) on overall engine performance was experimentally studied. Results show that the increase of DIP can expand the ignition area of gasoline and enlarge the premixed combustion ratio of diesel, thus promoting rapid combustion and improving brake thermal efficiency. The increase of DIP is beneficial to the control of ignition time and combustion phase, thus reducing the cyclic fluctuation. The increase of DIP can effectively reduce the emission of total hydrocarbon, carbon monoxide and smoke, while the emission of nitrogen oxides (NOx) is insensitive to the change of DIP, so the trade-off relationship between NOx and smoke disappears. However, excessive DIP will still lead to increased combustion noise, and deteriorated combustion quality caused by too less inducing diesel, etc. The appropriate value is about 1000 bar within the test range. [ABSTRACT FROM AUTHOR]

Small organic molecules absorbing and emitting in the shortwave infrared (SWIR, 1000–2000 nm) region are desirable for biological imaging applications due to low auto‐fluorescence, reduce photon scattering, and good tissue penetration depth of photons which allows for in vivo imaging with high resolution and sensitivity. Si‐substituted xanthene‐based fluorophores with indolizine donors have demonstrated some of the longest wavelengths of absorption and emission from organic dyes. This work seeks to compare an indolizine heterocyclic nitrogen with dimethyl aniline nitrogen donors on otherwise identical Si‐substituted xanthene fluorophores via optical spectroscopy, computational chemistry and electrochemistry. Three donors are compared including an indolizine donor, a ubiquitous dimethyl aniline donor, and a vinyl dimethyl aniline group that keeps the number of π‐bonds consistent with indolizine. Significantly higher quantum yields and molar absorptivity are observed in these studies for a dimethylamine‐based donor relative to a simple indolizine donor absorbing and emitting at similar wavelengths (~1312 nm emission). Substantially longer wavelengths are obtainable by appending aniline‐based groups to the indolizine donor (~1700 nm) indicating longer wavelengths can be accessed with indolizine donors while stronger emitters can be accessed with anilines in place of indolizine. [ABSTRACT FROM AUTHOR]

Sequence‐independent detection of low concentrations of nucleic acids is important for applications in forensics and diagnostics. An emission‐based probe for detecting and quantifying DNA and RNA utilizing a water‐soluble dicationic tetraphenylethene (TPE) derivativewas developed. The recognition is based on the electrostatic and other non‐covalent interactions between the phosphate backbone of nucleic acids and the cationic probe, which cause the restriction of rotation of the aryl units of the probe, ensuing in the enhancement of the fluorescence signal. The binding was validated by different spectroscopic techniques and also by electrophoretic mobility shift assay. The probable mode of binding with the nucleic acids was studied by blind‐docking studies that correlated well with the experimental results. [ABSTRACT FROM AUTHOR]

Agricultural diesel engines can be operated continuously under complex and variable conditions for extended periods. The higher requirements are posed on the Diesel Particulate Filter (DPF) regeneration and reliability. This study aims to enhance the safe and efficient performance of DPF regeneration, emissions, and fuel economy of agricultural diesel engines. An intelligent multi-objective optimization was also proposed to enhance multiple cyclic training. Taking the agricultural engines as the research object, the sample data of the bench test was obtained after experimental design. A prediction model was then constructed in the conditions of DPF regeneration using a Back Propagation neural network (BPNN). According to the Seagull Optimization Algorithm (SOA), the Adaptive Memory Seagull Optimization (AMSO) was proposed to optimize the structure parameters of the BPNN model, in order to meet the requirements of precision. The targets of optimization included T4, T5, O2 concentration, Brake Specific Fuel Consumption (BSFC), NOx, and smoke opacity. In the specific conditions of agricultural diesel engines, multi-objective optimization of injection and intake control parameters was realized under regeneration mode using the Non-dominated Sorting Genetic Algorithm (NSGA)-III. The AMSO-BP prediction model was used to evaluate the fitness of the Pareto optimal solutions, in order to validate the NSGA-III optimal dataset. The optimized MAP values were written into the Engine Control Unit (ECU) after bench tests. Steady-state and World Harmonized Transient Cycle (WHTC) experiments were carried out to verify the multi-objective optimization of the model. The results indicate that the AMSO significantly outperformed the SOA in the optimization of the BPNN prediction model. The AMSO-BPNN prediction model more accurately utilized experimental data to predict the T4, T5, O2 concentration, BSFC, NOx, and smoke opacity, with the R² values of 0.97, 0.99, 0.95, 0.99, 0.98, and 0.95, respectively, on the validation set. Furthermore, the Mean Absolute Percentage Errors (MAPE) on the validation set were reduced by 0.1%, 0.33%, 0.8%, 0.04%, 0.08%, and 4.2%, respectively, compared with the SOA-BP model. The steady-state tests before and after optimization showed that T4 and T5 increased by an average of 3.14%, where the concentration of exhaust oxygen increased by 2.07% and 10.79%, respectively. Simultaneously, the average reductions in the NOx, smoke opacity, and BSFC were 8.68%, 12.07%, and 1.03%, respectively. Efficient and safe DPF regeneration was achieved to significantly reduce the emissions of diesel engines. There was particularly notable optimization under the operation of agricultural diesel engines, which were often working at low speeds and high loads, fully meeting the usage requirements of these engines. The WHTC transient test also showed that the effectiveness of the optimization was achieved in the T4, T5, and O2 concentrations, which increased by 31%, 2.6%, and 0.5%, respectively. Additionally, NOx and soot emissions decreased by 10.4% and 0.8%, and BSFC was reduced by 3.5%. These findings demonstrate that better performance was obtained under the complex and variable conditions of agricultural diesel engines. In conclusion, the safe and efficient DPF regeneration can be expected to reduce the emissions and operational costs for agricultural diesel engines. The specific requirements of agricultural diesel engines can also be fully met to enhance the system reliability in the engineering application. This research can offer practical guidance to optimize the control parameters under the regeneration mode of diesel engines, particularly for more sustainable and efficient agricultural machinery. [ABSTRACT FROM AUTHOR]

In developing countries, electrical power distribution networks are often inadequate, particularly in small health centers. As a result, the electrical energy supplied by the grid is frequently interrupted. The productivity and quality of service delivered by these health centers to the people who live in these areas are severely affected by this issue. This issue can be resolved by incorporating battery storage systems along with renewable energy sources into the distribution system. The direct delivery of energy to customers is greatly aided by these renewable energy supplies. Partially, the grid supports such a system on a limited scale to guarantee the continuity of the energy supply. This study tried to resolve the problem due to these frequent power outages and its economic expenditures. To address the illustrated challenges, we tried to renovate the diesel generator with a solar and battery energy supply. The PVsyst software shows the average global solar radiation in the selected zone is5.84kmh/m2/day$$ 5.84\ \mathrm{kmh}/{\mathrm{m}}^2/\mathrm{day} $$. The annual energy demand for Gedeo health centers in 2023 is 3.32 MWH and the proposed PV‐battery hybrid system has a 10.95 MWH capacity. Moreover, when we utilize a diesel generator the Capital cost (CC), Net present cost (NPC), levelized cost of energy (LCOE), and payback period are 12 452.25$, 13 369.12$, 0.1$, and 10.7 years respectively. The economic assessment result of the proposed system is 4083$, 4727$, 0.059$, and 3.8 years consecutively. In southern Ethiopia, the annual emission from diesel generators alone, excluding the emission from the vehicles is close to 692 tons. Consequently, from the empirical economic assessment the installed solar energy is 90% more beneficial than the existing system. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Shanghai Jiao Tong University (1006-2467) is the property of Journal of Shanghai Jiao Tong University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

South Africa faces the urgency to comprehensively understand and manage its methane (CH4) emissions. The primary aim of this study is to compare CH4 concentrations between Eastern Cape and Mpumalanga regions dominated by cattle farming and coal mining industries, respectively. CH4 concentration trends were analyzed for the period 2019 to 2023 using satellite data. Trend analysis revealed significant increasing trends in CH4 concentrations in both provinces, supported by Mann–Kendall tests that rejected the null hypothesis of no trend (Eastern Cape: p-value = 8.9018e−08 and Mpumalanga: p-value = 2.4650e−10). The Eastern Cape, a leading cattle farming province, exhibited cyclical patterns and increasing CH4 concentrations, while Mpumalanga, a major coal mining province, displayed similar increasing trends with sharper concentration points. The results show seasonal variations in CH4 concentrations in the Eastern Cape and Mpumalanga provinces. High CH4 concentrations are observed in the northwestern region during the December-January–February (DJF) season, while lower concentrations are observed in the March–April-May (MAM) and June-July–August (JJA) seasons in the Eastern Cape province. In the Mpumalanga province, there is a dominance of high CH4 concentrations in southwestern regions and moderately low concentrations in the northeastern regions, observed consistently across all seasons. The study also showed an increasing CH4 concentration trend from 2019 to 2023 for both provinces. The study highlights the urgent need to address CH4 emissions from both cattle farming and coal mining activities to mitigate environmental impacts and promote sustainable development. Utilizing geographic information system (GIS) and remote sensing technologies, policymakers and stakeholders can identify and address the sources of CH4 emissions more effectively, thereby contributing to environmental conservation and sustainable resource management. [ABSTRACT FROM AUTHOR]

The effects of global climate change and related corporate awareness have brought carbon management models to the fore in sectoral strategies aiming to reduce air pollution/carbon emissions. Dry bulk carriers, making up 42.7% of the shipping market, have a significant share in the decarbonisation process. Reducing fuel consumption of ships, playing a significant role in air pollution, is a requirement for environmental sustainability. Thus, a model adopting a holistic approach is required to support decision-making processes in the shipbuilding industry. The study aims to develop a decarbonisation framework by conducting sectoral environmental impact analyses based on entropy management. In this study, the ships' average exergetic efficiency is calculated as 16.91%, and the sectoral improvement potential is 69.32%, so the improvement potential on entropy generation is 79.44%. In the end, it has been concluded that alternative energy solutions are vital for sectoral development in the shipping industry, and recommendations are presented. [ABSTRACT FROM AUTHOR]

Streams are important sources of methane (CH4) to the atmosphere but magnitudes and regulation of stream CH4 fluxes remain uncertain. Stream CH4 can come from groundwater and/or produced in anoxic sediments. A fraction can be microbially oxidized to carbon dioxide (CO2) when passing redox gradients in soil, sediment, or water, while the fraction escaping oxidation is emitted to the atmosphere. The relative importance of the CH4 sources (groundwater inputs vs. sediment production) and the fraction oxidized is typically unknown, yet key for the regulation and magnitude of stream emissions. In this study, we followed the transport of CH4 from below‐stream soils to the stream water surface and to the atmosphere using a combination of CH4 concentration and stable carbon isotope gradient measurements, high resolution stream flux and discharge assessments, and inverse mass‐balance modeling. Sampling was done in multiple locations in the stream network of two independent catchments in Sweden to consider spatial variability. We show that the surface water, sub‐surface, and groundwater CH4 concentration, CH4 oxidation, and emission were highly variable in space. Our results indicate that the variability could be related to stream morphology and soil characteristics. Of the total CH4 input into the streams, roughly half of it was estimated to come from groundwater CH4 in both catchments (39% and 57%; the rest from sediment production), and most of the CH4 was oxidized (97%–99%) before emission to the atmosphere. Our results indicate that CH4 oxidation is a major sink for CH4 in the studied streams. Plain Language Summary: Streams emit a large amount of the greenhouse gas methane to the atmosphere. Sources of this methane can be groundwater and/or production in stream sediments. A part of the methane can be oxidized by microbes into carbon dioxide and the rest can evade to the atmosphere as methane. The relative magnitudes of the sources, oxidation, and emission are usually unknown but important for understanding the regulation of stream methane emissions. In this study in two stream networks of Sweden, inverse mass‐balance modeling was done using multiple measurements and we show that the sources of methane, its oxidation and emission were highly variable in space. About half of the methane in the streams was contributed by groundwater and the rest was estimated to be produced in the sediments. Most of the methane was oxidized in the streams and only a small fraction escaped to the atmosphere. Key Points: Large spatial variability in CH4 concentration, net inputs, oxidation and emission was observedRoughly half of the CH4 inputs in the streams were contributed by groundwater and the rest by sediment productionMost of the total potential stream CH4 input was oxidized before reaching the atmosphere [ABSTRACT FROM AUTHOR]

The fuel injection rate (ROI) is a crucial factor that affects the combustion and emissions of diesel engines. This study focuses on the injection pressure in a common rail system, which is divided into a high-pressure section and a low-pressure section. A control-oriented ROI shaping (ROIs) model is developed based on the switching strategy between high and low injection pressure. Three types of ROI were generated, namely ROIB (conventional ROI), boot-ROI (low followed by high injection pressure), and anti-boot-ROI (high followed by low injection pressure) respectively. The 1-D and 3-D numerical simulations are conducted to analyze the impact of the shaped ROI on combustion and emissions for steady condition and transient condition. In terms of overall results, boot-ROI shows significant advantage among the three types of ROI. For the steady condition, the boot-ROI was able to increase the IMEP (indicated mean effective pressure) (1.57 bar) at high load conditions with almost unchanged NOx emission. For low load conditions with delayed SOI (start of injection), the exhaust temperature is close to that of the ROIB with a reduction of 0.51 g/kW·h in NOx emissions. For transient condition, the boot-ROI also shows its advantage. It was found to improve the BSFC (brake specific fuel consumption) with almost unchanged NOx emission during load-down process. And in load-up process, the BSFC and soot emission also could be improved with slightly increase in NOx emission through advance of SOI when boot-ROI was adopted. The one-dimensional model using boot-ROI reduces fuel consumption by 2 g/kW·h in experiment with WHTC cycles, with slightly higher soot emission and similar NOx emission. [ABSTRACT FROM AUTHOR]

Fuelled engines serve as prime movers in low-, medium-, and heavy-duty applications with high thermal diesel efficiency and good fuel economy compared to their counterpart, spark ignition engines. In recent years, diesel engines have undergone a multitude of developments, however, diesel engines release high levels of NOx, smoke, carbon monoxide [CO], and hydrocarbon [HC] emissions. Due to the exponential growth in fleet population, there is a severe burden caused by petroleum-derived fuels. To tackle both fuel and pollution issues, the research community has developed strategies to use economically viable alternative fuels. The present experimental investigations deal with the use of blends of biodiesel prepared from waste plastic oil [P] and petro-diesel [D], and, to improve its performance, hydrogen [H] is added in small amounts. Further, advanced injection timings have been adopted [17.5° to 25.5° b TDC (before top dead centre)] to study their effect on harmful emissions. Hydrogen energy shares vary from 5 to 15%, maintaining a biodiesel proportion of 20%, and the remaining is petro-diesel. Thus, the adopted blends are DP20 ((diesel fuel (80%) and waste plastic biofuel (20%)), DP20H5 (DP20 (95%) and hydrogen (5%)), DP20H10 (DP20 (90%) and hydrogen (10%)), and DP20H15 (DP20 (85%) and hydrogen (15%)). The experiments were conducted at constant speeds with a rated injection pressure of 220 bar and a rated compression ratio of 18. The increase in the share of hydrogen led to a considerable improvement in the performance. Under full load conditions, with advanced injection timings, the brake-specific fuel consumption had significantly decreased and NOx emissions increased. [ABSTRACT FROM AUTHOR]

A study was conducted to measure aerosol particles emitted from laboratory coats (lab coats) under vibration, comparing them with a suit and a shirt. This study focused on particles ranging from 0.3 μm to >10 μm. Experimental results showed that lab coat vibration increased particles >5 μm while reducing submicron particles. The lab coat (old and used) exhibited greater particle concentration variations under vibration compared to those using the new lab coat or the shirt. Contrastingly, the suit under vibration did not significantly affect particle concentrations. These findings highlight the impact of lab coat vibration on aerosol particle concentrations in the surrounding air, which is important for work environments. [ABSTRACT FROM AUTHOR]

The validation of laser welding of metallic materials is challenging due to its highly dynamic processes and limited accessibility to the weld. The measurement of process emissions and the processing laser beam are one way to record highly dynamic process phenomena. However, these recordings always take place via the surface of the weld. Phenomena on the inside are only implicitly recognizable in the data and require further processing. To increase the validity of the diagnostic process, the multispectral emission data are synchronized with synchrotron data consisting of in situ high-speed images based on phase contrast videography. The welding process is transilluminated by synchrotron radiation and recorded during execution, providing clear contrasts between solid, liquid, and gaseous material phases. Thus, dynamics of the vapor capillary and the formation of defects such as pores can be recorded with high spatial and temporal resolution of <5 μm and >5 kHz. In this paper, laser welding of copper Cu-ETP and CuSn6 is investigated at the Deutsches Elektronen-Synchrotron (DESY). The synchronization is achieved by leveraging a three-stage deep learning approach. A preprocessing Mask-R-CNN, dimensionality reduction PCA/Autoencoders, and a final LSTM/Transformer stage provide end-to-end defect detection capabilities. Integrated gradients allow for the extraction of correlations between defects and emission data. The novel approach of correlating image and sensor data increases the informative value of the sensor data. It aims to characterize welds based on the sensor data not only according to IO/NIO but also to provide a quantitative description of the defects in the weld. [ABSTRACT FROM AUTHOR]

This research tries to establish the emissions diffusion model of high-speed motor vehicles on the Capital Ring Expressway (CRE) around Beijing, China, applying the MOVES and the CALPUFF models. Data required for this study have been collected from different sources. The results show that small buses and large trucks have the highest pollutant emissions on the CRE. The pollutants like CO and HC mainly comes from gasoline vehicles, while NOx, PM10 and PM2.5 comes from diesel vehicles. The average concentrations of the diffusion of CO, NOx, CH4, PM10, and PM2.5 along with the CRE are 6.5 mg/m3, 2.3 mg/m3, 0.27 mg/m3, 0.055 mg/m3 and 0.056 mg/m3 respectively. The results of this study have practical significance and influence on the emission reduction and concentration control strategies under different circumstances, and put forward suggestions on changing transportation modes, strengthening supervision and so on. It has produced a number of recommendations for the policy makers including (1) active promotion of new energy vehicles on expressways, (2) strategic change of the mode of passenger and freight transportation on expressways, (3) strengthen traffic management and supervision of motor vehicles on expressways, and (4) strengthen vegetation protection in rural and ecologically sound areas along the route. [ABSTRACT FROM AUTHOR]

The Sine–Cosine algorithm (SCA) is efficient but faces challenges in exploitative abilities, slow convergence, and exploration–exploitation balance. This study proposes a novel optimization method, the learning-based sine–cosine algorithm (L-SCA), to solve the optimal power flow (OPF) problem. The basic SCA has been modified with a learning phase operator inspired by TLBO. The SCA handles global exploration, while the learner phase of teaching–learning based optimization (TLBO) offers strong local search capabilities, which can be utilized to enhance the solution neighborhood space provided by the SCA technique. The L-SCA and original SCA algorithms address OPF in IEEE 57-bus, Algerian 59-bus, and IEEE 118-bus power systems, considering twelve cases with a focus on cost savings, voltage stability, voltage profile, emissions, and power losses. The comparative study shows that the proposed L-SCA consistently outperforms standard SCA and other reported methods in all cases for varied-scale standard test systems as well as for a practical power system, within reasonable execution times. For instance, L-SCA in the Algerian 59-bus system cut fuel costs by around 13.13% compared to initial case, equating to annual savings of $2.2 million, while in the IEEE-118 bus system, power loss is significantly reduced to 17.881 MW, marking an 86.5% reduction compared to the base case. [ABSTRACT FROM AUTHOR]

In this study, experimental engine tests were conducted to investigate the combustion, performance, and emission characteristics of a diesel engine using a fuel blend composed of diesel, biodiesel, and fusel oil. In the study, which was carried out by using fuels obtained from different wastes together in a diesel engine. Seven different fuels were prepared for experiments by adding waste cooking oil (30% and 50%) and fusel oil (5% and 10%) by volume to commercial diesel fuel. The tests were carried out on the Lombardini LDW 1003 engine, a three-cylinder diesel engine, at four different engine loads (10, 20, 30, and 40 Nm), and a constant speed (2000 rpm). The experimental results revealed that the use of WCO generally led to increased NOx emissions which generally decreased with the fusel oil addition to the fuel mixture. Considering diesel fuel as a reference at maximum load conditions, there was a 12.63% increase in NOx emissions with 50% WCO. A 2.45% decrease in NOx emissions was achieved by adding 10% fusel oil. Furthermore, HC emissions decreased with the addition of both fusel oil and WCO at all load levels. When diesel fuel is taken as a reference at maximum load conditions, a 90% reduction in HC emissions was achieved by adding 50% WCO, and a 50% reduction in HC emissions was achieved by adding 10% fusel oil. Additionally, when diesel fuel is taken as a reference at maximum load condition, it was observed that a 0.05% increase in the maximum cylinder pressure value with the addition of 50% WCO and a 2.09% increase in the maximum cylinder pressure value with the addition of 10% fusel oil. [ABSTRACT FROM AUTHOR]

This study aimed to assess the inclusion of antioxidant diphenylamine (DPA) to a Jatropha biodiesel (B30) blend to affects engine performance and exhaust emissions. In this research, three fuel blends has been utilized: diesel, B30, and 100 ppm of antioxidant diphenylamine is added to the B30 blend referred to as B30 + DPA100. A Response Surface Methodology (RSM) has been employed to analyze experimental data, resulting in the development of a regression equation. Additionally, an Adaptive Neuro-Fuzzy Inference System (ANFIS) has been employed to assess and verify the consistency of the developed model. The results from the experiments revealed that the inclusion of the antioxidant had a notable impact on reducing NOx emissions with only a slight effect on brake thermal efficiency (BTHE). Specifically, B30 + DPA100 showed a 7.48 and 15.53% decrease in average NOx emissions, while the average BTHE experienced a modest 0.78% decrease and a 2.67% increase compared to diesel and B30 biodiesel blend, respectively. The Brake Mean Effective Pressure (BMEP) of B30 + DPA100 has been found to be 3.91% and 1.3% higher than diesel and B30, respectively. The Brake Specific Fuel Consumption (BSFC) was 8.68% lower than B30 but 1.49% higher than diesel. Overall, these findings suggest that B30 + DPA100 can be used in diesel engines without modification, offering reduced NOx emissions. [ABSTRACT FROM AUTHOR]

The present research encompasses the utilization of TiO 2 nano particles with enrichment of H 2 (10 lpm) with Chlorella Emersonii Methyl Ester (CEME) on an agricultural-based CRDI engine. CEME20 (20% chlorella emersonii methyl ester blended with 80% mineral diesel) is employed for the tests. The nanoparticle concentration is limited to 50 ppm which has been considered according to O 2 concentration in biodiesel. Experimentation revealed that, with hydrogen gas and TiO 2 nanoparticles, the BTE and BSFC were improved significantly. At full load conditions, BTE is enlarged by 7.3%. In addition, there is a simultaneous decrease in HC and CO emissions (by about 36.3 and 40.9% respectively) for algal biofuel blends, while NO x emissions increased by 27.3% with respect to mineral diesel. 5.1% and 6.5% increase in combustion characteristics (79.8 bar combustion pressure and 89.2 J/°CA heat release rate)were observed for the CEME/H 2 /TiO 2 blend which could be attributed to effective combustion of hydrogen and catalytic combustion activity provided by TiO 2 nano additives. CEME/H 2 /TiO 2 blend recorded maximum Mass Fraction burnt (MFB) (74.7%) as well as lowered PSD (Particle size Diameter) profile (34.8 nm @ 0.29 E+08 dN/dlogDp (#/cm3)) at full engine load condition indicating the presence of H 2 and nano additives which has influence over the combustion. • Novel idea of Combined influence of H 2 &TiO 2 nano additives in algae biofuel. • Hydrogen gas is inducted at 5 lpm along with 50 ppm TiO 2 nanoparticles. • Surge in BTE (6.95%) & BSFC (6.23%) were resulted with lowered HC and CO emission. • With H 2 and TiO 2 addition, combustion characteristics were significantly enhanced. • Lowered PSD and improved Mass Fraction Burnt (MFB) for CEME/H 2 /TiO 2s. [ABSTRACT FROM AUTHOR]

This paper includes a discussion of the results of tests concerning changes in the thermal and emission parameters of a boiler fuelled with wood biomass under the influence of air gradation in the combustion process. The test results ensure insight into the combustion process of wood biomass with air gradation, which significantly affected the operation of the device, increasing the mass concentration of the emitted nitrogen oxide (NOx) by combustion temperature lowering, especially in the afterburning zone. The authors observed an increase in the emission of particulate matter (PM) and carbon monoxide (CO) related to the change in the combustion process stoichiometry. The tests were carried out with the use of a heating boiler equipped with an automatic pellet burner. Apart from the mass concentration measurement of the pollution emitted, the tests focused on the measurements of temperature and oxygen levels in the flue gas. The objective of the tests was to confirm the applicability of the air gradation techniques in biomass combustion in order to reduce the emission of harmful substances from heating boilers, which is a technique that has recently been used in this group of devices. The test results obtained confirm the necessity for reorganising the technical systems of the currently used pellet burners and implementing further empirical tests. [ABSTRACT FROM AUTHOR]

Enteric CH 4 produced from dairy cows contributes to the emission of greenhouse gases from anthropogenic sources. Recent studies have shown that the selection of lower CH 4 -emitting cows is possible, but doing so would be simpler if performance measures already recorded on farm could be used, instead of measuring gas emissions from individual cows. These performance measures could be used for selection of low emitting cows. The aim of this analysis was to quantify how much of the between-cow variation in CH 4 production can be explained by variation in performance measures. A dataset with 3 experiments and a total of 149 lactating dairy cows with repeated measures was used to estimate the between-cow variation (the variation between cow estimates) for performance and gas measures from GreenFeed (C-Lock, Rapid City, SD). The cow estimates were obtained with a linear mixed model with the diet within period effect as a fixed effect and the cow within experiment as a random effect. The cow estimates for CH 4 production were first regressed on the performance and gas measures individually, and then performance and CO 2 production measures were grouped in 3 subsets for principal component analysis and principal component regression. The variables that explained most of the between-cow variation in CH 4 production were DMI (R2 = 0.44), among the performance measures, and CO 2 production (R2 = 0.61), among gas measures. Grouping the measures increased the R2 to 0.53 when only performance measures were used, and to 0.66 when CO 2 production was added to the significant performance measures. We found the marginal improvement to be insufficient to justify the use of grouped measures rather than an individual measure because the latter simplifies the model and avoids over-fitting. Investigation of other measures that can be explored to increase explanatory power of between-cow variation in CH 4 production is briefly discussed. Finally, the use of residual CH 4 as a measure for CH 4 efficiency could be considered by using either DMI or CO 2 production as the sole predicting variables. [ABSTRACT FROM AUTHOR]

The CO2 emission activity of xylotrophic fungi responding to an increase in temperature in the range of 10–30 °C with pure dikaryotic cultures of Fomes fomentarius s. str., F. inzengae, Fomitopsis betulina, F. pinicola, and Phellinus igniarius was analyzed. Emission activity was assessed by the difference in CO2 concentration in 0.5 L exposure chambers with Petri dishes with mycelium growing on agar at the beginning of exposure and an hour later using a Gasmet DX-4030 FTIR spectrometer (Gasmet Technologies Oy, Finland), error measurements ±50 ppm. Specific (μg CO2/cm2/h) and total (μg CO2/h) emission activity and its relationship with temperature and size (area) of the mycelium were assessed. It is shown that in the range of 10–30 °C, the specific and total CO2 emission activity of the mycelium is closely and positively related to temperature. Specific emission, which is an indicator of the respiratory activity of the mycelium, does not depend on its size; its only driver is temperature, the relationship with which is linear: an increase in temperature by 10 °C causes an increase in the specific emission activity of the mycelium by 1.7 times. The total CO2 emission activity, which is an indicator of the total amount of CO2 emitted, is directly proportional to the specific emission activity and the size of the mycelium. In the range of 10–30 °C, an increase in temperature causes an almost equal increase in both the specific emission activity of the mycelium (Q10 1.7) and its growth (Q10 1.5) and causes an exponential increase in the total emission of CO2. This must be taken into account when predicting CO2 emissions from woody debris under climate change, as it could potentially contribute to accelerating climate change. [ABSTRACT FROM AUTHOR]

A fatty acid alkyl ester can be made from Citrullus Colocynthis oil instead of pure diesel, since it has a higher ratio of triglycerides to monoglycerides. In the current study, the aim of the experimental work was to investigate combustion, emissions, and performance using biodiesel blends derived from Citrullus Colocynthis. A comparison of the qualities of pure Citrullus Colocynthis oil (100% biodiesel), pure diesel (100% diesel), and blended Citrullus Colocynthis and biodiesel (B20, B25, B50, and B75) is presented in the study. The B20 biodiesel blends are the most efficient because of their lower emission concentrations and higher thermal efficiency. Citrullus Colocynthis oil and its blends result in lower in-cylinder pressure and heat release rates. Compared to diesel fuel, a B20 blend performs better and produces less pollution. The test results showed an 18% reduction in HC emissions, a 35% reduction in CO emissions, a 33% reduction in smoke emissions, a 20% reduction in NOx emissions, and a 10% reduction in brake thermal efficiency. [ABSTRACT FROM AUTHOR]

A rapid growth in vehicles and population has resulted in a rapid rise in energy demand. Since fossil fuels are rapidly depleting, researchers are focused on finding alternative fuels for diesel as a result of climate change. The country imports 79% of its oil needs at the moment and plans to reduce that to 70% by 2024. To achieve this, alternative fuel sources that are non-toxic, renewable, and inexpensive are needed. It is emerging that algae-based biodiesel could be a viable alternative to diesel fuel. It has been found that microalgae oil can be used to produce biodiesel. The present study investigates the preparation of a biodiesel fuel blend of 80-20 (80 % diesel and 20 % biodiesel) using nanoparticles of Bi2O3. This research tests the fuels properties in accordance with ASTM standards. It is possible for nanoparticles to enhance fuel properties and overcome certain disadvantages in general by being adding as fuel additives. In this study, Green Microalgae blends and diesel blends containing Bi2O3 nanoadditives were compared for performance and emission characteristics. In experiments, the use of a biodiesel blend with nano-additives resulted in better performance characteristics and lower exhaust emissions. [ABSTRACT FROM AUTHOR]

This study reports enhancing the emission intensity of Dy3+ doped zinc gallate phosphor via Li+ monovalent co-doping. 2–12 mol% Li+ co-doped samples and a 0.05 mol% Dy3+ doped sample were synthesized using a solid-state synthesis technique. X-ray powder diffraction was used to analyze the phase of the synthesized phosphors. By recording the reflectance, the absorption properties were quantified using Ultraviolet-Visible spectroscopy, which displayed absorption peaks corresponding to the Dy3+ activator ions. The Kubelka-Munk function was used to estimate the bandgap and its variation concerning co-dopant concentrations. Energy dispersive electron spectroscopy and field emission scanning electron microscopy have been used to analyze the individual samples' elemental composition and surface morphology. Surface mapping was also conducted using time-of-flight secondary ion mass spectrometry. X-ray photoelectron spectroscopy (XPS) was carried out for the 2 and 10 mol% Li+ co-doped samples to understand the structural properties. XPS confirmed the presence of anti-site defects in the synthesized samples. Phosphorescence spectra were recorded to analyze the effect of the Li+ co-doping on the excitation and emission, which showed a substantial increase in intensity. Apart from Dy3+ characteristic emission, all samples exhibited defect emission using a 299 nm excitation wavelength. The luminescence decay time for both types of emission spectra was recorded and found to be in microseconds. The thermoluminescence technique was used to quantify the trap states created between the valance and conduction bands. The analyzed samples were found to have more than one trap with varying trap densities and activation energies. The color chromaticity coordinates were determined for each sample regarding defect emission and the characteristic emission of the Dy3+ activator ions to assess the color of the emission generated. The information obtained shows promising possibilities that this phosphor material may be a good fit for light-emitting diodes and display technologies based on the emission wavelengths produced. [ABSTRACT FROM AUTHOR]

The primary aim of this study is to alternate between conventional fossil fuels and reduce the emissions of greenhouse gases and sulfur dioxide from diesel engines. In the current study, to mitigate NOx emissions, the exhaust gas recirculation (EGR) technique was implemented utilizing hybrid alternate biodiesel at three varying proportions of 5%, 10%, and 15% at an optimum compression ratio of 20:1. The findings demonstrate that for hybrid alternative biodiesel at a compression ratio of 20:1 and fully loaded, the brake thermal efficiency (BTHE) is 31.8% with 10% EGR. With 15% EGR, the peak pressure for the hybrid biodiesel is lower than it would be without EGR by around 2.28%. When EGR is increased, the ignition delay and NOx emissions are reduced slightly. With only an increase in EGR rates of up to 10%, brake-specific fuel consumption (BSFC) values were reduced efficiently. The hybrid biodiesel with 10% EGR reduces exhaust gas temperature to 341 °C. [ABSTRACT FROM AUTHOR]

The primary aim of this study is to alternate between conventional fossil fuels and reduce the emissions of greenhouse gases and smoke from diesel engines. The current study aimed to improve the performance and emission characteristics of a variable compression ratio (VCR) diesel engine operated with hybrid biodiesel. Experiments were done with the best hybrid biodiesel, which was made by mixing 20% rubber seed oil (RSO) with 80% waste plastic oil (WPO). The tests were done at four compression ratios (CRs): 16:1, 17:1, 18:1, and 20:1. Under a CR of 20:1 and at full load, the engine's brake thermal efficiency went up by 30.5%, its brake-specific fuel consumption went down by 0.347 kg/kWh, and notably diminished emissions of carbon monoxide (0.43% volume), hydrocarbons (79 ppm), and smoke (22%). However, with increasing CRs, NOx emissions rose unfavourably (1092 ppm) compared to diesel (820 ppm). Also, diesel and clean (WPO) were compared to see how the CR values affected combustion, performance, and emissions. Compared to diesel, under maximum load and the CR of 20:1, hybrid biodiesel demonstrated approximately 3.7% higher brake thermal efficiency. The findings suggest potential applications for this hybrid biodiesel in the automobile sector, the power generation industry, and marine applications. Primarni ciljevi ove studije su naizmenično korišćenje konvencionalnih fosilnih goriva, smanjenje emisija gasova sa efektom staklene bašte i dima iz dizel motora, kao i poboljšanje karakteristika performansi i emisija štetnih gasova dizel motora sa promenljivim kompresijom koji radi sa hibridnim biodizelom. Eksperimenti su rađeni sa najboljim hibridnim biodizelom, koji je napravljen namešavanjem 20% kaučukovog ulja sa 80% ulja od otpadne plastike. Ispitivanja su obavljena pri četiri stepena kompresije: 16:1, 17:1, 18:1 i 20:1. Pri stepenu kompresije od 20:1 i pri punom opterećenju, termička efikasnost motora porasla je za 30,5%, specifična potrošnju goriva pala je za 0,347 kg/kWh, a značajno je smanjena emisija ugljen-monoksida (0,43% v/v), ugljovodonike (79 ppm) i dima (22%). Međutim, sa povećanjem stepena kompresije, emisije azotovih oksida su porasle nepovoljno (1092 ppm) u poređenju sa dizelom (820 ppm). Takođe, upoređeni su dizel i čist biodizel of ulja otpadne plastije da bi se videlo kako vrednosti stepena kompresije utiču na sagorevanje, performanse i emisije. U poređenju sa dizelom, pod maksimalnim opterećenjem i stepenom kompresije od 20:1, hibridni biodizel je pokazao približno motora. Nalazi ukazuju na potencijalnu primenu ovog hibridnog biodizela u automobilskom sektoru, industriji proizvodnje energije i pomorskim aplikacijama. [ABSTRACT FROM AUTHOR]

Plant-based diets are increasingly popular nowadays due to their benefits for human health and the environment. Vegan cooking activities also generate pollutants that might affect human health. Compared to outdoor air quality, indoor air quality (IAQ) is still underrated. Moreover, there is a lack of guidelines for pollutants generated in commercial and residential kitchens. The aim of this review was to characterize emission of pollutants arising from cooking of plant-based dishes and necessary instrumentation. Due to scarcity of studies focusing on IAQ for vegan cooking, emission data on the most common indoor air pollutants—fine particulate matter, polycyclic aromatic hydrocarbons, aldehydes, and ketones as well as volatile organic compounds—during cooking of plant-based and vegetarian dishes as well as of edible oil published in the past 10 years were used to estimate IAQ in kitchens. Attempt to define guideline values for air pollution in kitchens has also been made. [ABSTRACT FROM AUTHOR]

There is a recognized need for developing novel energy systems with low pollutions. There has been substantial research undertaken on the role of biomass gasification in developing novel energy systems. The principal objective of this project was to develop a novel tri-generation system to produce electrical power, heating power and freshwater. The system composed of a pine sawdust gasifier, supercritical carbon dioxide Brayton cycles, heat exchanger, desalination unit, combustion chamber, and organic Rankine cycle. Energy, exergy, and environmental analyses were performed on the system by considering equivalence ratio of gasifier, gasifier temperature, compression ratio, and combustion chamber inlet air. The results showed that at higher equivalence ratios, more hydrogen took part in the syngas composition; however, less carbon monoxide and methane participated. Lower equivalence ratios were favorable for more electrical and heating powers produced by the system and less emission effects while it resulted in less freshwater. Increasing compression ratios from 2 to 6 improved electrical power from 895.5 to 1083 kW while declined heating power from 913.9 to 706.9 kW. The system performance was also subjected to signal to noise ratio analysis for optimization purpose. The findings can contribute to a better understanding of driving tri-generation systems of electrical power, heating power, and freshwater based on biomass gasification. [ABSTRACT FROM AUTHOR]

An overview of the main structures of uninterruptible power systems is provided. The impact on internal-system and external-system electromagnetic compatibility of these devices is determined. Contemporary standards and requirements for ensuring electromagnetic compatibility of uninterruptible power systems are analyzed. Features of the structures of uninterrupted power systems such as online, offline and line interactive by the conductive path of propagation of interference are given. The main advantages of eco uninterrupted power supply are summarized. A generalized approach is proposed for the application of radiofrequency interference filters depending on the electromagnetic environment and features of uninterruptible power systems. Refined limitations on the possibilities of adjusting the basic and influence parasitic parameters of the filter links by symmetric and asymmetric propagation of conductive disturbances. The possibility of using remote control of the effectiveness of means of reducing conductive disturbances was assessed. The expediency of localization of control parameters of smart radiofrequency interference filters with the use of artificial intelligence is determined. References 10, figures 6, tables 2. [ABSTRACT FROM AUTHOR]

Sandwich composite is an important part of engineering products capable of replacing metallic composite. It consists of two types of material, namely polypropylene honeycomb core and skin made from jute fiber-reinforced epoxy composite (JFRP), which are joined with glue. This study presented a unique discussion about adhesives that focused on the burning rate and emission performance of SA-A and SD-E. The burning rate performance was assessed with the UL-94 HB test in accordance with the ASTM D 635 standard. Emission value of both adhesives was also examined in line with the ASTM D 2863 standard using a Gasboard-3100P Syngas analyzer. In addition, FTIR and SEM analyses were used to determine the characteristics of the SA-A and SD-E adhesives. The results showed a significant difference in adhesives rates, with SA-A burning 0.5% faster than SD-E in addition to a 0.58% reduced weight loss. Emission test confirmed that both adhesives have similar LOI values of 22.6% and 22.8%, respectively. SA-A adhesives contained LSD, which is dangerous to human health. In conclusion, SD-E adhesives should be used on sandwich composite due to its epoxybased potential as a flame retardant because SA-A adhesives has more potential to trigger firing due to the fuel content. [ABSTRACT FROM AUTHOR]

In the current era, it has become essential to move toward highly efficient and low-emission engines as the norms for automobile emissions are very stringent and closely monitored; moreover, it also tends to be more strictly regulated in the future. The aim of this experimental work is to optimize engine efficiency as well as reduce emissions to the maximum using oxygen-enriched air. An onboard oxygen generator can provide oxygen-enriched air instead of an oxygen cylinder, as the latter one is prone to cause safety issues. In this experimental study, oxygen is obtained through generator and is sent to the engine's intake manifold, where the atmospheric air merges with it. The parameters of combustion, performance, and emission of this oxygen-enriched air were examined in a constant-speed compression ignition engine. The result shows that the engine's brake thermal efficiency increased by 5.4% at 25% of brake power as compared to the thermal efficiency attained in atmospheric air combustion. Similarly, brake-specific fuel consumption also decreased in the oxygen-enriched combustion process. The emissions of hydrocarbon and carbon monoxide also decreased to 18.8% and 33.3%, respectively, for 25% of the brake power; notably, the smoke emissions reduced drastically to 32% at the same brake power. The oxides of nitrogen emission, however, increased with the air's oxygen content. [ABSTRACT FROM AUTHOR]

The article presents the problem of particulate matter and heavy metal emissions from the tribological systems (road abrasion, brake and tyre wear) road of cars equipped with internal combustion engines (ICEs), battery electric vehicles (BEVs), hybrids and plug-in vehicles (PHEVs). The results of mathematical modelling carried out for obtaining of the emissions of particulate matter and heavy metals, such as As, Cd, Cr, Cu, Ni, Pb, Se and Zn, resulting from road abrasion, brakes and tyre wear, are presented. Emissions are shown depending on the average speed and type of traffic (traffic in the city (urban), outside the city (rural) and on the highway) and the type of vehicle. [ABSTRACT FROM AUTHOR]

The article focuses on emission analysis of non-CO2 pollutions from aircraft engines on different flight levels: FL240, FL300 and FL350. The calculation was made based on the A320 flight from Berlin to Lisbon at flight level 350, which was the reference flight level in the analysis. Four sustainable aviation fuels have been taken into consideration: biofuel from jatropha and biofuel from camelina, which are used in different percentages of fuel: 20% of CSPK and JSPK and 40% of CSPK and JSPK. The results showed that the lowest emission of carbon monoxide is on the lowest tested flight level for flight on biofuel, and the lowest emission of nitrogen oxides is for Jet A-1 on the lowest tested flight level. Emission of every toxic gas compound has been compared to conventional jet fuel on flight level 350 to show the differences between flight levels. [ABSTRACT FROM AUTHOR]

The tofu industry is one of the industries that has grown and developed a lot in Indonesia to meet the community's food needs. In the tofu production cycle, many activities have the potential to produce emissions that are harmful to the environment, one of which is greenhouse gases (GHGs). There are various activities carried out by the tofu industry to produce products that are ready for sale, starting from the procurement of raw materials, the production and distribution of tofu to the market. The longer the tofu production chain, the greater the potential to produce GHG emissions. To find out the amount of GHG emissions produced, it is necessary to take a tofu product life cycle (LCA) assessment. Therefore, this study aims to calculate the GHG emissions produced in the tofu production cycle in the X’s tofu industry. The results show that X’s tofu industry produces GHG emissions of 3,373.53 KgCO2eq per 300 kg soybean which originate from the use of electricity, gasoline, firewood, and liquid waste. Every activity carried out also contributes to the emergence of GHG emissions. The highest GHG comes from the use of firewood of 3,198.81 KgCO2eq, meanwhile, the stage that generates the most GHG is during the cooking stage. Alternative improvements that can be made to reduce emissions are minimizing the use of transportation equipment, minimizing water usage (water reduction), water reuse, converting the use of firewood to LPG, and utilizing liquid waste into biogas for the cooking process.

The analysis of environmental impacts throughout the entire process of coal-fired power plants is imperative to implement effective measures for controlling and reducing pollutant emissions. However, there is still limited research focusing on the cradle-to-gate stage in the life cycle of coal-fired power plants and their environmental impact. This study employs a life cycle assessment (LCA) methodology to assess the environmental impacts of coal-fired power plants in South Sumatra. The primary environmental impact categories of primary emissions include CO2, SO2, NOx, and CH4. The most significant environmental impacts arise from CO2 emissions, notably 98.46% from land clearing and preparation and 86.74% from overburden removal and coal extraction. These stages primarily contribute to global warming throughout the cradle-to-gate process. Sulfur dioxide emissions from land clearing activities are the main contributor to acid rain, followed by overburden removal and coal extraction (96.51%) and coal stockpiling (1.48%), which also play a role. The release of NOx from land clearing and preparation, overburden removal, and coal stockpiling contributes to the potential for eutrophication. Land clearing and preparation have a significant impact on global warming during the coal mining and distribution stages. Practical measures such as enhancing emission reduction facilities and increasing pollutant emission standards for each process are necessary to promote environmentally friendly coal-fired power plants.

ObjectiveTo improve the combustion, performance and emissions of high-power marine engines, diesel fuel micro-injection with methanol ignition is adopted to study the in-cylinder combustion and emission characteristics. MethodsA three-dimensional simulation model of a diesel micro-injection pilot-ignition methanol engine is established on the basis of an ACD320 high-power marine medium-speed diesel engine in order to study the effects of injector parameters (nozzle number and methanol spray angle γ) on the combustion performance and emission characteristics of a marine large-bore methanol engine.ResultsWith the increase in the number of nozzle, the in-cylinder methanol atomization improves and the in-cylinder work mass mixing becomes more adequate, leading to the advancement of CA50 and the shortening of the combustion duration. While this yields higher indicated thermal efficiency（ITE） and a better equivalent indicated specific fuel consumption (EISFC), as well as contributing to the reduction of soot emissions, it also causes the elevation of NOx emissions. Moreover, as the methanol spray angle increases, the ITE increases, obtaining better fuel economy and lower soot emissions. With the optimal methanol spray angle (γ = 60°), the methanol spray is located in front of the diesel spray injection point, the flame propagation speed in the cylinder is faster, the indicated thermal efficiency is at its maximum and the fuel combustion is fuller, thereby obtaining the lowest soot emissions and most optimal EISFC.ConclusionThe results of this analysis can provide a theoretical basis for engine injector parameters.

In order to obtain the influencing rule of secondary combustion on emissions and combustion oscillation characteristics of gas turbine axial staged combustor in non-premixed combustion mode and explore a load increasing mode with stable low emission, an axial staged combustor for F-class gas turbines is selected for experimental study. The results show that CO consumption is restrained and CO emission increases sharply when secondary fuel is added at a lower combustor outlet temperature. The addition of secondary fuel and the increase of secondary equivalence ratio lead to the reduction of NOx emission, but the increase of load can weaken the ability of secondary fuel to reduce NOx emission. The addition of secondary fuel and the increase of secondary equivalence ratio restrain the combustion oscillation in the low frequency band (75—90 Hz). When the secondary equivalence ratio is higher than a certain threshold (0.19), the addition of secondary fuel can restrain higher frequency(175—210 Hz) combustion oscillation. In addition, by comprehensively considering the influence of secondary combustion on emissions and combustion oscillation, the operating range and load increasing mode of low emissions and stable combustion of axial staged combustor in the higher load range (20%—50% load) are obtained, which provides a reference for stable low emission operation of the unit during load increasing.