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External pressure is one of the key parameters to understand photoemission nanomaterials since the external pressure changes their photoproperties without introducing any chemical treatment. Here, we computationally elucidated the effects of the external pressure on structures, orbitals, photoproperties, and vibrational dynamics of a silicon vacancy (SiV) diamond nanoslab. We studied its attributes not only on the ground state at 0 K but also on the excited state around room temperature (RT) using an ab initio molecular dynamics simulation. We directly and mechanically pressed the SiV diamond nanoslab fluctuating around RT to mimic an actual external pressure usually generated in an anvil cell at RT. We found that the compression induces the shrunk SiV defect structures, the rearranged defect orbital energies, the switch of the optical transition from the SiV–SiV excitation to the nanoslab–SiV excitation, the hybridization of the SiV with nanoslab carbon (C) orbitals, and the blue shift and the smaller intensity of the spectra of the Si atom oscillation and the inner C–C bond vibration. The energies of absorption, emission, and zero-phonon line do not change monotonically but have the maxima below a 7%-compression. Especially, the absorption energy differs more between 0 K and RT as the compression increases, while the largest deviation between 0 K and RT in the emission energy appears below the 7%-compression. It is remarkable that all of these changes are caused only by the mechanical compression and that the compression differently pronounces the temperature effect. The obtained insights will provide a way to effectively control a split-vacancy center to be a promising single-photon source for nanoscale optical measurements of temperature and pressure in a compressed nanoscale material.

In the next few years, numerous satellites with high-resolution instruments dedicated to the imaging of atmospheric gaseous compounds will be launched, to finely monitor emissions of greenhouse gases and pollutants. Processing the resulting images of plumes from cities and industrial plants to infer the emissions of these sources can be challenging. In particular traditional atmospheric inversion techniques, relying on objective comparisons to simulations with atmospheric chemistry transport models, may poorly fit the observed plume due to modelling errors rather than due to uncertainties in the emissions. The present article discusses how these images can be adequately compared to simulated concentrations to limit the weight of modelling errors due to the meteorology used to analyse the images. For such comparisons, the usual pixel-wise ℒ2 norm may not be suitable, since it does not linearly penalise a displacement between two identical plumes. By definition, such a metric considers a displacement as an accumulation of significant local amplitude discrepancies. This is the so-called double penalty issue. To avoid this issue, we propose three solutions: (i) compensate for position error, due to a displacement, before the local comparison; (ii) use non-local metrics of density distribution comparison; and (iii) use a combination of the first two solutions. All the metrics are evaluated using first a catalogue of analytical plumes and then more realistic plumes simulated with a mesoscale Eulerian atmospheric transport model, with an emphasis on the sensitivity of the metrics to position error and the concentration values within the plumes. As expected, the metrics with the upstream correction are found to be less sensitive to position error in both analytical and realistic conditions. Furthermore, in realistic cases, we evaluate the weight of changes in the norm and the direction of the four-dimensional wind fields in our metric values. This comparison highlights the link between differences in the synoptic-scale winds direction and position error. Hence the contribution of the latter to our new metrics is reduced, thus limiting misinterpretation. Furthermore, the new metrics also avoid the double penalty issue.

Biodiesel is being considered a possible alternative fuel due to its similarity with diesel and environmental benefits. This current work involves a numerical investigation of CI engine characteristics operating on D100 (diesel) and Dunaliella tertiolecta (DMB20), Scenedesmus obliquus (SOMB20), Scenedesmus dimorphu (SDMB20), and Chlorella protothecoides (CMB20) microalgae biodiesel blend. A diesel engine of 3.7 kW was used with variable compression ratios (CRs) (15.5, 16.5, 17.5, and 18.5) and constant speed (1500 rpm). Comparative analysis was performed for engine characteristics, including emission, combustion, and performance. Cylinder pressure, heat release rate, brake thermal efficiency, specific fuel consumption, particulate matter, oxide of nitrogen, carbon dioxide, etc., were evaluated using the blended fuel. The results show that the maximum cylinder pressure falls, SFC increases, and EGT and BTE were reduced for all blends at full load. In terms of emission characteristics, PM and smoke were lowered when compared to diesel, but a slight increment in NOx and CO2 was observed. Among all the blends, SOMB20 shows the most decrement in PM and smoke emissions by 14.16% and 11.6%, respectively, at CR 16.5. CMB20 shows a maximum increment in SFC by 3.22% at CR 17.5. A minimum reduction in CP and HRR was shown by DMB20 irrespective of CRs.

The cold filter plugging point (CFPP) value of biodiesel fuel blends need to be improved because of it has been reported that utilizing high concentrations of biodiesel blends in cold climates can cause major issues. Therefore, the main objective of the study is to improve CFPP value of biodiesel blends using ethyl proxitol additive. It is also to examine combustion and emission of the blends behavior. Biodiesel blends were prepared as; 5% ethyl proxitol-10% biodiesel-85% ultra-low sulfur diesel (ULSD) named as E5B10 and 5% ethyl proxitol-20% biodiesel-75% ULSD named as E5B20 fuel. These fuel blends were compared with ULSD fuel in a compression ignition engine at a constant engine speed of 1500 rev/min and four different loads (idle, 1, 2, and 3 bar BMEP) of eddy current dynamometer. The addition of ethyl proxitol led to a decrease in in-cylinder pressure and temperature due to an about 1˚ later SOC and 2˚ earlier EOC compared to ULSD. The pressure rise rate was slightly higher compared to ULSD at both low and high loads, with a difference of about 1 bar per degree. As a result, these blends with improved CFPP value can be used in cold climates.

Understanding and actively controlling the spatiotemporal dynamics of nonequilibrium electron clouds is fundamental for the design of light and electron sources, high power electronic devices, and plasma-based applications. However, electron clouds evolve in a complex collective fashion on the nanometer and femtosecond scales, producing electromagnetic screening that renders them inaccessible to existing optical probes. Here, we solve the long-standing challenge of characterizing the evolution of electron clouds generated upon irradiation of metallic structures using an ultrafast transmission electron microscope to record the charged plasma dynamics. Our approach to charge dynamics electron microscopy (CDEM) is based on the simultaneous detection of electron-beam acceleration and broadening with nanometer/femtosecond resolution. By combining experimental results with comprehensive microscopic theory, we provide a deep understanding of this highly out-of-equilibrium regime, including previously inaccessible intricate microscopic mechanisms of electron emission, screening by the metal, and collective cloud dynamics. Beyond the present specific demonstration, the here-introduced CDEM technique grants us access to a wide range of nonequilibrium electrodynamic phenomena involving the ultrafast evolution of bound and free charges on the nanoscale., ACS Nano, 17 (4), ISSN:1936-0851, ISSN:1936-086X

External accretion events such as a galaxy merger or the accretion of gas from the immediate environment of a galaxy, can create a large misalignment between the gas and the stellar kinematics. Numerical simulations have suggested that misaligned structures may promote the inflow of gas to the nucleus of the galaxy and the accretion of gas by the central supermassive black hole. We show for the first time that galaxies with a strong misalignment between the ionised gas and stellar kinematic angles have a higher observed fraction of active black holes than galaxies with aligned rotation of gas and stars. The increase in black hole activity suggests that the process of formation and/or presence of misaligned structures is connected with the fuelling of active supermassive black holes., Comment: To be published in Nature Astronomy on 19 January 2023. Authors' version

Full list of authors: Levan, A. J.; Lamb, G. P.; Schneider, B.; Hjorth, J.; Zafar, T.; de Ugarte Postigo, A.; Sargent, B.; Mullally, S. E.; Izzo, L.; D'Avanzo, P.; Burns, E.; Fernandez, J. F. Aguei; Barclay, T.; Bernardini, M. G.; Bhirombhakdi, K.; Bremer, M.; Brivio, R.; Campana, S.; Chrimes, A. A.; D'Elia, V.; Valle, M. Della; De Pasquale, M.; Ferro, M.; Fong, W.; Fruchter, A. S.; Fynbo, J. P. U.; Gaspari, N.; Gompertz, B. P.; Hartmann, D. H.; Hedges, C. L.; Heintz, K. E.; Hotokezaka, K.; Jakobsson, P.; Kann, D. A.; Kennea, J. A.; Laskar, T.; Le Floc'h, E.; Malesani, D. B.; Melandri, A.; Metzger, B. D.; Oates, S. R.; Pian, E.; Piranomonte, S.; Pugliese, G.; Racusin, J. L.; Rastinejad, J. C.; Ravasio, M. E.; Rossi, A.; Saccardi, A.; Salvaterra, R.; Sbarufatti, B.; Starling, R. L. C.; Tanvir, N. R.; Thoene, C. C.; van der Horst, A. J.; Vergani, S. D.; Watson, D.; Wiersema, K.; Wijers, R. A. M. J.; Xu, Dong.--This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited., We present James Webb Space Telescope (JWST) and Hubble Space Telescope (HST) observations of the afterglow of GRB 221009A, the brightest gamma-ray burst (GRB) ever observed. This includes the first mid-IR spectra of any GRB, obtained with JWST/Near Infrared Spectrograph (0.6–5.5 micron) and Mid-Infrared Instrument (5–12 micron), 12 days after the burst. Assuming that the intrinsic spectral slope is a single power law, with Fν ∝ ν−β, we obtain β ≈ 0.35, modified by substantial dust extinction with AV = 4.9. This suggests extinction above the notional Galactic value, possibly due to patchy extinction within the Milky Way or dust in the GRB host galaxy. It further implies that the X-ray and optical/IR regimes are not on the same segment of the synchrotron spectrum of the afterglow. If the cooling break lies between the X-ray and optical/IR, then the temporal decay rates would only match a post-jet-break model, with electron index p < 2, and with the jet expanding into a uniform ISM medium. The shape of the JWST spectrum is near-identical in the optical/near-IR to X-SHOOTER spectroscopy obtained at 0.5 days and to later time observations with HST. The lack of spectral evolution suggests that any accompanying supernova (SN) is either substantially fainter or bluer than SN 1998bw, the proto-type GRB-SN. Our HST observations also reveal a disk-like host galaxy, viewed close to edge-on, that further complicates the isolation of any SN component. The host galaxy appears rather typical among long-GRB hosts and suggests that the extreme properties of GRB 221009A are not directly tied to its galaxy-scale environment. © 2023. The Author(s). Published by the American Astronomical Society., A.J.L., D.B.M., and N.R.T. are supported by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement No. 725246). G.P.L. is supported by a Royal Society Dorothy Hodgkin Fellowship (grant Nos. DHF-R1-221175 and DHF-ERE-221005). J.H. and L.I. were supported by a VILLUM FONDEN Investigator grant to JH (project No. 16599). B.D.M. acknowledges support from the National Science Foundation (grant No. AST-2002577). J.P.U.F. acknowledges support from the Carlsberg Foundation. The Cosmic Dawn Center (DAWN) is funded by the Danish National Research Foundation under grant No. 140. D.A.K. acknowledges the support by the State of Hessen within the Research Cluster ELEMENTS (Project ID 500/10.006). R.B., M.G.B., S.C., P.D.A., M.F., A.M., and S.P. acknowledge funding from the Italian Space Agency, contract ASI/INAF No. I/004/11/4. P.D.A. acknowledges support from PRIN-MIUR 2017 (grant 20179ZF5KS). J.F.A.F. acknowledges support from the Spanish Ministerio de Ciencia, Innovación y Universidades through the grant PRE2018-086507., With funding from the Spanish government through the "Severo Ochoa Centre of Excellence" accreditation (CEX2021-001131-S).

Globally, with the rapid growth of the population, the use of cars is also increasing. Although there is an increase in the use of electric vehicles, the vast majority of the vehicles used are internal combustion engine vehicles. Fossil fuel vehicles have disadvantages such as damaging the environment due to their high emission values, using non-renewable energy sources as fuel, high maintenance costs, and complex vehicle structures. Electric vehicles have many advantages such as being sensitive to the environment with a near-zero emission value, simple structures, low maintenance costs, and the use of renewable energy sources as fuel. Today, the reserve ratios of fossil fuels are rapidly depleting. Consumers tend to buy electric vehicles because of the environmental damage caused by fossil fuel vehicles due to the high emissions they emit, and because of the danger of depletion of non-renewable energy sources. The purchase of electric vehicles from the factory is difficult due to the few product varieties and the high prices in the market. It is possible for consumers to have electric vehicles with the features, colors, and models they want at much more affordable prices, by converting internal combustion engine vehicles to electric vehicles. Each country has its own regulations for the conversion process. Transformation operations in our country are carried out in accordance with the Regulations of the Ministry of Science, Industry, and Technology. There are ready-made conversion kits of different brands on the market that contain the components necessary for the conversion of internal combustion engine vehicles to electric vehicles. In this study, the advantages and disadvantages of internal combustion engine vehicles and electric vehicles, why conversion is necessary, and how conversion should be carried out will be discussed. Thanks to the conversion to an internal combustion engine, there will be a decrease in the emission of harmful gases to the environment, an economic contribution will be made to the country, and consumers will be able to have the vehicle they want at affordable prices.

RCCI engine is among the most promising combustion technology for the upcoming generation ofheavy-duty motors. In RCCI mode combustion, different combinations of low reactivity fuels (LRF) and highreactivity fuels (HRF) such as PRF-Diesel, can be used to achieve a chemical reaction or reactivity stratificationin the engine combustion chamber. The high reactivity fuel (HRF) which is diesel will be injected in the directfuel injection and the low reactivity fuel (LRF) which is Primary Reference Fuel (PRF) will be injected in portfuel injection. Combustion in the engine combustion chamber will convert the chemical energy of fuels to heatthat can be used directly or further converted to mechanical energy. Internal combustion engine outputsmechanical power by extracting energy in fuels via combustion reaction in the cylinders. Fuels are burned in thecombustion chambers to generate high temperature and high-pressure gas which delivers power to the piston.RCCI had a low performance at high engine speed due to its high tendency on knocking and high pressure riserate. Therefore, this study investigates the effect of the fuel stratification on the RCCI combustion and it’sextended to the interaction of high and low reactive fuels, PRF and diesel in the RCCI combustion system.Modified engine was tested for engine performance. The change in BSFC, Power and Torque are observed at allloads and speeds with different PRF percentages. For emissions, this RCCI engine was said to producesextremely low in nitrogen oxide. On a regular diesel engine, these kinds of pollutants cause problems. The coolburning, on the other hand, does not emit nitrogen oxide when using an RCCI engine. Aside from that, becausethe RCCI engine uses less diesel fuel, the diesel fuel has more time to mix in the cylinder.

This study presents the analysis of multi-distributed generation systems for 20 off-grid homes in Ogun State based on the techno-environmental analysis planning (TEAP) approach. The technical aspect includes the load, DG capacities, energy generation/year, and the unmet energy demand (UED. The paper considers and compares different energy configurations such as the PV-based DG, the hybrid DGs: PV/biogas, PV/biogas/natural gas, PV/biogas/diesel, PV/diesel, and the diesel-based DGs. The environmental aspect examines the emissions produced by the DGs compared to a diesel-based DG system. The paper also examines the effect of temperature on the performance of the PV system. The simulation is based on a total daily demand of 99.04 kWh/d, and the solar, ambient temperature and the biomass data in Hybrid Optimization of Multiple Energy Resources (HOMER) environment. The size of the PV-based DG obtained is 36.9 kW, which generates 54,565 kWh/yr without temperature effect. Result shows that this value reduced to 48,268 kWh/yr with temperature effect and the value of UED is 7.84 %. The biogas, natural gas and diesel generators have the same size of 13.2 kW. The hybrid DGs achieve a UED of 0% implying 100 % system availability. Results further demonstrate that the mentioned hybrid DGs have CO2 emissions that range between 2.21 and 15, 448 kg/yr, compared to a value of 40, 273 kg/yr obtained when the homes are entirely run on a diesel-based DG. The study can help to understand energy systems analysis.

Given the importance of the environment around the world and its accelerating destruction brought on by the increase in emissions resulting from the growing use of various forms of transportation, this paper shall aim to eliminate this research gap via a thorough investigation of the literature. These goals include the effect of greenhouse gases emitted by the transportation industry on the environment, the impact of pollutants on transportation mode choice, a study of the obstacles to reducing pollution in transportation, and the presentation of solutions and suggestions. In the research, papers related to this topic in various transportation industries, including road, rail, marine, air, and multimodal transportation, and the variables affecting the control of greenhouse gas emissions in any mode of transportation were collected. Afterward, fundamental analysis was carried out, conclusions drawn, and the presentation of suggestions and solutions in this area addressed. Reducing greenhouse gases in transportation is a challenge that requires examining numerous influential variables and factors. The studies presented in this research are expected to be useful, especially for the energy activists, researchers, and policymakers who would like to conduct long-term studies of pollutants in the transportation industry and the variables influencing the control of greenhouse gas emissions.

Ammonia mitigation systems in dairy houses with a slurry pit below, often close off the pit to limit air circulation between the pit and the house. Currently, the effect of limiting air recirculation on emission is unknown. Experiments were carried out to understand the effect of closing off the pit on NH3 emissions. This study aimed to (1) develop a method to quantify continuous pit air flow rate, (2) provide information about gas concentrations inside a slurry pit and (3) determine the effect of closing off the floor on air exchange rate between pit and house. Mass balances for CO2 and CH4 were set up to quantify air exchange rate between pit and house based on natural slurry production. The applicability of this approach was tested for both a conventional slatted floor as well as for an NH3 mitigating closed floor. The ventilation rate estimates of the mass balance were compared to the ventilation rate as determined with a rate-of-decay (ROD) experiment. Quantification of pit ventilation rate based on the CO2 and CH4 mass balances is most appropriate to discover relative differences. Pit ventilation rate turned out to be temperature dependent and therefore showes a clear day–night pattern with ventilation rates during the night. The ROD method provided a more accurate quantification of the ventilation rate and showed replacement rates during daytime of 4.3–7.3 h−1.

Dust storms originate from drylands and bring hazards and dramatic socio-economic impacts. This paper reviews the impacts of this phenomenon on human health, pollution of air, and socio-economic situations by focusing on susceptible areas to dust and sandstorms in Iran. It provides a short review of the dust and sandstorm phenomenon and the process of dust emissions. In addition, it reviews possible sources of dust and sandstorms inside Iran's borders and concludes that it originates from dried bed lakes which are located inside Iran. To consider the countermeasures of the hazardous effects of the dust storms, accurate prediction methods are required to be developed with plausible physical models describing the sand transport phenomenon with the association of mesoscale atmospheric predictions models. Accordingly, case studies employing atmospheric numerical simulation models were discussed. This study highlights the importance of the numerical predictions of dust storms that frequently occur in Iran.

We present a Bayesian inference on the neutral hydrogen fraction of the intergalactic medium (IGM), $\overline{x}_{\small HI}$, at z ∼ 6–8 using the properties of Lyman break galaxies (LBGs) during the epoch of reionization. We use large samples of LBG candidates at 5.5 ≤ z ≤ 8.2 with spectroscopy from Keck/DEIMOS and Keck/MOSFIRE. For each galaxy, we incorporate either the Lyman-α (Lyα) equivalent width (EW) for detections or the EW limit spectrum for non-detections to parametrize the EW distribution at various ultraviolet brightnesses for a given redshift. Using our reference sample of galaxy candidates from the ionized universe at z ∼ 6.0, we are able to infer $\overline{x}_{\small HI}$ at two redshifts: z ∼ 6.7 and z ∼ 7.6. This work includes intrinsically faint, gravitationally lensed galaxies at z ∼ 6.0 in order to constrain the intrinsic faint-end Lyα EW distribution and provide a comparable population of galaxies to counterparts in our sample that are at higher redshift. The inclusion of faint galaxy candidates, in addition to a more sophisticated modelling framework, allows us to better isolate effects of the interstellar medium and circumgalactic medium on the observed Lyα distribution from those of the IGM. We infer an upper limit of $\overline{x}_{\small HI}$ ≤ 0.25 (0.44) at z = 6.7 ± 0.2 and a neutral fraction of $\overline{x}_{\small HI}$ = $0.83^{+0.08}_{-0.11}$ (0.83$^{+0.11}_{-0.21}$) at z = 7.6 ± 0.6, both within 68 per cent (95 per cent) uncertainty, results that favour a moderately late and fairly rapid reionization.

This study aims to characterize the waste of weaned piglets and estimate the emissions of N2O in kg of CO2 eq/kg of weight gain in the first week of housing. Primary data were obtained in the first week after weaning of piglets to identify how much waste from this animal category may affect the environment. The life cycle assessment was applied to verify the amount of manure and the emission of nitrous oxide (N2O) considering the weight gain (WG) of piglets in the first post-weaning week. Eight waste collections were carried out in two lots representing an average of 8,099 animals with initial and final weight of 5.01 and 5.84 kg, respectively. The production of residues was 0.128 kg of dry matter (DM) for each kilogram of WG produced. This waste production has an emission capacity of approximately 4x10-4 kg N2O/kg WG in the first post-weaning week. Considering that N2O has a global warming potential almost 300 times higher in retaining heat than CO2, each 1 kg of piglet produced can emit about 0.129 kg of CO2 equivalent from the N2O produced. According to the number of piglets evaluated in this study, the total emission can reach 1.85 tons of CO2 equivalent in the first post-weaning week alone. This study aims to characterize the waste of weaned piglets and estimate the emissions of N2O in kg of CO2 eq/kg of weight gain in the first week of housing. Primary data were obtained in the first week after weaning of piglets to identify how much waste from this animal category may affect the environment. The life cycle assessment was applied to verify the amount of manure and the emission of nitrous oxide (N2O) considering the weight gain (WG) of piglets in the first post-weaning week. Eight waste collections were carried out in two lots representing an average of 8,099 animals with initial and final weight of 5.01 and 5.84 kg, respectively. The production of residues was 0.128 kg of dry matter (DM) for each kilogram of WG produced. This waste production has an emission capacity of approximately 4x10-4 kg N2O/kg WG in the first post-weaning week. Considering that N2O has a global warming potential almost 300 times higher in retaining heat than CO2, each 1 kg of piglet produced can emit about 0.129 kg of CO2 equivalent from the N2O produced. According to the number of piglets evaluated in this study, the total emission can reach 1.85 tons of CO2 equivalent in the first post-weaning week alone.

The recurrent nova RS Oph underwent a new outburst on August 8, 2021, reaching a visible brightness of V = 4.8 mag. Observations of the 2021 outburst made with the high resolution UVES spectrograph at the Kueyen-UT2 telescope of ESO-VLT in Paranal enabled detection of the possible presence of 7Be freshly made in the thermonuclear runaway reactions. The 7Be yields can be estimated in N(Be)/N(H) = 5.7 x 10^(-6), which are close to the lowest yields measured in classical novae so far. 7Be is short-lived and decays only into 7Li. By means of a spectrum taken during the nebular phase we estimated an ejected mass of about 1.1 x 10^(-5) Msun, providing an amount of about 4.4x 10^(-10) Msun of 7Li created in the 2021 event. Recurrent novae of the kind of RS Oph may synthesize slightly lower amount of 7Li per event as classical novae, but occur 10^3 times more frequently. The recurrent novae fraction is in the range of 10-30% and they could have contributed to the making of 7Li we observe today. The detection of 7Be in RS Oph provides further support to the recent suggestion that novae are the most effective source of 7Li in the Galaxy., Accepted 2022 September 17. Received 2022 September 16; in original form 2022 April 20. 12 pages, 13 figures

Purpose The purpose of this study is to have semiempirical correlations for carbon monoxide (CO), unburned hydrocarbon (UHC) and nitrogen oxide (NOx) emissions that are collected and calibrated by using experimental data of a tubular-type combustor. Design/methodology/approach Combustor uses a coflow radial-type air-blast atomizer and is especially designed for the empirical correlation issues. Air mass flow rate, air inlet temperature and air-to-fuel ratio parameters have been changed and different inlet conditions have been created for combustor tests. Six different inlet temperatures from 475 to 350 K have been set for each air mass flow rate. Air mass flow rate values from 0.035 to 0.050 kg/s have been used to create varied combustor aerodynamic loadings. Findings Increasing combustor inlet temperature decreases the CO and UHC emissions. However, it has an adverse effect in NOx emissions. Moreover, CO and UHC emissions have an increasing trend by the mass flow rate rise that results an extra aerodynamic loading. Research limitations/implications It is difficult to obtain real operating parameters for the combustor. Therefore, as a different approach in respect of the literature, rig test parameters have been used for thermodynamic calculations. Additionally, emission calculations of the combustor design point have been performed based on a conditioned test environment. Moreover, combustor outlet temperature and emission values have been scanned and mean values used for the analysis. Practical implications To perform preliminary calculations for these pollutants, designers need experimentally calibrated correlations for the similar combustors. Social implications If the application area of the designed engine is a civil aircraft, emissions are one of the most important issues because of the strict regulations of International Civil Aviation Organization. Therefore, aviation companies are continuously working on reducing of emissions. Originality/value A comprehensive study for the preliminary emission calculation of newly designed gas turbine combustors was performed to investigate semiempirical correlations in the atmospheric test rig.

In this numerical study, the effects of the premixed ratio, intake manifold pressure and intake air temperature on a four-cylinder, four-stroke, direct injection, low-compression-ratio gasoline engine, operated in reactivity-controlled compression ignition (RCCI) combustion mode at a constant engine speed of 1000 rpm, were investigated using Converge CFD software. The results of numerical analyses showed that the maximum in-cylinder pressure and heat release rate (HRR) increased and the combustion phase advanced depending on the rise in both intake manifold pressure and intake air temperature. The CA50 shifted by 18.5 °CA with an increment in the intake air temperature from 60 °C to 100 °C. It was observed that the combustion duration dropped from 44 °CA to 38 °CA upon boosting the intake manifold pressure from 103 kPa to 140 kPa. Moreover, a delay in the combustion phase occurred at a constant intake air temperature with an increasing premixed ratio. The maximum value of in-cylinder pressure was recorded as 36.15 bar (at 11 °CA aTDC) with the use of PRF20. Additionally, as the content of iso-octane in the fuel mixture was increased, combustion delay occurred, and the maximum value of in-cylinder temperature obtained was 11 °CA aTDC using PRF20 fuel at the earliest point. While HC and CO emissions reached the highest values at a 60 °C intake air temperature, NOx and soot emission values were detected at quite low levels at this temperature. The values of all these emissions increased with rising intake manifold pressure and reached their highest values at 140 kPa. In addition, while the highest HC and CO emission values were observed with the use of PRF60 fuel, the results revealed that the control of the combustion phase in the RCCI strategy is notably affected by the premixed ratio, intake manifold pressure and intake air temperature.

The paper investigates the impact of carbon emissions on stock price returns of European listed firms. This relationship is assessed across all three emissions scopes, as well as using expecta-tions to detect if future emissions impact contemporary returns. Our findings show that firms with higher expected future emissions deliver contemporary lower returns, after controlling for market capitalization, profit, and other known return predictors. This result is statistically sig-nificant in the post Paris Agreement period with a two to three years expectation on scope 2 emissions. However, there is marginal to no significant negative relationship between current emissions and current returns. Overall, the results suggest that more Environment-minded in-vestors look further ahead and would expect lower returns from a polluting firm compared to a firm with no carbon emissions after the Paris Agreement.

Les composés organiques volatils (COV) constituent l’ensemble des composés organiques émis, sous forme gazeuse, par des matériaux émissifs. Dans le cadre du programme POPART, une recherche a été conduite afin d’évaluer le potentiel de la micro-extraction sur phase solide couplée à la chromatographie gazeuse et à la spectrométrie de masse (SPME/CG-SM), technique d’analyse non destructive, pour (i) caractériser les COV émis par les matières plastiques présentes dans les collections, (ii) évaluer leurs éventuelles nocivités pour la santé et les objets et (iii) vérifier s’il est possible d’identifier une matière plastique à partir de ses émissions. À partir d’échantillons modernes industriels et d’objets patrimoniaux, il a été possible d’identifier des composés « spécifiques » autorisant l’identification d’une famille de matière plastique voire d’un type de matière plastique, ainsi que des composés odoriférants. Associée à d’autres techniques, la SPME/ CG-SM apparaît donc comme un outil analytique pertinent pour la caractérisation de matières plastiques et la préconisation de méthodes préventives à adopter pour des plastiques émissifs. Volatile organic compounds (VOCs) constitute all of the organic compounds emitted, in gaseous form, by emissive materials. As part of the POPART programme, a study was conducted to assess the potential of sold phase micro extraction, coupled with gas chromatography and mass spectroscopy (SPME/ GC-MS), a non-destructive analysis technique, in order to (i) characterize the VOCs emitted by plastic materials present in the collections, (ii) assess potential risks for the objects and public health and (iii) verify whether it is possible to identify a plastic material from its emissions. Using samples from modern industry and objects in national collections, it was possible to identify “specific” compounds, enabling the identification of a family of plastics, or even a type of plastic material, as well as odoriferous compounds. Combined with other techniques, SPME/GC-MS thus emerges as a pertinent analytical tool for characterizing plastic materials and advocating preventive measures to be adopted for emissive plastics.

Given the significance of the transportation sector to the economy of a country, major companies and government-linked entities have invested in infrastructure and transportation services. Nonetheless, the sector faces issues relating to traffic congestion, energy consumption, and environmental impacts such as air pollution and carbon emissions. To address and analyze these issues, the current study employed microscopic modeling using the AIMSUN software, which allowed for detailed modeling and simulation. The current study examined the impacts of different operating conditions, namely: internal combustion engine vehicles (ICEVs) and electric vehicles (EVs), on energy consumption, energy savings, cost savings, and emissions traveling on a total of six (6) routes: (i) long-distance highway travel, (ii) short-distance highway travel, (iii) long-distance urban travel, (iv) short-distance urban travel, (v) long-distance suburban travel, and (vi) short-distance suburban travel. The impacts of the traffic management systems, such as traffic lights, roundabouts, and road altitude, were also analyzed in this research. The current study discovered that, on average, EVs consumed 30 percent less energy than ICEVs and a 26 percent energy cost saving for long-distance highway travel. On long-distance urban travel, EVs experienced higher energy and cost savings than ICEVs, with 86 percent and 64 percent, respectively. In addition, EVs had lower carbon dioxide emissions than ICEVs. This study concludes that EVs offer positive impacts on energy cost savings and carbon dioxide emissions reduction for all six (6) simulated routes in Malaysia compared to ICEVs, thereby contributing to the existing literature on EVs in Malaysia.

The utilization of hydrogen for reciprocating internal combustion engines remains a subject that necessitates thorough research and careful analysis. This paper presents a study on the co-combustion of hydrogen with diesel fuel and biodiesel (RME) in a compression-ignition piston engine operating at maximum load, with a hydrogen content of up to 34%. The research employed engine indication and exhaust emissions measurement to assess the engine’s performance. Engine indication allowed for the determination of key combustion stages, including ignition delay, combustion time, and the angle of 50% heat release. Furthermore, important operational parameters such as indicated pressure, thermal efficiency, and specific energy consumption were determined. The evaluation of dual-fuel engine stability was conducted by analyzing variations in the coefficient of variation in indicated mean effective pressure. The increase in the proportion of hydrogen co-combusted with diesel fuel and biodiesel had a negligible impact on ignition delay and led to a reduction in combustion time. This effect was more pronounced when using biodiesel (RME). In terms of energy efficiency, a 12% hydrogen content resulted in the highest efficiency for the dual-fuel engine. However, greater efficiency gains were observed when the engine was powered by RME. It should be noted that the hydrogen-powered engine using RME exhibited slightly less stable operation, as measured by the COVIMEP value. Regarding emissions, hydrogen as a fuel in compression ignition engines demonstrated favorable outcomes for CO, CO2, and soot emissions, while NO and HC emissions increased.

The air pollutant emissions of a motor vehicle do not only mean the emissions from the engine used for propelling the vehicle. Another possible source is the passenger compartment heater. In the focus of our research, we investigated the effect of mixing gasoline-powered cabin air and ethanol (E10, E30, E100 on a volumetric basis) on the emissions of the equipment. Among the pollutant components examined, there were conventional components and so called not-conventional components. The chosen length of the test was 1800 s, while the intake air parameters temperature (tin) and relative humidity (h) have been kept constant (tin = 15 °C, h = 30%). Bioethanol mixing has a significant reducing effect on NOx (oxides of nitrogen) and CO2 (carbon dioxide). As for the components CO (carbon monoxide), THC (total hydrocarbons), CH4 (methane) and N2O (nitrous oxide), the values of the components reach usable values only in the start-up and burnout phases, while in the stable-operation phase, their values are outside the limit of detectability. A small part of THC is only CH4; a more significant part is NMHC (non-methane hydrocarbons). The results of the developed vehicle fleet model for calculating the GHG (greenhouse gas) emissions of a vehicle fleet equipped with such a device showed that the fleet’s GHG emissions are less than 1% of the annual emissions from the combustion of transport fuel.

This study analyzes Diesel Oxidation Catalyst (DOC) and Carbon Diesel Particulate Filter (CDPF) after-treatment systems integrated into a WARTSILA W20DF marine dual-fuel engine. The CDPF was coated with a non-precious metal catalyst whose catalytic redox performance improved with increasing temperature. The carbon particulate matter combustion reached up to 12.5 mg/s at 800 K and over 20 mg/s at 900 K. Then, the W20DF running at 230 kW, 450 kW, 680 kW, and 810 kW with 1000 rpm; a Tisch 10-8xx; and an AVL SPC 478 were used to sample and analyze the carbon particulate matter (CPM) before and after DOC + CDPF. The gaseous emissions (O2, CO2, CO, HC, NOx, and NO2) were analyzed with the flue gas analyzer AVL i60. The results show that the collected carbon particulate matter simultaneously became darker as the load decreased. This study finds that the maximum amount of CPM per unit volume of exhaust gas occurs under 50% working conditions and the lowest amount under 90% working conditions. After DOC + CDPF treatment with a non-precious metal coating, the CPM was reduced by about 50%. Furthermore, this type of catalyst’s efficiency rises with the temperature increase. The CPM combustion efficiency reached up to 20 mg/s at 900 K. The other gas components in the exhaust gas before and after DOC + CDPF also changed. These research results have a significant reference value for DOC + CDPF optimization to decrease the carbon particulate matter in marine engines.

Gefördert durch den Publikationsfonds der Universität Kassel

This study assesses the biomethane (CH4) generation and greenhouse gas (GHG) emissions resulting from municipal solid waste landfilling in Phnom Penh, Cambodia, with a focus on the impact of fugitive CH4 emissions and operation processes in four landfilling scenarios: simple dumping (S1), improved management with leachate treatment (S2), engineered landfill with flaring (S3), and engineered landfill with energy recovery (S4). The study also considered the environmental benefits of carbon sequestration and landfill gas utilization. The LandGEM and IPCC FOD models were used to calculate CH4 generation over the period of 2009–2022, and it was found that approximately 18 and 21 M kg/year of CH4 were released, respectively. The energy potential from CH4 recovery was 51–61 GWh/year. Overall, GHG emissions in S2 were the highest, amounting to 409–509 M kg CO2-eq/year, while S1 had lower emissions at 397–496 M kg CO2-eq/year. Flaring-captured CH4 in S3 could reduce GHG emissions by at least 55%, and using captured CH4 for electricity production in S4 could mitigate at least 83% of GHG emissions. Electricity recovery (S4) could avoid significant amounts of GHG emissions (−52 to −63 kg CO2-eq/tMSW). The study suggests that landfill gas-to-energy could significantly reduce GHG emissions.

This paper deals with the optimization of six chosen parameters such as load, clearance of piston head, number of holes in nozzle, pressure of injection, catalysts used for reduction and oxidization in order to improve performance and minimize emissions like carbon mon oxide and oxides of nitrogen from CI engine equipped with Selective Catalytic Reduction (SCR). Artificial Neural Networks (ANN) is ultilized for the purpose of optimization. The optimized parameter set is found using a trained network. The experimental outputs are compared with the output predicted by the ANN and the results are discussed. This optimized parameter set when used in engine is found to improve performance of the engine and decrease harmful emission produced from the engine thus promoting a cleaner environment.

Fossil fuel-based energy sources in both transition and developed countries are still the main primary contributors to the environmental carbon footprint. In Indonesia, West Papua province remains to depend largely on diesel generators as its primary source of electrical energy, rather than renewable energy sources. This occurs due to multiple socio-techno-economic factors, e.g. limited research for renewable energy potential, lack of public understanding of renewable energy benefits, and a shortage of national commitment. In this article, a thorough analysis of micro hydro power potential to electrify a typical development area in West Papua is provided in order to address the abovementioned research challenges. The study introduces a method for determining the potential of micro hydropower in West Papua based on evapotranspiration, flow duration curve, and plant capacity factor. In this sense, Penman and F.J Mock approaches are proposed to calculate the evapotranspiration value and the discharge quantity respectively. In addition, a reliable discharge analysis will be conducted, which requires temperature, humidity, rainfall, solar radiation, and wind speed data. Thirty rivers have the potential to be used as micro-hydro power facilities. Based on monthly data from 2012 to 2021, a micro-hydro power potential of 4,769.97 kW with an estimated annual energy production of 13,956.09 MWh to serve a demand of 25,087.02 kWh/year is calculated. Hydropower energy can save around 7,815.4 million CERs. Local governments can construct micro-hydro power plants in distant locations to replace diesel power plants, or a hybrid system to improve service quality.

The emission of nanoscale particles from the surfaces of dental implants leads to the cumulative effect of particle complexes in the bone bed and surrounding soft tissues. Aspects of particle migration with the possibility of their involvement in the development of pathological processes of systemic nature remain unexplored. The aim of this work was to study protein production during the interaction of immunocompetent cells with nanoscale metal particles obtained from the surfaces of dental implants in the supernatants. The ability to migrate nanoscale metal particles with possible involvement in the formation of pathological structures, in particular in the formation of gallstones, was also investigated. The following methods were used: microbiological studies, X-ray microtomography, X-ray fluorescence analysis, flow cytometry, electron microscopy, dynamic light scattering, and multiplex immunofluorescence analysis. For the first time, titanium nanoparticles in gallstones were identified by X-ray fluorescence analysis and electron microscopy with elemental mapping. The multiplex analysis method revealed that the physiological response of the immune system cells, in particular neutrophils, to nanosized metal particles significantly reduced TNF-a production both through direct interaction and through double lipopolysaccharide-induced signaling. For the first time, a significant decrease in TNF-a production was demonstrated when supernatants containing nanoscale metal particles were co-cultured with proinflammatory peritoneal exudate obtained from the peritoneum of the C57Bl/6J inbred mice line for one day.

Combustion in diesel engines is focusing towards unexplored combustion concepts where innovative combustion ideas are being developed following several engine control factors. Advanced low temperature combustion engines for automotive applications are one of the improvements in this regard. The test was conducted on a single cylinder, four stroke and air cooled diesel engine. The scope of this study is to investigate the impact of EGR rate variation (25%, 35% and 45 % EGR rates) on emission reductions in PCCI-DI diesel combustion approach showing a reduction of NOx–soot trade-offs than the conventional diesel combustion approach. The PCCI-DI diesel combustion in this setup is optimized applying the algorithm of grey relational analysis together with Taguchi method. This investigational setup used a methanol port injection and advanced injection timing for PCCI formation. Emission results from different EGR settings in the optimized PCCI-DI combustion scheme were analyzed and compared using surface and contour plots. From the experiment higher EGR rate resulted a decrease in NOx productions but an increase in HC, CO and smoke due to the combustion mode of the experimental setup. The study indicated that excess EGR application should be avoided to have an optimum PCCI-DI combustion having lower emission results.

With their unique optoelectronic properties, perovskite nanocrystals are highly advantageous semiconductor materials for tailored light applications including an interaction with circularly polarized light. Although chiral perovskite nanocrystals have been obtained by the adsorption of chiral molecules, their chiroptical response is still intrinsically weak. Alternatively, perovskites have been combined with artificial chiral surfaces demonstrating enhanced chiroptical responses. However, bulk perovskite films of considerable thickness were required, mitigating the perovskite’s photoluminescence efficiency and processability. Here we developed a hybrid system of a dielectric chiral nanoantenna array that was coated with a monolayer of cubic all-inorganic lead halide perovskite nanocrystals. By tuning the thickness of the perovskite film down to one monolayer of nanocrystals, we restricted the interactions exclusively to the near-field regime. The chiral surface built of z-shaped Si nanoantennas features pronounced chiral resonances in the visible to IR region. We demonstrate that the two-photon excited photoluminescence emission of the nanocrystals can be enhanced by up to one order of magnitude in this configuration. This emission increase is controllable by the choice of the excitation wavelength and polarization with an asymmetry in emission of up to 25% upon left and right circularly polarized illumination. Altogether, our findings demonstrate a pathway to an all-optical control and modulation of perovskite light emission via strong polarization sensitive light–matter interactions in the near-field, rendering this hybrid system interesting for sensing and display technologies.

In this study, ten different blends were prepared with binary and ternary combinations of diesel, palm oil biodiesel (0 vol%, 15 vol%, 20 vol% and 30 vol%), and diethyl ether (0 vol%, 5 vol% and 10 vol%) and were tested in a diesel engine. The experiments were performed on various engine loads (500 W, 750 W, 1000 W and 1250 W) and various injection timings (25 degrees CA bTDC, 30 degrees CA bTDC and 35 degrees CA bTDC) at a fixed crankshaft speed of 3000 rpm. The prepared blends were compared in terms of exergy and exergoeconomics. It may be said that exergy efficiency and specific exergy cost of work for blends improved with increasing injection timings at high engine loads. However, at low engine loads, these parameters worsened with increasing injection timings. As a result, at 500 W, relative exergy efficiency of D70PO20DE10 was 0.57 for 25 degrees CA bTDC and 0.54 for 35 degrees CA bTDC. However, at 1250 W, this value was 0.59 for 25 degrees CA bTDC and 1.16 for 35 degrees CA bTDC. Similarly, at 500 W, relative specific exergy cost of work for D70PO20DE10 was 5.29 for 25 degrees CA bTDC and 5.94 for 35 degrees CA bTDC. However, at 1250 W, this value was 5.31 for 25 degrees CA bTDC and 2.66 for 35 degrees CA bTDC. Finally, it can be concluded that neat diesel had the best results compared to all blends considered in this study in terms of exergy and exergoeconomics.

Currently, the city of Huainan, China, is constructing its intelligent transportation system, and traffic and environmental monitoring system for efficiently and effectively monitoring and managing city traffic. DLR’s traffic information platform KeepMoving is adopted in the aforementioned system, where the existing online calibration module with SUMO has been extended in order to provide current and predicted traffic states and the resultant emission information in real-time. Accordingly, a comprehensive city-wide traffic situation can be captured and shown at the KeepMoving portal, as a decision support tool for traffic management personnel. The comparison between the real and simulated data shows a promising calibration result.

Currently, NOX emission requirements for thermal power plants and power equipment are being tightened. Regime and technical measures are being developed to improve the efficiency of fuel combustion in boilers. Due to the high cost of field studies, and in some cases the impossibility of conducting them, mathematical modeling tools allow one to work out technical and tactical measures. In this paper, the multidisciplinary STAR-CCM+ platform with GMU-45 type burners is used to simulate the combustion of gaseous fuel in a digital model of an energy boiler of the type TGME-464. By conducting numerical experiments, the possibility of reducing NOX emissions by using flue gas recirculation is considered, and the efficiency of burner devices is compared when using different embrasure configurations.

This paper analyses the influence of the type of electrode in a spark plug on exhaust gas emission. The objects of the research were the following vehicles of different years of production: the Volkswagen Beetle 1300, the Honda Nighthawk 650, the BMW e46 318i, the Hyundai i10, and the Audi A4 B6. The vehicles were powered by petrol and LPG. Spark plugs were selected for the vehicles, with different kinds of construction for the main electrodes and different numbers of poles but with similar heat values. A comparative analysis of the composition of the exhaust gas mixture was performed, depending on the set of spark plugs used. The amount of CO, HC, CO2, and O2 emissions was analysed. The results were compared with the applicable exhaust gas emission standards. Both in the case of E5 95 petrol and LPG gas, lower exhaust gas emissions were observed when iridium spark plugs were used.

Exposure to air pollution is one of the greatest environmental risks for human health. Air pollution level is significantly driven by anthropogenic emissions and meteorological conditions. To protect people from air pollutants, China has implemented clean air actions to reduce anthropogenic emissions, which has led to rapid improvement in air quality over China. Here, we evaluated the impact of anthropogenic emissions and meteorological conditions on trends in air pollutants in a coastal city (Lianyungang) in eastern China from 2015 to 2022 based on a random forest model. The annual mean concentration of observed air pollutants, including fine particles, inhalable particles, sulfur dioxide, nitrogen dioxide, and carbon monoxide, presented significant decreasing trends during 2015–2022, with dominant contributions (55–75%) by anthropogenic emission reduction. An increasing trend in ozone was observed with an important contribution (28%) by anthropogenic emissions. The impact of meteorological conditions on air pollution showed significant seasonality. For instance, the negative impact on aerosol pollution occurred during cold months, while the positive impact was in warm months. Health-risk-based air quality decreased by approximately 40% in 8 years, for which anthropogenic emission made a major contribution (93%).

Air transportation is a particularly contentious issue in climate disputes. This concern is because they emit emissions like those produced by the combustion of fossil fuels. Consequently, the aviation industry is recognized as one of the top ten emitters in the world, with emissions expected to soar. As the emissions from the industry begin to rise, the increase raises serious environmental concerns about its global impact and influence on people on the ground. When non-CO2 effects are excluded, aviation emissions began to account for 2.1% of global emissions, leading the aviation industry, national governments, civil society, and international organizations to collaborate to reduce emissions drastically. Accordingly, this led to the establishment of the International Civil Aviation Organization (ICAO), which serves as a global platform for devising laws and standards for the industry, including a comprehensive set of measures to manage greenhouse gas (GHG) emissions to reach the 2050 carbon-neutral goal. The ICAO aims to eliminate all GHG emissions using sustainable alternative fuels, advanced technology, and the world's first market-based mechanism to mitigate aviation emissions. It adopted the International Aviation Carbon Offsetting and Reduction Scheme (CORSIA) in 2016. While this market-based approach to reducing international aviation's runway emissions is viewed as a step in the right direction, more is needed to achieve the sector's required level of profound decarbonization. (CORISA). This study describes the connection between aviation and climate change. It analyses the efficacy of the policy implemented and the environmental benefits of CORSIA in addressing climate change challenges in the aviation industry and the scheme's potential to have a more significant impact and provide long-term solutions. According to the study's findings, adding a required option for binding enforcement will aid in expanding the scope of CORSIA.

This study investigated mercury pollution at two e-waste recycling sites in Ghana—Dagomba Line in Kumasi and Agbogbloshie in Accra. A total of 129 soil samples taken at 100 m and 50 m resolutions, respectively, for Dagomba Line and Agbogbloshie, were analysed for mercury using a Zeeman atomic absorption spectrometry. Mercury concentrations from the recycling sites (ranging from 0.11 to 7.57 mg/kg Dagomba Line, and 0.01–4.36 mg/kg at Agbogbloshie) were significantly higher than that of the surrounding areas (0.01–0.17 mg/kg in Kumasi and 0.01–2.18 mg/kg in Accra) and unpolluted control sites (0.05 mg/kg in Kumasi and 0.02 mg/kg in Accra). The dismantling sites at both locations had the highest mercury concentrations. Furthermore, the concentrations were significantly higher at the Dagomba Line site in Kumasi than at Agbogbloshie, even though the Dagomba Line site is relatively recent. The mercury concentrations at both sites exceeded the pollution prevention and abatement level of 0.1 mg/kg. However, the estimated human health risk showed no potential human health effects. Moreover, the mercury concentrations in water and sediment (0.12–7.69 ng/L and 0.02–0.28 ng/L for Dagomba Line and Agbogbloshie, respectively) were below the US EPA standards. Findings from this study show that e-waste recycling can contaminate the topsoil with mercury, irrespective of the scale of the activity.

We use medium-resolution JWST/NIRSpec observations from the Cosmic Evolution Early Release Science Survey to place the first constraints on dust attenuation and star formation based on Paschen lines for a sizable sample of 63 galaxies at redshifts z = 1.0-3.1. Our analysis indicates strong correlations between the Balmer decrement, H alpha/H beta, and line ratios that include Paschen lines (i.e., Pa alpha/H beta, Pa beta/H beta, and the Paschen decrement, Pa alpha/Pa beta), suggesting that the former is sensitive to the overall dust obscuration toward H ii regions in high-redshift galaxies. The line ratios are used to derive nebular reddening, E(B - V)(neb), and star formation rates (SFRs). There is marginal evidence that the SFRs deduced from Paschen lines may exceed by approximate to 25% those derived from Balmer lines alone, suggesting the presence of star formation that is optically thick in Balmer lines, though deeper observations are needed to confirm this result. Using the Paschen-line constraints on the bolometric SFRs, we reevaluate the relationship between dust obscuration and UV spectral slope, and find a reddening of the UV continuum that, on average, follows the SMC extinction curve. This analysis highlights the need for deeper spectroscopy of more representative samples to evaluate nebular dust attenuation and bolometric SFRs in high-redshift galaxies, and their relationship to the reddening of the UV continuum.

We present the first spatially resolved measurements of galaxy properties in the JWST ERO SMACS 0723 field. We perform a comprehensive analysis of five 5 < z < 9 galaxies with spectroscopic redshifts from NIRSpec observations. We perform spatially resolved spectral energy distribution fitting with Bagpipes, using six NIRCam imaging bands spanning the wavelength range 0.8–5 μm. This approach allows us to study the internal structure and assembly of the first generations of galaxies. We find clear gradients both in the empirical color maps and in most of the estimated physical parameters. We find regions of considerably different specific star formation rates across each galaxy, which points to very bursty star formation happening on small scales, not galaxy-wide. The integrated light is dominated by these bursty regions, which exhibit strong line emission, with the equivalent width of [O iii]+Hβ reaching up to ∼3000–4000 Å rest frame. Studying these galaxies in an integrated approach yields extremely young inferred ages of the stellar population (

Emission factors (EFs) of gaseous pollutants, particulate matter, certain harmful trace elements, and polycyclic aromatic hydrocarbons (PAHs) from three thermal power plants (TPPs) and semi-industrial fluidized bed boiler (FBB) were compared. EFs of particulate matter, trace elements (except Cd and Pb), benzo[a]pyrene, and benzo[b]fluoranthene exceed the upper limits specified in the EMEP inventory guidebook for all combustion facilities. The comparison of trace elements and PAHs content in fly ashes (FAs) from lignite and coal waste combustion in TPPs and FBB, respectively, as well as the potential environmental impact of FAs disposal, was performed by employing a set of ecological indicators such as crustal enrichment factor, risk assessment code, risk indices for trace elements, and benzo[a]pyrene equivalent concentration for PAHs. Sequential analysis shows that the trace elements portion is the lowest for water-soluble and exchangeable fractions. The highest enrichment levels in FAs are noticed for As and Hg. Based on toxic trace elements content, FAs from TPPs represent a very high ecological risk, whereas fly ash from FBB poses a moderate ecological risk but has the highest benzo[a]pyrene equivalent concentration, indicating its increased carcinogenic potential. Lead isotope ratios for Serbian coals and FAs can contribute to a lead pollution global database.

In this paper, the effect of nano-particles along with EGR rates was experimentally assessed on the performance and emission of a DI diesel engine fueled by biodiesel and ethanol. For this purpose, three levels of TiO2 nanoparticles (0, 40, and 60 ppm) were added to biodiesel/diesel blends in the proportions of 0, 10, and 20% biodiesel with ethanol at levels of 0, 4, and 6%. EGR rates were used at 0, 20, and 30%. A total of 31 fuel samples with different ethanol, biodiesel, TiO2 nano-additives, and EGR rates were tested at different speeds. The equation for this combination is BxEy + EGRw + TiO2z, where x, y, w, and z are the percentages of biodiesel, ethanol, EGR, and TiO2. The results showed that the mixture of B10E4 + EGR20 + TiO260, reduced the amount of NOx, CO, and HC by 10, 12.4, and 17%. Moreover, due to the significant reduction of emissions and performance improvement, the combinatory method of EGR–TiO2 nano-additives can be used as an effective formula for diesel engines fueled with ethanol/biodiesel/diesel blends.

The topic of waste combustion/co-combustion is critical, given the increasingly restrictive legal regulations regarding its environmental aspects. In this paper, the authors present the test results of selected fuels of different compositions: hard coal, coal sludge, coke waste, sewage sludge, paper waste, biomass waste and polymer waste. The authors conducted a proximate and ultimate analysis of the materials and mercury content in them and their ashes. An interesting element of the paper was the chemical analysis of the XRF of the fuels. The authors conducted the preliminary combustion research using a new research bench. The authors provide a comparative analysis of pollutant emissions—especially mercury emission—during the combustion of the material; this is an innovative element of this paper. The authors state that coke waste and sewage sludge are distinguished by their high mercury content. The value of Hg emission during the combustion depends on the initial mercury content in the waste. The results of the combustion tests showed the adequacy of mercury release compared to the emissions of other compounds considered. Small amounts of mercury were found in waste ashes. The addition of a polymer to 10% of coal fuels leads to a reduction in mercury emissions in exhaust gases.

Este trabajo busca explicar el aumento en el nivel de endeudamiento del Gobierno de Colombia como producto del cambio en las reglas que restringen las decisiones de política fiscal constitución fiscal que trajo consigo la Constitución de 1991. En él se asume que el Gobierno es un agente que sopesa los costos y los beneficios de sus decisiones en un contexto de instituciones políticas y económicas. En primer lugar se exponen los principales cambios en las reglas relacionadas con las alternativas de financiamiento del gasto del Gobierno que difieren de la deuda. Después se describen los principales cambios en las reglas del endeudamiento. Se concluye que el cambio en la situación fiscal del Gobierno es resultado de una reducción relativa del precio de la deuda frente a las demás opciones de financiamiento. This paper seeks to explain the increase in the level of Colombian Central Government debt as a result of the change in the rules that restrict the decisions of fiscal policy –i.e. fiscal constitution- involved in the new Constitution. The paper assumes that the Government is an agent that weighs the costs and benefits of its decisions in a context of political and economic institutions. First, the main changes in the rules that apply to the financing alternatives for government spending, different from debt, are shown. Then, the main changes to the rules regarding the creation of debt. Lastly, it concludes that the change in the fiscal situation of the Government is an outcome of the reduction of the relative price of debt compared with other financing options.

The amount of heat transferred from the combustion chamber directly affects the combustion efficiency. Increasing the amount of heat transfer reduces the combustion efficiency. With thermal coating methods in engines, the amount of heat transfer is reduced and the combustion efficiency is increased. However, covering the entire combustion chamber with thermal material causes an increase in the knocking tendency and worsening of emission values in spark ignition engines. With the water injection method, emission values can be reduced significantly without worsening engine performance parameters. In the study, the upper surface of the piston was partially covered with MgOZrO2 ceramic material with high heat reserve in order to increase the engine efficiency. The coated engine was sprayed with water into the intake manifold at 10%, 20% and 30% by mass of instantaneous fuel consumption. By using the two methods at the same time, improvements in performance parameters and exhaust emissions have been achieved. In the TBL piston engine, power, torque, specific fuel consumption, effective efficiency and HC emissions improve, while NOx emissions increase. In the case of water injection into the intake manifold, the increased NOx emissions decrease without any deterioration in performance parameters. Improvements were found in engine torque and effective power by 4.1%, specific fuel consumption by 3.8% and effective efficiency by 3.9% at 20% water injection rate. Compared to standard engine data, a 20% reduction was achieved in NOx emissions at 30% water injection rate. In addition, reductions of up to 33% were detected in HC emissions at 20% water spraying rate. © 2023 Gazi Universitesi Muhendislik-Mimarlik. All rights reserved.

A quantum repeater node is presented based on trapped ions that act as single photon emitters, quantum memories and an elementary quantum processor. The node’s ability to establish entanglement across two 25 km-long optical fibers independently, then to swap that entanglement efficiently to extend it over both fibers, is demonstrated. The resultant entanglement is established between telecom-wavelength photons at either end of the 50 km channel. Finally, the system improvements to allow for repeater-node chains to establish stored entanglement over 800 km at Hertz rates are calculated, revealing a near-term path to distributed networks of entangled sensors, atomic clocks and quantum processors., This work was financially supported by the START prize of the Austrian FWF project Y 849-N20, the Aus- trian FWF Standalone project QMAP with project num- ber P 34055, the Institute for Quantum Optics and Quan- tum Information (IQOQI) of the Austrian Academy Of Sciences (OeAW) and the European Union's Horizon 2020 research and innovation program under grant agree- ment No 820445 and project name 'Quantum Internet Alliance'. We acknowledge funding for V. Krutyanskiy by the Erwin Schr ̈odinger Center for Quantum Science & Technology (ESQ) Discovery Programme, for N.S. by the Commissariat `a l'Energie Atomique et aux Energies Alternatives (CEA), and for B.P.L. by the CIFAR Quan- tum Information Science Program of Canada.

Spectroscopy is the basis of many applications in chemistry; however, the basic principles of light, light–matter interaction, and the operation of spectrophotometers are rarely present in chemistry curricula at the high-school level, or they are only briefly introduced to students before focusing on analytical chemistry applications. In this work, we report the results of a study conducted over several years, aimed to design, optimise, and put into practice a didactic sequence on light phenomena such as reflection, refraction, interference, diffraction, and light dispersion, as well as the basic principles of ultraviolet–visible spectroscopy and spectroscopic instruments. Difficult concepts of light phenomena and related topics were deeply investigated, focusing on the best ways to teach them to high-school students in the framework of the content-specific components identified in the topic-specific pedagogical content knowledge theoretical model. Inquiry-based learning and interactive STEM laboratory activities were combined with a historical epistemological teaching method. Short introductory videos were also recorded to help students during the remote lessons in the COVID-19 pandemic period. In this paper, we report and discuss the research strategy used in order to design and implement the sequence of educational activities, leading to a final optimised didactic sequence that was tested in a pilot study. The main results were obtained from the experimentation with several classes in two high-school technical institutes with a chemistry and material sciences curriculum, along with a group of undergraduate students during the first part of an introductory course on molecular spectroscopy.

Stable ultra-lean combustion is an effective way for natural gas engines to reduce NOx emissions, but it also has higher requirements for ignition stability. The passive pre-chamber can effectively increase the ignition energy and extend the lean-burn limit of natural gas engines. However, the scavenging capacity of the pre-chamber limits its performance under low engine load. In this paper, several passive pre-chambers are designed, and the CFD simulation is carried out to investigate the influence of direction, number and diameter of the nozzle on the scavenging process. The discharge of residual gas in the pre-chamber is mainly affected by the nozzle diameter, which varies from 5.9% to 1% when the nozzle diameter increases from 0.8 mm to 1.6 mm. At the same time, claw-shaped electrodes are applied in the pre-chamber to increase the combustion rate, which is validated in a cylinder combustion simulation. Finally, the passive pre-chamber is tested on a 6-cylinder natural gas engine under 25% load. The results show that, under the proper ignition timing, the excess air ratio (λ) can reach 1.9 under 25% load of propulsion characteristic with a low level of cyclic variation. At this time, the NOx emission can be as low as 0.34 g/kWh without aftertreatment equipment.

The luminescence of InxGa1−xN nanowires (NWs) is frequently reported with large red-shifts as compared to the theoretical value expected from the average In content. Both compositional fluctuations and radial built-in fields were considered accountable for this effect, depending on the size, structure, composition, and surrounding medium of the NWs. In the present work, the emission properties of InGaN/GaN NWs grown by plasma-assisted molecular beam epitaxy are investigated in a comprehensive study combining ultraviolet-Raman and photoluminescence spectroscopy (PL) on vertical arrays, polarization-dependent PL on bundles of a few NWs, scanning transmission electron microscopy, energy-dispersive X-ray spectroscopy, and calculations of the band profiles. The roles of inhomogeneous In distribution and radial fields in the context of optical emission properties are addressed. The radial built-in fields are found to be modest, with a maximum surface band bending below 350 meV. On the other hand, variations in the local In content have been observed that give rise to potential fluctuations whose impact on the emission properties is shown to prevail over band-bending effects. Two luminescence bands with large positive and moderate negative polarization ratios of ≈+80% and ≤−60%, respectively, were observed. The red-shift in the luminescence is associated with In-rich inclusions in the NWs due to thermodynamic decomposition during growth. The negative polarization anisotropy is suggested to result from spontaneously formed superlattices in the In-rich regions of the NWs. The NWs show a preferred orthogonal absorption due to the dielectric boundary conditions and highlight the extreme sensitivity of these structures towards light polarization.

To monitor air pollution on roads in urban areas, it is necessary to accurately estimate emissions from vehicles. For this purpose, vehicle emission estimation models have been developed. Vehicle emission estimation models are categorized into macroscopic models and microscopic models. While the calculation is simple, macroscopic models utilize the average speed of vehicles without accounting for the acceleration and deceleration of individual vehicles. Therefore, limitations exist in estimating accurate emissions when there are frequent changes in driving behavior. Microscopic emission estimation models overcome these limitations by utilizing the trajectory data of each vehicle. In this method, the total emissions in a road segment are calculated by adding together the emissions from individual vehicles. However, most research studies consider the total vehicle emissions in a road section without considering the difference in vehicle emissions at different locations of a selected road section. In this study, a road segment between two intersections was divided into sub-sections, and energy consumption and emission generation were analyzed. Since there are unique driving behaviors depending on the section of the road segment, energy consumption and emission generation patterns were identified. The findings of this study are expected to provide more detailed and quantitative data for better modeling of energy consumption and emissions in urban areas.