Emission Components Research Articles

Energy-resolved pulse profile changes in V 0332+53: Indications of wings in the cyclotron absorption line profile

We aim to investigate the energy-resolved pulse profile changes of the accreting X-ray pulsar focusing in the cyclotron line energy range, using the full set of available observations. We applied a tailored pipeline to study the energy dependence of the pulse profiles and to build the pulsed fraction spectra (PFS) for the different observations. We also studied the profile changes using cross-correlation and lag spectra. We re-analysed the energy spectra to search for links between the local features observed in the PFS and spectral emission components associated with the shape of the fundamental cyclotron line. In the PFS data, with sufficiently high statistics, we observe a consistent behaviour around the cyclotron line energy. Specifically, two Gaussian-shaped features appear symmetrically on either side of the putative cyclotron line. These features exhibit minimal variation with source luminosity, and their peak positions consistently remain on the left and right of the cyclotron line energy. Associated with the cyclotron line-forming region, we interpret them as evidence for the resonant cyclotron absorption line wings, as predicted by theoretical models of how the cyclotron line profile should appear along the observer's line of sight. A phase-resolved analysis of the pulse in the energy bands surrounding these features enables us to determine both the spectral shape and the intensity of the photons responsible for these peaks in the PFS. Assuming these features correspond to a spectral component, we used their shapes as priors for the corresponding emission components, finding a statistically satisfactory description of the spectra. To explain these results, we propose that our line of sight is close to the direction of the spin axis, while the magnetic axis is likely orthogonal to it.

Air temperature and precipitation constraining the modelled wetland methane emissions in a boreal region in northern Europe

Abstract. Wetland methane responses to temperature and precipitation are studied in a boreal wetland-rich region in northern Europe using ecosystem process models. Six ecosystem models (JSBACH-HIMMELI, LPX-Bern, LPJ-GUESS, JULES, CLM4.5, and CLM5) are compared to multi-model means of ecosystem models and atmospheric inversions from the Global Carbon Project and upscaled eddy covariance flux results for their temperature and precipitation responses and seasonal cycles of the regional fluxes. Two models with contrasting response patterns, LPX-Bern and JSBACH-HIMMELI, are used as priors in atmospheric inversions with Carbon Tracker Europe–CH4 (CTE-CH4) in order to find out how the assimilation of atmospheric concentration data changes the flux estimates and how this alters the interpretation of the flux responses to temperature and precipitation. Inversion moves wetland emissions of both models towards co-limitation by temperature and precipitation. Between 2000 and 2018, periods of high temperature and/or high precipitation often resulted in increased emissions. However, the dry summer of 2018 did not result in increased emissions despite the high temperatures. The process models show strong temperature and strong precipitation responses for the region (51 %–91 % of the variance explained by both). The month with the highest emissions varies from May to September among the models. However, multi-model means, inversions, and upscaled eddy covariance flux observations agree on the month of maximum emissions and are co-limited by temperature and precipitation. The setup of different emission components (peatland emissions, mineral land fluxes) has an important role in building up the response patterns. Considering the significant differences among the models, it is essential to pay more attention to the regional representation of wet and dry mineral soils and periodic flooding which contribute to the seasonality and magnitude of methane fluxes. The realistic representation of temperature dependence of the peat soil fluxes is also important. Furthermore, it is important to use process-based descriptions for both mineral and peat soil fluxes to simulate the flux responses to climate drivers.

Probing red supergiant atmospheres and winds with early-time, high-cadence, high-resolution type II supernova spectra

High-cadence high-resolution spectroscopic observations of infant Type II supernovae (SNe) represent an exquisite probe of the atmospheres and winds of exploding red-supergiant (RSG) stars. Using radiation hydrodynamics and radiative transfer calculations, we studied the gas and radiation properties during and after the phase of shock breakout, considering RSG star progenitors enshrouded within a circumstellar material (CSM) that varies in terms of the extent, density, and velocity profile. In all cases, the original, unadulterated CSM structure is probed only at the onset of shock breakout, seen in high-resolution spectra as narrow, often blueshifted emission components, possibly with an additional absorption trough. As the SN luminosity rises during breakout, radiative acceleration of the unshocked CSM starts, leading to a broadening of the ``narrow'' lines by several 100 (up to several 1000) depending on the CSM properties. This acceleration is at its maximum close to the shock, where the radiative flux is greater and thus typically masked by optical-depth effects. Generally, the narrow-line broadening is greater for more compact, tenuous CSM because of the proximity to the shock where the flux is born; it is smaller in the denser and more extended CSM. Narrow-line emission should show a broadening that slowly increases first (the line forms further out in the original wind), then sharply rises (the line forms in a region that is radiatively accelerated), before decreasing until late times (the line forms further away in regions more weakly accelerated). Radiative acceleration is expected to inhibit X-ray emission during the early (IIn) phase. Although high spectral resolution is critical at the earliest times to probe the original slow wind, the radiative acceleration and the associated line broadening may be captured with medium resolution. This would allow for a simultaneous view of narrow, Doppler-broadened line emission, as well as extended, electron-scattering broadened emission.

Nebular and Nonthermal Radio Emissions for Young Stellar Populations with PARSEC v1.2s

Abstract In this paper, we compute, by means of the recently and thoroughly updated PARSE v1.2 s database of stellar nonrotating evolutionary tracks, the integrated stellar spectra, the ionizing photon budget, and the supernovae rates of young simple stellar populations (SSPs), for five metallicities between 0.0001 and 0.02 and four choices of stellar initial mass function (IMF) upper mass limits between 40 M ⊙ and 350 M ⊙. Using the photo-ionization code CLOUDY, we compute, at this same range of metallicities and limits, the intensities of some selected recombination and collisionally excited lines as a function of the age of the SSP. We account for the electron temperature dependence on IMF upper mass limit and metallicity while computing the thermal radio emission component, and also accounted for recent advances in core-collapse supernova explosion models while computing the nonthermal radio emission component. We self-consistently add the emission lines, nebular continuum, and nonthermal radio emission to the original SSP integrated photospheric spectra. Finally, from the resulting new suite of SSPs, we provide a consistent set of analytical relations between star formation rate (SFR) and ultraviolet, optical, and thermal radio luminosities that can be used to convert attenuation-corrected and dust-unaffected luminosities to SFR estimates. In a forthcoming paper, we will use our new SSP libraries as input to the state-of-the-art radiative transfer model GRAphites and SILicates to test the overall performance of these SSPs in reproducing the observed spectral energy distribution of young star-forming galaxies.

ASSESSMENT OF GREENHOUSE GAS (GHG) EMISSION LEVELS IN THE COAL MINING SERVICES SECTOR AT PT ANTAREJA MAHADA MAKMUR

The mining industry has a major influence on the increase in greenhouse gas (GHG) emissions in Indonesia, especially deforestation activities and the use of fossil energy. This makes it important to study the level of greenhouse gas emissions of a mining company so that it can determine the mitigation of reducing GHG emissions released. The research aims to assess the greenhouse gas emission levels in the coal mining services sector at PT Antareja Mahada Makmur. The study provides valuable insights into the environmental impact of coal mining activities, which is crucial for informing sustainable practices and regulatory compliance. The results of this analysis show a significant increase in total A2B and stationary sources (generators) from October 2023 to September 2024 as a source of immobile emissions. The analysis shows that carbon dioxide (CO2) gas is the most dominant component in total emissions from mobile sources (A2B). The findings of this study highlight the importance of mitigation efforts, such as improving energy efficiency and the integration of renewable energy sources, in reducing emissions in the mining sector. This research could help identify gaps and propose improvements to support companies in their mitigation efforts.

Detection of a Highly Ionized Outflow in the Quasiperiodically Erupting Source GSN 069

Quasiperiodic eruptions (QPEs) are high-amplitude, soft X-ray bursts recurring every few hours, associated with supermassive black holes. Many interpretations for QPEs were proposed since their recent discovery in 2019, including extreme mass ratio inspirals and accretion disk instabilities. But, as of today, their nature still remains debated. We perform the first high-resolution X-ray spectral study of a QPE source using the Reflection Grating Spectrometers' gratings on board XMM-Newton, leveraging nearly 2 Ms of exposure on GSN 069, the first discovered source of this class. We resolve several absorption and emission lines including a strong line pair near the N vii rest-frame energy, resembling the P-Cygni profile. We apply photoionization spectral models and identify the absorption lines as an outflow blueshifted by 1700−2900 km s−1, with a column density of about 1022 cm−2 and an ionization parameter log(ξ /erg cm s−1) of 3.9−4.6. The emission lines are instead redshifted by up to 2900 km s−1, and likely originate from the same outflow that imprints the absorption features, and covers the full 4π sky from the point of view of GSN 069. The column density and ionization are comparable to the outflows detected in some tidal disruption events, but this outflow is significantly faster and has a strong emission component. The outflow is more highly ionized when the system is in the phase during which QPEs are present, and from the limits, we derive on its location, we conclude that the outflow is connected to the recent complex, transient activity of GSN 069, which began around 2010.

Man-made fine dispersed РМ10 and РМ2.5 in ambient air as a health risk factor and an object of management: domestic and international experience (analytical review)

The aim was to review and analyze Russian and foreign research works, legal, regulatory and methodical documents that focus on investigating fine-dispersed particles in ambient air considering their influence on human health and external management of emissions. The materials were searched for in relevant databases including WoS, SCOPUS, eLIBRARY; we also examined legal, regulatory and methodical documents available at web-sites of the WHO, Russian authorities and relevant authorities of several foreign countries. Multiple epidemiological and laboratory investigations confirm substantial health hazards posed by particles smaller than 10 µm (РМ10, РМ2.5). There is evidence that fine-dispersed fractions are a persistent component in emissions from industries, energy-producing facilities, and transport. The Russian methodical base for considering fine-dispersed dusts in emissions requires upgrading and improving as regards mandatory РМ10 and РМ2.5 inclusion into methods for identifying emission structures. It is also necessary to develop and approve methods for quantification of fine-dispersed particles in industrial emissions. Access to calculation and instrumental methods for establishing РМ10 and РМ2.5 masses in emissions allows correcting inventories of emission sources and proper state regulation of emissions through establishing safety rations of sufficiency of sanitary protection zones around enterprises. It also allows creating a more qualitative system for setting emission quotas where priority chemicals are identified on the basis of assessed health risks considering substantial contributions often made to them by fine-dispersed particles.

DEPOSITION OF PRIORITY POLLUTANTS FROM MOTOR VEHICLE EMISSIONS BY SNOW COVER IN THE ROADSIDE SPACE

The microzone of chemical pollution is crucial for the level of environmental safety of road operation and their interaction with the environment – the transfer of pollutants generated by the combustion of fuels in engines and substances used in road maintenance by air and water. The chemical composition of exhaust gases entering the lower atmosphere in the human breathing zone is dangerous not only for human health but also for the formation of greenhouse gases. The environmental hazard of nitrogen compound emissions is caused by the formation of fine particulate matter (PM2.5) in the atmosphere and nitrogen deposition in ecosystems. Roadside snow cover is an extremely informative substrate for monitoring the level and characteristics of roadside pollution by motor vehicle emissions. It adsorbs emission components, which are identified in melted snow as nitrogen compounds – nitrates and ammonium ion, particles in the form of suspended solids, hydrocarbons in the form of petroleum products. These contaminants form an environmental hazard of surface wastewater generated on the roadside for soils and natural water bodies. The aim of the study is to experimentally determine the contamination of snow in the roadside area of urban and suburban roads by the main environmentally hazardous pollutants of exhaust gases immobilized in the snow cover: particles (suspended solids), hydrocarbons (petroleum products), and nitrogen compounds. An experimental study of the contamination of the snow cover in the roadside area with priority pollutants (ammonium, nitrates, suspended particles, petroleum products) from vehicle emissions was carried out. It was found that in the process of exposure of the snow cover, the concentration of all studied pollutants in it increased steadily compared to the content in atmospheric snow. With increasing distance from urban and suburban roads, snow contamination with suspended solids and petroleum products was negatively correlated. This demonstrates the level of anthropogenic load created by motor vehicle traffic in the studied areas. The concentration of nitrogen-containing compounds – ammonium nitrogen and nitrates – had a positive correlation and increased with increasing distance from the road. Thus, on the studied road sections, there was a simultaneous emission of ammonium nitrogen and nitrogen oxides, which creates a particularly dangerous environmental situation in urban areas due to the formation of PM2.5.

Magnetar emergence in a peculiar gamma-ray burst from a compact star merger

Abstract The central engine that powers gamma-ray bursts (GRBs), the most powerful explosions in the universe, is still not identified. Besides hyper-accreting black holes, rapidly spinning and highly magnetized neutron stars, known as millisecond magnetars, have been suggested to power both long and short GRBs[1–8]. The presence of a magnetar engine following compact star mergers is of particular interest as it would provide essential constraints on the poorly understood equation of state for neutron stars[9,10]. Indirect indications of a magnetar engine in these merger sources have been observed in the form of plateau features present in the X-ray afterglow light curves of some short GRBs[11,12]. Additionally, some X-ray transients lacking gamma-ray bursts have been identified as potential magnetar candidates originating from compact star mergers[7,13,14]. Nevertheless, smoking gun evidence is still lacking for a magnetar engine in short GRBs, and associated theoretical challenges have been raised[15]. Here we present a comprehensive analysis of the broad-band prompt emission data of a peculiar, very bright GRB 230307A. Despite its apparently long duration, the prompt emission and host galaxy properties are consistent with a compact star merger origin, as suggested by its association with a kilonova[16]. Intriguingly, an extended X-ray emission component shows up as the γ-ray emission dies out, signifying the likely emergence of a magnetar central engine. We also identify an achromatic temporal break in the high-energy band during the prompt emission phase, which was never observed in previous bursts and reveals a narrow jet with half opening angle of ∼3.4○(RGRB/1015 cm)−1/2, where RGRB is the GRB prompt emission radius.

Emission Characteristics and Environmental Impact of VOCs from Chemically Synthesized Pharmaceuticals in Shandong Province

Three typical chemical synthesis pharmaceutical enterprises in Shandong Province were selected as the research object, 61 volatile organic compounds （VOCs） in different emission processes were monitored, the VOCs source profile of each enterprise was established, the impact of VOCs on ozone formation potential was evaluated, and the VOCs emission factor of localized synthetic pharmaceutical enterprises was constructed. The results showed that： The average ρ（TVOCs） of the organized emissions of the three pharmaceutical enterprises varied from 6 055.46 to 10 700.10 μg·m-3 and the average ρ （TVOCs） of the unorganized emissions varied from 3 665.65 to 6 616.03 μg·m-3. Halogenated hydrocarbons were the major component of the organized emissions, with mass fractions as high as 45.23% to 56.12% and OVOCs were the primary components of the unorganized emissions, with mass fractions as high as 61.06%-83.52%. The major VOCs emission species were methanol, ethanol, 2-propanol, acetone, ethyl acetate, butyl acetate, chloromethane, carbon tetrachloride, etc. Significant differences were observed in the removal efficiency of different VOCs species by removal facilities and the treatment efficiency of halogenated hydrocarbons in RTO was the lowest. The treatment efficiency of halogenated hydrocarbon species in enterprise 2 was only 15%. According to the results of the secondary formation potential of species, OVOCs and aromatic hydrocarbons should be the key species of ozone generation, among which ethanol, propanal, 2-propanol, acetone, n-butanol, toluene, and ethyl acetate had significant effects. The annual emission of enterprises was 1.16-3.66 t·a-1 and the emission factor was 1 450-2 830 g·t-1. Enterprise 1 had the highest OVOCs emission factor, with a total of 1 132.3 g·t-1.

Investigation of Individual Pulse Emission Behaviors from Pulsar J1741–0840

We have carried out a detailed study of individual pulse emission from the pulsar J1741−0840 (B1738−08) observed using the Parkes and Effelsberg radio telescopes at the L band. The pulsar exhibits four emission components, which are not well resolved by employing multicomponent Gaussian fitting. The radio emission originates at a height of approximately 1000 km, with the viewing geometry characterized by inclination and impact angles roughly estimated at 81° and 3°, respectively. Fluctuation spectral analysis of single pulse behavior reveals two prominent periodicities, around 32 and five rotation periods. The longer periodic modulation feature is linked to nulling behavior across the entire emission window, with an updated nulling fraction of 23% ± 2% derived from pulse energy distribution via Gaussian mixture modeling. In addition to quasiperiodic nulling, the pulsar also exhibits the presence of subpulse drifting in the trailing component, with the shorter periodic feature in the fluctuation spectra related to the phenomenon of subpulse drifting, and the longitudinal separation estimated to be about 5°. Both periodic modulations show significant temporal evolution with time-dependent fluctuation power. The implications of understanding the radio emission mechanisms are discussed.

Evaluation of Several Explanations of the Strong X-Ray Polarization of the Black Hole X-Ray Binary 4U 1630-47

The Imaging X-ray Polarimetry Explorer observations of the X-ray binary 4U 1630–47 in the high soft state revealed high linear polarization degrees (PDs) rising from 6% at 2 keV to 10% at 8 keV. We discuss in this Letter three different mechanisms that impact the polarization of the observed X-rays: the reflection of gravitationally lensed emission by the accretion disk, reprocessing of the emission in outflowing plasma, and electron and ion anisotropies in the accretion disk atmosphere. We conducted detailed ray-tracing studies to evaluate the impact of the reflection of strongly gravitationally lensed emission on the PDs. Although the reflected emission can produce high PDs in the high-energy tail of the thermal emission component, we do not find models that describe the PDs and are consistent with independent estimates of the source distance. We discuss the energetics of another proposed mechanism: the emission or scattering of the X-rays in mildly relativistically moving plasma outflows. We argue that these models are disfavored as they require large mechanical luminosities on the order of, or even exceeding, the Eddington luminosity. We investigated the impact of electron and ion anisotropies but find that their impact on the observed PDs are likely negligible. We conclude with a discussion of all three effects and avenues for future research.

Dual-mode emission optical temperature sensor and white light-emitting diodes using Ca2Mg0.01Y7.73Si6O26:0.24Bi3+, 0.02Eu3+ phosphors regulated by cation-controlled crystal fields

Efficient luminescent materials with dual functionalities for WLEDs and non-contact temperature sensing remain a challenge due to limitations in luminescence efficiency and tunability. This study addresses these challenges by engineering Ca2Y8Si6O26:Bi3+ phosphors through strategic cation substitution (Ba2+, Mg2+, Lu3+, and Sc3+) and Eu3+ co-doping. The results reveal that cation substitution improves the crystal structure and enhances Bi3+ ion luminescence intensity, while Eu3+ doping introduces a red emission component, enabling single-component warm white light emission.The optimized phosphor composition, Ca2Y7.76Si6O26:0.24Bi3+, exhibits strong excitation at 332 nm and an emission peak at 499 nm. With Mg2+ and Eu3+ co-doping, Ca2Mg0.01Y7.73Si6O26:0.24Bi3+, 0.02Eu3+ achieves dual-mode temperature sensing with high sensitivity values of 0.006 % (499 nm/422 nm) and 0.029 % (618 nm/422 nm). Additionally, colorimetric analysis demonstrates a tunable shift towards warm white light emission with increasing Eu3+ concentrations.These findings underscore the potential of Ca2Mg0.01Y7.73Si6O26:0.24Bi3+, 0.02Eu3+ phosphors as a scalable solution for advancing high-performance single-component WLEDs and dual-mode temperature sensors. This research provides a practical pathway to overcoming current limitations in solid-state lighting and temperature monitoring technologies.

Real-time correction of light dilution effect for ship emission monitoring of SO2

With the rapid development of the shipping industry, ship emissions have become a focal point in environmental protection. SO2, as a major component of ship emissions, is crucial to monitor to ensure environmental compliance. SO2-sensitive ultraviolet (UV) cameras represent an advanced emerging technology for remote sensing monitoring of ship emissions. However, as monitoring distance increases, errors in the monitoring results due to the light dilution (LD) effect rise significantly. The aim of this study is to address the LD effect in SO2 monitoring for mobile pollution sources and propose a real-time correction method. Based on the atmospheric radiative transfer model and developed data processing algorithms, the method corrects the LD effect in real-time, enhancing the accuracy and reliability of SO2 UV camera monitoring. Experimental data collected from ship emissions at Yantai port are used to validate the accuracy of the correction method. Results show that the LD effect can lead to a 60% underestimation in the monitoring results at a distance of 4 km. The proposed method effectively corrects the LD effect, improves the accuracy of the monitoring results, lays the foundation for the engineering application of UV cameras in ship exhaust monitoring, and therefore promotes the wide application of UV cameras in air quality monitoring and environmental protection.

Exposure the role of hydrogen with algae spirogyra biodiesel and fuel-borne additive on a diesel engine: An experimental assessment on dual fuel combustion mode

This investigation is focused on the study of the overall performance of a single-cylinder diesel engine with the use of 99.99 % pure elemental hydrogen (H2), as a gaseous fuel and algae Spirogyra biodiesel 30 % (SBD30) with 1.5 % Di-tert Butyl Peroxide (1.5%DTBP) as cetane improver and 2 % Algae Residual Carbon Nanoparticle (2%ARCNP). During the investigation, the hydrogen flow rate was controlled by an electronic gas injector and varied in the range of 5–20 lpm in the increment of 5 lpm. Among the fuel blends SBD30 + 1.5%DTBP+2%ARCNP+15H2 acted as a good combination to reduce ID and CD; and to boost HRR, BTE, and EGT. Additionally, this resulted in a drastic decline in the emission components such as HC, CO, and smoke. However, a surge in NO was observed for all the fuel sampled by the induction of H2. For SBD30 + 1.5%DTBP+2%ARCNP+15H2 a shorter ID and CD were observed at 7.2°CA and 34.5 °CA than diesel respectively at full load. The MCP for SBD30 + 1.5%DTBP+2%ARCNP+15H2 was 81 bar which occurred at 9.2°CA, however, the HRR was 61.3 J/°CA which was 1.2 % lower than that of 20 LPM hydrogen flow rate, at full load respectively. By using hydrogen + DTBP + ARCNP, the BSFC was overall lower by about 22 % and the BTE was improved by about 36.1 %. The CO, HC, and smoke for SBD30 + 1.5%DTBP+2%ARCNP+15H2 was 64.8 %, 38.8 %, and 29.2 % lower than diesel however, the NO emission was 32.6 % higher than diesel at full load respectively.

Optimal Speed Ranges for Different Vehicle Types for Exhaust Emission Control

Controlling vehicle speed is crucial for reducing exhaust emissions and ensuring the sustainable development of road transportation. Currently, speed limits on expressways are primarily set from a safety perspective, with limited research addressing speed limits from an environmental protection standpoint. In this study, based on real-world vehicle experiments and a vehicle flow exhaust emission model, we investigated the exhaust emission characteristics of light passenger vehicles (categorized as M1) and freight vehicles (categorized as N, including N1-minivans, N2-light heavy-duty vehicles, N3-medium heavy-duty vehicles, and N4-large heavy-duty vehicles) both individually and in traffic flows at varying speeds. We take carbon monoxide (CO), nitrogen oxides (NOx), particular matter (PM), and hydrocarbons (HCs) as representative emission components. The emission rate ranking of typical exhaust factors differs between M1-light passenger vehicles and N-freight vehicles. For M1-light passenger vehicles, the order is CO > HC > NOx > PM2.5, while for N-freight vehicles, it is NOx > CO > PM2.5 > HC. Conversely, for freight vehicles, higher speeds correlate with increased exhaust emissions in general, although carbon emissions specifically decrease as the speed increases. The results indicate the following speed limits conducive to sustainable road transportation development and low exhaust and carbon emissions: 90–110 km/h for light passenger vehicles and 80–100 km/h for freight vehicles.

Synthesis and Evaluation of Photoluminescence and Scintillation Characteristics of Sn Doped HfO2–Al2O3–SiO2 Glasses

One of the ways to measure ionizing radiation is achieved by the process of converting high energy radiation into a large number of photons. To convert the ionizing radiation to photons, phosphors called a scintillator have been used. Recently, glasses have become attractive materials owing to their prominent advantages, such as low cost and easy formability, and these advantages are preferable for manufacturing scintillators. However, glass scintillators suffer from a rather low energy transfer efficiency under ionizing radiation irradiation, which results in a low light yield compared with single crystalline scintillators. Furthermore, glasses generally have a low density, which cause a reduction in X-ray absorption efficiency than single crystals. In this study, to achieve development the glass scintillator which have high sensitivity for X-rays and light-yield, we focused on Hf-containing silicate glass. Hf-based materials have only been studied mainly in the form of single crystals or ceramics, and the development of Hf- based materials into glass has not yet been reported. Recently, we have succeeded in synthesizing HfO2–Al2O3–SiO2 glasses and have reported the optical and luminescence properties of these glasses when Ce is doped. In the case of the Ce doping, the photoluminescence (PL) quantum yield (QY) was ~20% and the scintillation light yield was only a few hundred ph/MeV, indicating that there is room for improvement. Thus, to improve luminescence performance, we focused on Sn, which is known to show high luminescence efficiency in glass as a luminescent center. In this study, we have synthesized and investigated optical, photoluminescence, and scintillation properties of 10HfO2–10Al2O3–80SiO2 with various concentration of Sn, therefore, we will report these results and discussions in our presentation. The glass samples were synthesized by using a floating-zone (FZ) melting furnace. HfO2 (3N, Rare Metallic Co., LTD.), Al2O3 (4N, High Purity Chemicals), SiO2 (4N, Rare Metallic Co., LTD.), and SnO (2N、High Purity Chemicals) were used as raw powders, and the materials were mixed homogeneously using a mortar. The mixed powders were formed into rod shapes by applying hydrostatic pressure and sintered in an electric furnace at 1200 ºC for 8 hours to obtain the sintered compacts. The sintered compacts were loaded into an FZ-method melting furnace, and glass samples were obtained by melting and quenching it. The samples were evaluated by density measurement, differential thermal analysis, and X-ray diffraction measurement for physical properties and structural analysis, and Raman spectra, transmission spectra, PL excitation and emission spectra, PL absolute QY, and PL decay curves were measured for optical property evaluation. Scintillation spectra and scintillation decay curves under X-ray irradiation were measured for samples that exhibited luminescence, and pulse height spectra were also measured as an evaluation of scintillation light yield. Only the emission characteristics are outlined here. All of the synthesized glass samples showed emission attributed to Sn2+, and their tendency to increase PL QY with increasing Sn concentration. X-ray induced scintillation spectra showed the characteristic emission bands of Sn2+ peaking at around 390 nm as well as the PL spectra. The peak wavelength of the spectrum shifts to the longer wavelength side with increasing Sn concentration in the glass. The disappearance of the short wavelength emission component with increasing Sn concentration in the glass can be attributed to self-absorption by Sn2+. The estimated scintillation light yield from pulse height spectrum measurements under γ-ray (137Cs) irradiation (Figure) was ~420 ph/MeV, approximately 10% of the GS10 glass scintillator counterpart. Figure 1

JWST Observations of Young protoStars (JOYS). Overview of gaseous molecular emission and absorption in low-mass protostars

The Mid-InfraRed Instrument (MIRI) on board the James Webb Space Telescope (JWST) allows one to probe the molecular gas composition at mid-infrared (mid-IR) wavelengths with unprecedented resolution and sensitivity. It is important to study these features in low-mass embedded protostellar systems, since the formation of planets is thought to start in this phase. Previous studies were sensitive primarily to high-mass protostars. The aim of this paper is to derive the physical conditions of all gas-phase molecules detected toward a sample of 18 low-mass protostars as part of the JWST Observations of Young protoStars (JOYS) program and to determine the origin of the molecular emission and absorption features. This includes molecules such as CO$_2$, C$_2$H$_2$, and CH$_4$ that cannot be studied at millimeter wavelengths. We present JWST/MIRI data taken with the Medium Resolution Spectrometer (MRS) of 18 low-mass protostellar systems, focusing on gas-phase molecular lines in spectra extracted from the central protostellar positions. The column densities and excitation temperatures were derived for each molecule using local thermodynamic equilibrium (LTE) slab models. Ratios of the column densities (absorption) or total number of molecules (emission) were taken with respect to H$_2$O in order to compare these to ratios derived in interstellar ices. Continuum emission is detected across the full MIRI-MRS wavelength toward 16/18 sources; the other two sources (NGC 1333 IRAS 4B and Ser-S68N-S) are too embedded to be detected. The MIRI-MRS spectra show a remarkable richness in molecular features across the full wavelength range, in particular toward B1-c (absorption) and L1448-mm (emission). Besides H$_2$, which is not considered here, water is the most commonly detected molecule (12/16) toward the central continuum positions followed by CO$_2$ (11/16), CO (8/16), and OH (7/16). Other molecules such as 13CO$_2$, C$_2$H$_2$, 13CCH$_2$, HCN, C$_4$H$_2$, CH$_4$, and SO$_2$ are detected only toward at most three of the sources, particularly toward B1-c and L1448-mm. The JOYS data also yield the surprising detection of SiO gas toward two sources (BHR71-IRS1, L1448-mm) and for the first time CS and NH$_3$ at mid-IR wavelengths toward a low-mass protostar (B1-c). The temperatures derived for the majority of the molecules are 100--300 K, much lower than what is typically derived toward more evolved Class II sources ($ K). Toward three sources (e.g., TMC1-W), hot ($ K) H$_2$O is detected, indicative of the presence of hot molecular gas in the embedded disks, but such warm emission from other molecules is absent. The agreement in abundance ratios with respect to H$_2$O between ice and gas points toward ice sublimation in a hot core for a few sources (e.g., B1-c), whereas their disagreement and velocity offsets hint at high-temperature (shocked) conditions toward other sources (e.g., L1448-mm, BHR71-IRS1). Molecular emission and absorption features trace various warm components in young protostellar systems, from the hot core regions to shocks in the outflows and disk winds. The typical temperatures of the gas-phase molecules of $100-300$ K are consistent with both ice sublimation in hot cores as well as high-temperature gas phase chemistry. Molecular features originating from the inner embedded disks are not commonly detected, likely because they are too extincted even at mid-IR wavelengths by small, unsettled dust grains in upper layers of the disk.

Dynamic linkages between element input structure, global value chain, and carbon emissions: evidence from a heterogeneous panel cointegration model

ABSTRACT Industrial CO2 constitutes a dominant component of global CO2 emissions. Therefore, modifications in industrial production processes are crucial. We analyse global cross-national panel datasets from 1995 to 2018 using the panel autoregressive distributed lag (ARDL) model to provide comprehensive evidence of the combined effects of input-side element structures and production-side global value chain (GVC) divisions on output-side CO2 emissions. The results show that: (i) Renewable energy and service elements in production factors can reduce CO2 emissions, though their abatement effects vary. Both can produce sustained carbon mitigation effects in the long term, but only renewable energy is effective in the short term. (ii) The GVC division pattern can induce a CO2 emission increase in both the short and long term, though these effects are heterogeneous depending on the differences in forward-backward GVC divisions. (iii) A path dependence analysis shows that input-side element structures can change production-side GVC divisions, thereby affecting output-side emissions. This study extends our understanding of the environmental effects of various production links and helps coordinate high-quality economic development and impending environmental constraints.

Displacement Factors for Aerosol Emissions From Alternative Forest Biomass Use

ABSTRACTSubstituting alternative materials and energy sources with forest biomass can cause significant environmental consequences, such as alteration in the released emissions which can be described by displacement factors (DFs). Until now, DFs of wood‐based materials have included greenhouse gas (GHG) emissions and have been associated with lower fossil and process‐based emissions than non‐wood counterparts. In addition to GHGs, aerosols released in combustion processes, for example, alter radiative forcing in the atmosphere and consequently have an influence on climate. In this study, the objective was to quantify the changes in the most important aerosol emission components for cases when wood‐based materials and energy were used to replace the production of high‐density polyethylene (HDPE) plastic, common fossil‐based construction materials (concrete, steel and brick), non‐wood textile materials and energy produced by fossil fuels and peat. For this reason, we expanded the DF calculations to include aerosol emissions of total suspended particles (TSP), respirable particulate matter (PM10), fine particles (PM2.5), black carbon (BC), nitrogen oxides (NOx), sulphur dioxide (SO2) and non‐methane volatile organic compounds (NMVOCs) based on the embodied energies of materials and energy sources. The DFs for cardboard implied a decrease in BC, SO2 and NMVOC emissions but an increase in the other emission components. DFs for sawn wood mainly indicated higher emissions of both particles and gaseous emissions compared to non‐wood counterparts. DFs for wood‐based textiles demonstrated increased particle emissions and reduced gaseous emissions. DFs for energy biomass mainly implied an increase in emissions, especially if biomass was combusted in small‐scale appliances. Our main conclusion highlights the critical need to thoroughly assess how using forest biomass affects aerosol emissions. This improved understanding of the aerosol emissions of the forestry sector is crucial for a comprehensive evaluation of the climate and health implications associated with forest biomass use.