Gas Release Research Articles

Prediction of the pressure fluctuations in by-product gas pipeline networks in iron and steel enterprises using a spatiotemporal method

To overcome the problems of gas release, energy waste and pipeline leakage of dust erosion wear caused by the fluctuation of the by-product gas pressure in iron and steel enterprises, a 3D mathematical model of a by-product gas pipeline network was constructed in this study. Multi-condition numerical simulation analysis and spatiotemporal pressure fluctuation prediction modelling were also conducted. Firstly, the 3D mathematical model of a by-product gas pipeline network, with an error < 10%, was established by using computational fluid dynamics. Secondly, numerical simulations were conducted under multiple working conditions to study the pressure fluctuation law of the pipeline network and the erosion wear of the pipe wall. Finally, a rapid, accurate, adaptable prediction model was constructed using a spatiotemporal graph convolutional gated recurrent unit method with a combination of the numerical simulation data and pressure fluctuation law. The pressure fluctuation of the by-product gas pipeline network after a change in the blast furnace flow could be predicted in <2 s and the mean absolute percentage error of the prediction was < 2.6%.

Biomimetic Activation of N‐Nitrosamides with Red Light‐Triggered Nitric Oxide Release via Mediated Electron Transfer

Mediated electron transfer (MET) is fundamental to many biological functions, including cellular respiration, photosynthesis, and enzymatic catalysis. However, leveraging the MET process to enable the release of therapeutic gases has been largely unexplored. Herein, we report the bio‐inspired activation of a series of UV‐absorbing N‐nitrosamide derivatives (NOA) under red light exposure, enabling the quantitative release of nitric oxide (NO) gasotransmitter via an MET process. The cornerstone of our design is the covalent linkage of a 2,4‐dinitroaniline moiety, which acts as an electron mediator to the N‐nitrosamide groups. This facilitates efficient electron transfer from the excited palladium(II) meso‐tetraphenyltetrabenzoporphyrin (PdTPTBP) photocatalyst and the selective activation of NOA. Our approach has been validated with distinct photocatalysts and various N‐nitrosamides, including those derived from carbamates, amides, and ureas. Notably, the modulation of the linker length between the electron mediator and N‐nitrosamide groups serves as a regulatory mechanism for controlling NO release kinetics. Moreover, this biomimetic NO release platform demonstrates effective operation under both normoxic and hypoxic conditions, and it enables localized delivery of NO under physiological conditions, exhibiting significant anticancer efficacy within the phototherapeutic window and enhanced selectivity towards tumor cells.

Biomimetic Activation of N-Nitrosamides with Red Light-Triggered Nitric Oxide Release via Mediated Electron Transfer.

Mediated electron transfer (MET) is fundamental to many biological functions, including cellular respiration, photosynthesis, and enzymatic catalysis. However, leveraging the MET process to enable the release of therapeutic gases has been largely unexplored. Herein, we report the bio-inspired activation of a series of UV-absorbing N-nitrosamide derivatives (NOA) under red light exposure, enabling the quantitative release of nitric oxide (NO) gasotransmitter via an MET process. The cornerstone of our design is the covalent linkage of a 2,4-dinitroaniline moiety, which acts as an electron mediator to the N-nitrosamide groups. This facilitates efficient electron transfer from the excited palladium(II) meso-tetraphenyltetrabenzoporphyrin (PdTPTBP) photocatalyst and the selective activation of NOA. Our approach has been validated with distinct photocatalysts and various N-nitrosamides, including those derived from carbamates, amides, and ureas. Notably, the modulation of the linker length between the electron mediator and N-nitrosamide groups serves as a regulatory mechanism for controlling NO release kinetics. Moreover, this biomimetic NO release platform demonstrates effective operation under both normoxic and hypoxic conditions, and it enables localized delivery of NO under physiological conditions, exhibiting significant anticancer efficacy within the phototherapeutic window and enhanced selectivity towards tumor cells.

Innovative Sn-gradient sulfide solid electrolytes with superior air-stability for practical all-solid-state batteries

Sulfide solid electrolytes (SSEs) with high ionic conductivity and mechanical flexibility are considered promising Li+ transport media for all-solid-state batteries (ASSBs). However, susceptibility to moisture originating from their crystal structures degrades their inherent superior properties. In this study, we synthesized core–shell structured SSEs by inducing the growth of compounds with moisture-stable SnS44− units on the surface of Li6PS5Cl (LPSC). This Li10SnP2S12 (LSPS)@LPSC showed > 30 times higher Li+ conductivity than LPSC after exposure to dry room environment for 2 h. Additionally, the hydrolysis reaction was effectively inhibited in LSPS@LPSC, resulting in not only significant reduction of hydrogen sulfide (H2S) gas release, but the onset of its generation was also more delayed than in LPSC. Also, in LSPS@LPSC, the inhibition of P-O bond formation after moisture exposure contributes to retention of mechanical properties, as demonstrated by nano-indentation measurements: hardness changes from 1.42 GPa to 1.50 GPa for LSPS@LPSC versus from 1.21 GPa to 1.62 GPa for LPSC (dew point of −7.5 °C, 5 min). Furthermore, the Li(Ni0.8Co0.1Mn0.1)O2 cell with LSPS@LPSC exhibited excellent cycling stability comparable to that of LPSC under typical external pressure (30 MPa), and more remarkably, it showed superior cycle retention than LPSC cell under ultra-low external pressure (∼0.3 MPa).

Development of an Algorithm for Assessing the Scope of Large Forest Fire Using VIIRS-Based Data and Machine Learning

Forest fires pose a multifaceted threat, encompassing human lives and property loss, forest resource destruction, and toxic gas release. This crucial disaster’s global occurrence and impact have risen in recent years, primarily driven by climate change. Hence, the scope and frequency of forest fires must be collected to establish disaster prevention policies and conduct relevant research projects. However, some countries do not share details, including the location of forest fires, which can make research problematic when it is necessary to know the exact location or shape of a forest fire. This non-disclosure warrants remote surveys of forest fire sites using satellites, which sidestep national information disclosure policies. Meanwhile, original data from satellites have a great advantage in terms of data acquisition in that they are independent of national information disclosure policies, making them the most effective method that can be used for environmental monitoring and disaster monitoring. The Visible Infrared Imaging Radiometer Suite (VIIRS) aboard the Suomi National Polar-Orbiting Partnership (NPP) satellite has worldwide coverage at a daily temporal resolution and spatial resolution of 375 m. It is widely used for detecting hotspots worldwide, enabling the recognition of forest fires and affected areas. However, information collection on affected regions and durations based on raw data necessitates identifying and filtering hotspots caused by industrial activities. Therefore, this study used VIIRS hotspot data collected over long periods and the Spatio-Temporal Density-Based Spatial Clustering of Applications with Noise (ST-DBSCAN) algorithm to develop ST-MASK, which masks said hotspots. By targeting the concentrated and fixed nature of these hotspots, ST-MASK is developed and used to distinguish forest fires from other hotspots, even in mountainous areas, and through an outlier detection algorithm, it generates identified forest fire areas, which will ultimately allow for the creation of a global forest fire watch system.

Consequence analysis of vapour cloud explosion from the release of high-pressure hydrogen storage

Gaseous hydrogen is commonly stored under high pressures due to its low volumetric storage density. The safety concerns about its release and potential accidents, such as vapour cloud explosions, were of the highest importance in industries. This research work established a methodology for consequence analysis of compressed hydrogen releases, considering various stages of event escalation, including high-pressure gas release, gas jet dispersion, and overpressure evaluations. Specifically, compressed hydrogen release was defined as an under-expanded flow, characterised by a transition from sonic to supersonic velocities. The notional nozzle theory was employed to tackle the flow regime transition and provide revised nozzle size and gas velocity as inputs to the CFD model for gas jet dispersion. The model was validated against experimental results, exhibiting a good agreement with a deviation of less than 20%. The flammable gas mass in the cloud was determined using the dispersion model and then used for overpressure predictions. This approach proved to be more realistic than relying solely on the total hydrogen release amount. In a case study, release parameters such as release direction, wind speed and release hole size were investigated. It was observed that a downward release resulted in less gas dissipation, leading to larger overpressures compared to other release directions. Wind speed had a relatively lower impact compared to other parameters. The release hole size had the most significant influence on explosion overpressure, with the case of a larger release size (e.g., 50.8 mm) exhibiting a few hundred times higher of hazardous area compared to a small hole size (e.g., 3 mm).

Elasticity of coffee beans: A novel approach to understanding the roasting process

The influence of the roasting process on the mechanical and elastic properties of coffee has not been systematically investigated yet, although they change substantially. This is due to the initial drying of the beans under water release, the following structural changes at increasing temperature, the onset of chemical transformations and the release of gases and volatile ingredients. The resulting cellular structures determine the roasting result in a significant way. As measuring the elastic bean properties during roasting is easily and reproducibly possible, informative relationships to other roasting parameters can be established. It is thus possible to carry out an accompanying and up-to-date roasting control, which currently takes place via the color perception of the roasting master only. The measured values provide access to further information on changes in the internal bean structure and the processes during roasting.Elasticity measurements can therefore trace the roasting progress down to the depth of the beans, without being limited to the surface information of the color measurement as actually practiced.

HFIP‐Mediated Cyclodesulfurization Approach for the Synthesis of 2‐Aminobenzoxazole and 2‐Aminobenzothiazole Derivatives

AbstractA straightforward strategy for the synthesis of pharmaceutically active 2‐aminobenzoxazoles and 2‐aminobenzothiazoles is described by using 2‐aminophenols, 2‐aminothiophenols, and functionalized phenylisothiocyanates as the model substrates. The developed method proceeds through the HFIP‐promoted cyclodesulfurization process which allows for the efficient synthesis of these scaffolds at 60 °C of reaction temperature without the addition of a transition metal‐catalyst or hazardous solvents with excellent yields (up to 92 %) of product formation. This process involves HFIP‐mediated hydrogen bonding interactions with the hydroxyl and thiol moieties, leading to bond breaking and formation during the reaction, resulting in the compounds of interest and the in situ release of H2S gas.

First-time calculation of the spatial distribution of concentration and air quality index over South Africa using TROPOMI data

ABSTRACT The release of toxic gases into the atmosphere may reach concentrations that can cause undesirable health, economic, or aesthetic effects. It is therefore important to monitor the amounts of pollutants injected into the atmosphere from various sources. Most countries have a ground network with multiple measuring sites and instruments, that can measure the air quality index (AQI). However, the main challenge with the networks is the low spatial coverage. In this work, satellite data is used to calculate for the first time the spatial distribution of AQI and pollutant concentration over South Africa. The TROPOspheric Monitoring Instrument (TROPOMI) onboard Sentinel-5P data is used to calculate AQI from carbon monoxide (CO), nitrogen dioxide (NO2), ozone (O3), and sulfur dioxide (SO2) gases. The results that the month of June has the worst air quality distribution throughout the country, while March has the best air quality distribution. Overall, the results clearly show that TROPOMI has the capability to measure air quality at a country and city level. Implications: In this work, satellite data is used to calculate for the first time the spatial distribution of the air quality index (AQI) and pollutant concentration over South Africa. The TROPOspheric Monitoring Instrument (TROPOMI) onboard Sentinel-5P data is used to calculate AQI from carbon monoxide (CO), nitrogen dioxide (NO2), ozone (O3), and sulfur dioxide (SO2) gases. Currently, South Africa has a ground network of instruments that measure AQ, however, the network does not cover the whole country. In this work, we show that the use of TROPOMI can compliment the current network and provide data for the areas not covered.

Cracking of submerged beds

We investigate the phenomena of crater formation and gas release caused by projectile impact on underwater beds, which occurs in many natural, geophysical and industrial applications. The bed in our experiment is constructed of hydrophobic particles, which trap a substantial amount of air in the pores of the bed. In contrast to dry beds, the air–water interface in a submerged bed generates a granular skin that provides rigidity to the medium by producing skin over the bulk. The projectile's energy is used to reorganize the grains, which causes the skin to crack, allowing the trapped air to escape. The morphology of the craters as a function of impact energy in submerged beds exhibits different scaling laws than what is known for dry beds. This phenomenon is attributed to the contact line motion on the hydrophobic fractal-like surface of submerged grains. The volume of the gas released is a function of multiple factors, chiefly the velocity of the projectile, depth of the bed and depth of the water column.

P/N-containing SiO2 flame retardant particles formed by in-situ hydrolysis for significantly improve the flame retardancy and toughness of epoxy resins

To obtain flame retardants with more efficient and multidimensional flame retardant modes, this work formed P/N-containing silica flame retardants (PBPSi) by hydrolysis and used them in epoxy resins (EP) to give them good flame retardant properties. The hydrolyzed SiO2 flame retardant builds an integrated flame-retardant structure and a concentrated stress-bearing point, the EP has good fire resistant properties and toughness. Allowing the addition of 7-PBPSi/EPPBPSi to enable EP to achieve a UL-94 rating of V-0, and the impact strength of 5-PBPSi/EP reached 52.9 kJ/m2. In addition, PBPSi has good performance in inhibiting heat release and toxic gas release, and the PHRR and THR of 7-PBPSi/EP were reduced by 54.6 % and 24.6 %, respectively, compared with pure EP, the content of CO and CO2 also decreased. The analysis of the flame retardant mechanism indicated that PBPSi played a flame retardant role in the biphasic phase through the catalytic carbon formation in the condensed phase and the synergistic dilution of flammable gases and trapping of free radicals by P/N synergistic.

Effect of Surfactants on the Synthesis and Dissociation of Gas Hydrates

The synthesis and dissociation of methane hydrate and carbon dioxide hydrate were studied. Nonflammable gas hydrates can be used to extinguish flames in confined spaces. To increase the extinguishing efficiency, it is necessary to increase the dissociation rate (gas release rate) by using surfactant. The work investigates gas hydrates synthesized using sodium dodecyl sulfate (SDS). Experimental studies were carried out in wide ranges of surfactant concentration, the number of the stirrer revolutions and the initial water volume. To achieve the maximum rate of synthesis and dissociation, optimization of the specified parameters was performed. The influence of the key parameters on the dissociation rate was investigated experimentally and theoretically. The novelty of the work lies in solving a complex of interrelated tasks on the synthesis and dissociation of gas hydrate. It is shown that in order to achieve the maximum dissociation rate of carbon dioxide hydrate, it is necessary to optimize the following parameters: the diameter of the particles and their porosity, the porosity of the layer and the external heat flux.

Low Volume Gas-Flow Seeding For Highly Resolved Velocimetry Of The Boundary Layer

Ensuring fire safety in polymeric materials, which are inherently flammable but widely used in various industries, is of significant societal and economic importance. This study is part of a broader effort to understand polymer combustion and flame retardant effectiveness at a fundamental level. A major focus is the behavior of polymers burning along a vertical wall, a configuration chosen to study the release of flammable gases during pyrolysis, which contributes to the self-sustaining combustion reaction of a fire. This process occurs predominantly near the polymer surface within the boundary layer, requiring detailed analysis to evaluate flame retardant effectiveness. Our experimental setup replicates polymer pyrolysis using a flame-wall interaction burner with a vertical jet and a small inlet to mimic the release of flammable gases. The primary challenge in this setup is the introduction of seeding particles for Particle Image Velocimetry (PIV) measurements at low volume flow rates, which is complicated by reflections from the wall and the small flow scale relative to the main flow. To address this problem, we have developed a novel piezo-based ultrasonic seeder capable of controlled seeding at extremely low flow rates, thereby improving the accuracy of PIV measurements in non-reactive configurations. This seeder uses a piezo ring to excite a perforated metal membrane, forming uniform aerosol droplets. The design ensures a steady supply of particles, which is critical for evaluating boundary layer conditions. Our results demonstrate the seeder’s ability to maintain sufficient seeding density in the low volume flow region, facilitating detailed velocimetry analysis. The innovative seeder design proves effective in overcoming the limitations of conventional methods and provides new insights into polymer combustion processes and the role of flame retardants.

Generation of deposit-derived pyroclastic density currents by repeated crater rim failures at Stromboli Volcano (Italy)

The gravitational instability of hot material deposited during eruptive activity can lead to the formation of glowing avalanches, commonly known as deposit-derived pyroclastic density currents (PDCs). These currents can travel hundreds of metres to several kilometres from the source at exceptionally high temperatures, posing a catastrophic hazard to areas surrounding steep-slope volcanoes. The occurrence of deposit-derived PDCs is often associated with crater rim failure, which can be triggered by various factors such as magma thrust from dike injection, magma fingering, bulging or less commonly, powerful explosions. Here, the in-depth study of data from the multi-parametric monitoring network operating on Stromboli (Italy), including video surveillance, seismicity and ground deformation data, complemented by remote topographic sensing data, has facilitated the understanding of the events leading to the crater rim collapse on 9 October and 4 December 2022. The failures resulted in the remobilisation of 6.4 ± 1.0 × 103 m3 and 88.9 ± 26.7 × 103 m3 of material for the 9 October and the 4 December 2022, respectively, which propagated as PDCs along the NW side of the volcano and reached the sea in a few tens of seconds. These events were characterised by a preparatory phase marked by an increase in magmatic pressure in the preceding weeks, which correlated with an increase in the displacement rate of the volcano’s summit. There was also an escalation in explosive degassing, evidenced by spattering accompanied by seismic tremors in the hours before the collapse.These events have been interpreted as an initial increase in magma vesicularity, followed by the release of gas once percolation threshold was reached. The degassing process induced densification of the magma, resulting in increased thrust on the conduit walls due to increased magmastatic pressure. This phase coincided with crater rim collapse, often followed or accompanied by the onset of lava overflow phases. A mechanism similar to the one proposed may shed light on similar phenomena observed at other volcanoes. The analysis performed in this study highlights the need for a multi-parametric and multi-platform approach to fully understand such complex phenomena. By integrating different data sources, including seismic, deformation and remote sensing data, it is possible to identify the phenomena associated with the different phases leading to crater rim collapse and the subsequent development of deposit-derived PDCs.

Uncovering optimal carbon and boron nitride nanotube geometries for methane and hydrogen release

We screened 1651 carbon and boron nitride (BN) nanotubes to investigate methane release at 298 K and hydrogen release at 77 K through grand canonical ensemble Monte Carlo (GCMC) simulations. The effects of nanotube radius, density, and van der Waals spacing on the release quantities of these gases were explored. Our research shows that CH4 release in C(40,40) and BN(40,40) nanotubes reaches a high of 0.15 g/g, below the DOE's 0.5 g/g target. Similarly, the best nanotubes for volumetric release, C(21,9) and BN(18,18), peak at 175 cm³/cm³, below the DOE target of 330 cm³/cm³. This suggests that internal adsorption within isolated nanotubes is insufficient to meet DOE targets, highlighting the need for optimization of inter-tube van der Waals spacing. For H2, C(40,39) and BN(40,40) nanotubes are optimal for weight release, achieving up to 12.19% at a pressure of 8 MPa. This surpasses the 2025 DOE benchmark of 5.5 wt%. Meanwhile, C(28,7) and BN(24,24) nanotubes are most suitable for volumetric release. The C(28,7) nanotube, recommended for H2 storage, reaches a volumetric release quantity close to the DOE target of 0.04 kg/L at a van der Waals spacing of 1 nm. At pressures exceeding 2 MPa, the weight adsorption outside nanotubes accounts for 40–55% of the total, underscoring the pivotal role of extra-tube adsorption in gas storage capacity for both CH4 and H2. The results provide a foundation for the design of nanotube-based materials for efficient gas storage and release, with implications for clean energy applications.

Investigation of performance of potential adsorbents for emissions mitigation in a diesel generator.

Globally, the release of greenhouse gases primarily carbon dioxide (CO2) emissions to our Earth's surface has climbed by about 45% to its present atmospheric concentration rate of 420 parts per million (ppm) during the industrial era. An unprecedented rise in atmospheric CO2 concentration has been claimed to lead to significant factors such as global warming potential (GWP) and climate change effects. An increase in atmospheric CO2 concentrations is a serious threat to the environment. Recent research efforts have focused on mitigating emissionsfrom anthropogenic point sources. Adsorption-based post-combustion CO2 capture using solid adsorbents is the most effective and efficient method for mitigating gas adsorption in the exhaust system. In the current study, activated carbons are obtained from three potential biomass, namely, (i) coconut shell, (ii) rice husk, and (iii) eucalyptus wood, through a - single-stageactivation method. The prepared activated carbon materials are analyzed using proximate and ultimate analyses. Further investigations are performed using different characterization techniques to ensure their adsorption efficiency. Adsorbents are packed one after the other in an in-house fabricated double adsorption chamber and coupled to the exhaust unit of a generator. Test experiments are conducted to examine adsorbents' capture efficiency in emissions mitigation. Adsorbents' adsorption parameters are evaluated in experimental investigations. At 2.5bar and 50°C, a maximum loading capacity of samples is achieved by 4.85mmol/g, 4.58mmol/g, and 5.96mmol/g for coconut shell, rice husk, and eucalyptus wood adsorbents, respectively. With a post-combustion carbon adsorption chamber, CO2 and NO are captured about40-64% and 38-58%, respectively, for all three adsorbents. The thermodynamic parameter of isosteric heat of adsorption value is below 40kJ/mol, ensuring physisorption for all adsorbents.

Nanotube-mediated storage of methane and hydrogen: Insights from molecular simulation

We investigate the storage of methane (CH4) and hydrogen (H2) within single-walled nanotubes carbon, boron nitride (BN), and molybdenum disulfide (MoS2) nanotubes using Grand Canonical Monte Carlo (GCMC) algorithm. We observed that BN nanotubes exhibit the highest weight adsorption capacity for CH4 at 298 K, reaching up to 0.441 g/g at 8 MPa, closely aligning with the Department of Energy (DOE) target of 0.5 g/g. In contrast, MoS2 nanotubes, despite their larger radius, demonstrated the lowest weight adsorption capacity due to their higher atomic mass, with a value of 0.096 g/g at the same pressure. Volumetric adsorption capacity for CH4 was notably highest in (10,10) BN nanotubes, achieving 244 cm3/cm3 at 8 MPa, although this was still below the DOE target of 330 cm3/cm3. For hydrogen storage at 77 K, (30,30) BN nanotubes outperformed the 2025 DOE benchmarks of 5.5 wt% and 0.04 kg/L, with a weight adsorption of 12.19 wt% and a volumetric adsorption of 0.051 kg/L at 8 MPa, respectively. The adsorption heat within nanotubes showed a complex relationship with adsorption quantity, highlighting the interplay between fluid-wall and fluid-fluid interactions. The study also examines the impact of material structure on gas release, revealing a linear relationship between gas release and porosity or pore volume. The Ideal Adsorbed Solution Theory (IAST) was validated for predicting CH4/H2 mixture separations on amorphous carbon materials, and further reveals that the (30,30) BN nanotubes identified as the most suitable candidate for CH4/H2 separation, offering a balance of high CH4 adsorption capacity (20.2 mmol/g) and selectivity of 15 at 8 MPa.

Suitability of using carbon dioxide as a tracer gas for studying vehicle emission dispersion in a real street canyon

High-rise buildings form deep urban street canyons and restrict the dispersion of vehicle emissions, posing severe health risks to the public by aggravating roadside air quality. Field measurements are important for understanding the dispersion process of tailpipe emissions in street canyons, while a major challenge is the lack of a suitable tracer gas. Carbon dioxide (CO2), which is safe to the public and inexpensive to obtain, can be reliably measured by existing gas analysers. This study investigated the suitability of using CO2 as a tracer gas for characterising vehicle emission dispersion in a real-world street canyon. The tracer gas was released via a line or point source, whose dispersion was characterised by a sensors network comprising low-cost air quality sensors. The results showed that the CO2 contained in the exhaust gas of a test vehicle itself had unmeasurable effect at roadsides. Both the line and point sources produced obvious CO2 level elevations at approximately 30 s after the test vehicle passed by. In addition, for both line and point sources, the CO2 elevations were much more distinct at the roadside next to tailpipe exit than the opposite side, and were higher at 0.8 m than 1.6 m above the ground. The present study demonstrated that using CO2 as a tracer gas is feasible for investigating vehicle emission dispersion in real-world street canyons. Future studies are needed to improve the gas release rate of the developed tracer gas systems for more reliable measurements and larger street canyons.

Sublimation of volatiles from H2O:CO2 bulk ices in the context of comet 67P/Churyumov–Gerasimenko

Context. The ROSINA instrument on board the Rosetta spacecraft measured, among others, the outgassing of noble gases from comet 67P/Churyumov–Gerasimenko. The interpretation of this dataset and unravelling underlying desorption mechanisms requires detailed laboratory studies. Aims. We aim to improve our understanding of the desorption patterns, trapping, and fractionation of noble gases released from the H2O:CO2-dominated ice of comet 67P. Methods. In the laboratory, ice films of neon, argon, krypton, or xenon (Ne, Ar, Kr, and Xe) mixed in CO2:H2O were prepared at 15 K. Temperature-programmed desorption mass spectrometry is employed to analyse the desorption behaviour of the noble gases. Mass spectrometric ROSINA data of 67P were analysed to determine the fraction of argon associated with CO2 and H2O, respectively. Results. CO2 has a significant effect on noble gas desorption behaviour, resulting in the co-release of noble gases with CO2, decreasing the amount of noble gas trapped within water, shifting the pure phase noble gas peak desorption temperature to lower temperatures, and prolonging the trapping of neon. These effects are linked to competition for binding sites in the water ice and the formation of crystalline CO2. Desorption energies of the pure phase noble gas release were determined and found to be higher than those previously reported in the literature. Enhancement of the Ar/Kr and Ar/Xe ratios are at best 40% and not significantly influenced by the addition of CO2. Analysis of ROSINA mass spectrometric data shows that the fraction of argon associated with H2O is 0.53 ± 0.30, which cannot be explained by our laboratory results. Conclusions. Multicomponent ice mixtures affect the desorption behaviour of volatiles compared to simple binary mixtures and experiments on realistic cometary ice analogues are vital to understanding comet outgassing.

Red-emitting ratiometric fluorescent metal-free CO-releasing molecule triggered by visible light for controllable and trackable CO delivery and efficient treatment of cutaneous wounds

CO is a highly toxic gas but also an important gasotransmitter in the human body that regulates cell functions and shows great therapeutic effects in clinical trials. Due to the unsafe nature of directly inhaling CO gas, the controllable and trackable release and delivery of CO are currently the key and main challenges in achieving CO therapy. In this work, we developed a novel red-emitting fluorescent metal-free CO-releasing molecule (CORM) named COR-FC that can be used to release CO under visible light irradiation and deliver CO in cells safely, accompanied by ratiometric fluorescence changes. COR-FC combines coumarin and 3-hydroxy flavonoid fluorophores and shows low cytotoxicity. Under the light irradiation of 460 nm, COR-FC undergoes rapid photolysis to release CO, accompanied by a decrease in fluorescence at 630 nm and a significant enhancement in fluorescence at 520 nm. More importantly, COR-FC can release CO in cells and tissues under visible light illumination, which provides a new metal-free CORM achieving precise control with self-fluorescence tracking. The released CO showed good anti-inflammatory effects and was successfully used to promote wound healing, indicating that COR-FC has the potential to be further applied in the biomedical field.