Search Results (57)

Convective updrafts are one of the main characteristics of convective clouds, responsible for the convective mass flux and the redistribution of energy and condensate in the atmosphere. During the early stages of their lifecycle, convective clouds experience rapid cloud-top ascent manifested by a decrease in the geostationary IR brightness temperature ($T{B}_{IR}$). Under the assumption that the convective cloud top behaves like a black body, the ascent rate of the convective cloud top can be estimated as (${\displaystyle \frac{\partial T{B}_{IR}}{\partial t}}$), and it can be used to infer the near cloud-top convective updraft. The temporal resolution of the geostationary IR measurements and non-uniform beam-filling effects can influence the convective updraft estimation. However, the main shortcoming until today was the lack of independent verification of the strength of the convective updraft. Here, Doppler radar observations from the ESCAPE and TRACER field experiments provide independent estimates of the convective updraft velocity at higher spatiotemporal resolution throughout the convective core column and can be used to evaluate the updraft velocity estimates from the IR cooling rate for limited samples. Isolated convective cells were tracked with dedicated radar (RHIs and PPIs) scans throughout their lifecycle. Radial Doppler velocity measurements near the convective cloud top are used to provide estimates of convective updrafts. These data are compared with the geostationary IR and VIS channels (from the GOES satellite) to characterize the convection evolution and lifecycle based on cloud-top cooling rates. Full article

Transient increments of X-ray radiation and extreme ultraviolet (EUV) during solar flares are strong drivers of thermospheric dynamics on Mars, yet their class-dependent impacts remain poorly measured. This work provides the first direct, side-by-side study of Martian thermospheric reactions to flares X8.2 on 10 September 2017 and M6.0 on 17 September 2017. This study shows nonlinear, class-dependent effects, compositional changes, and recovery processes not recorded in previous investigations. Species-specific responses deviated significantly from irradiance proportionality, even though the soft X-ray flux in the X8.2 flare was 13 times greater. Argon (Ar) concentrations rose 3.28× (compared to 1.13× for M6.0), and radiative cooling led CO₂ heating to approach a halt at ΔT = +40 K (X8.2) against +19 K (M6.0) at exobase altitudes (196–259 km). N₂ showed the largest class difference, where temperatures rose by +126 K (X8.2) instead of +19 K (M6.0), therefore displaying flare-magnitude dependent thermal sensitivity. The 1.95× increase in O concentrations during X8.2 and the subsequent decrease following M6.0 (−39 K cooling) illustrate the contradiction between photochemical production and radiative loss. The O/CO₂ ratio at 225 km dropped 46% during X8.2, revealing compositional gradients boosted by flares. Recovery timeframes varied by class; CO₂ quickly re-equilibrated because of effective cooling, whereas inert species (Ar, N₂) stabilized within 1–2 orbits after M6.0 but needed >10 orbits of the MAVEN satellite after the X8.2 flare. The observations of the X8.2 flare came from the western limb of the Sun, but the M6.0 flare happened on the far side. The CME shock was the primary driver of Mars’ EUV reaction. These findings provide additional information on atmospheric loss and planetary habitability by indicating that Mars’ thermosphere has a saturation threshold where strong flares induce nonlinear energy partitioning that encourages the departure of lighter species. Full article

The dynamic relationship between microplastics (MPs) in the air and on the Earth’s surface involves both natural and anthropogenic forces. MPs are transported from the ocean to the air by bubble scavenging and sea spray formation and are released from land sources by air movements and human activities. Up to 8.6 megatons of MPs per year have been estimated to be in air above the oceans. They are distributed by wind, water and fomites and returned to the Earth’s surface via rainfall and passive deposition, but can escape to the stratosphere, where they may exist for months. Anthropogenic sprays, such as paints, agrochemicals, personal care and cosmetic products, and domestic and industrial procedures (e.g., air conditioning, vacuuming and washing, waste disposal, manufacture of plastic-containing objects) add directly to the airborne MP load, which is higher in internal than external air. Atmospheric MPs are less researched than those on land and in water, but, in spite of the major problem of a lack of standard methods for determining MP levels, the clothing industry is commonly considered the main contributor to the external air pool, while furnishing fabrics, artificial ventilation devices and the presence and movement of human beings are the main source of indoor MPs. The majority of airborne plastic particles are fibers and fragments; air currents enable them to reach remote environments, potentially traveling thousands of kilometers through the air, before being deposited in various forms of precipitation (rain, snow or “dust”). The increasing preoccupation of the populace and greater attention being paid to industrial ecology may help to reduce the concentration and spread of MPs and nanoparticles (plastic particles of less than 100 nm) from domestic and industrial activities in the future. Full article

Exploration practice has proved that preservation conditions are one of the critical factors contributing to shale gas enrichment in the Middle Yangtze area. Well Yidi2 is the discovery well of Cambrian shale gas in this area. The paleo-fluid evolution and its implication for preservation conditions of shale gas remains unclear, posing challenges for shale gas exploration and development. In this study, through systematic analysis of fluid inclusions in fractrue-filling vein of the entire core section of this well, combined with carbon and oxygen isotope tests of veins and host rocks, a paleo-fluid profile was established to explore the formation environment of Cambrian paleo-fluids and their implications for the preservation conditions of the Shuijingtuo Formation (SJT Fm.) shale gas. The results suggest that fractures in the SJT Fm. shale at the base of Cambrian Series 2 mainly formed during the deep burial hydrocarbon generation stage, trapping a large number of liquid hydrocarbon inclusions. Subsequently, numerous high-density methane inclusions and a few of gas-liquid two-phase inclusions were trapped. The SO₄²⁻, Ca²⁺ and Mg²⁺ content of fluid inclusion groups in the veins decreased from the Qinjiamiao Formation (QJM Fm.) at the bottom of Cambrian Series 3 upward and downward respectively, and the rNa⁺/rCl⁻ ratio was the lowest in the SJT Fm. and increased overall upward. The δ¹³C values of calcite veins in Tianheban Formation (THB Fm.)-Shipai Formation (SP Fm.) of the middle Cambrian Series 2 and the Loushanguan Formation (LSG Fm.) of the Cambrian Series 3 were lighter compared to the host rocks. Results indicate the later tectonic activities in this area were relatively weak, and the shale interval remained in a state of high gas saturation for a long time. The QJM Fm. was the main source of high-salinity brine, and the SJT Fm. had strong self-sealing properties and was relatively less affected by external fluids. However, the pressure evolution of high-density methane inclusions in the SJT Fm. indicated that the pressure coefficient of the shale section significantly decreased during the Indosinian uplift and erosion stage. The veins in the THB-SP and LSG Fms. were closely related to the oxidation of hydrocarbon gases by TSR (thermochemical sulfate reduction) and the infiltration of atmospheric water, respectively. Therefore, the paleo-fluid in the fractures of Well Yidi2 have integrally recorded the whole geological process including the evolution from oil to gas, the backflow of high-salinity formation water, the upward escape of shale gas, and the process of shale gas reservoirs evolving from overpressure to normal pressure. Considering that Well Yidi2 area is located in a relatively stable tectonic setting, widely distributed fracture veins probably enhance the self-sealing ability, inhibiting the rapid escape of SJT Fm. shale gas. And the rapid deposition of Cretaceous also delayed the loss of shale gas to some extent. The combination of these two factors creates favorable preservation conditions of shale gas, establishing the SJT Fm. as the primary exploration target in this area. Full article

Spray scrubbers are widely used in gas purification applications and allow fulfillment of the demands of air quality norms introduced all over the world. They effectively remove harmful gases like sulfur dioxide (SO₂), nitrogen oxides (NO_x), and particulate matter from industrial emissions, reducing their impact on air quality. Moreover, by capturing greenhouse gases such as carbon dioxide (CO₂) in certain applications, spray scrubbers contribute to efforts to reduce climate change. Optimization of scrubber internal elements leads to reduced energy usage and lowered water mass flow while maintaining high pollutant removal efficiency. This makes them cost-effective in the long term. The demister is an additional device which is often used in scrubbing systems, and its main task is to prevent the water droplets from escaping through the upper part of the scrubbing chamber. In this article, the pollution (MgO particles) is introduced to the system upstream the scrubber inlet, the working fluid is air under atmospheric pressure, and water droplets are generated by a single nozzle placed inside the scrubber. Before the experimental part, a preliminary numerical analysis of gas velocity inside scrubber is performed and expectations of particle behavior are indicated. Then, the authors present the spray scrubber laboratory stand designed by them and carry out experimental research on it. Each element of the test stand is described in the article including the self-designed fluidizer, which effectively mixes MgO powder with air. The authors investigate the effect of their innovative construction of demister on separation efficiency and compare the results to the case without demister. The impact of water mass flow rate generated by the nozzle and gas inlet velocity on separation efficiency is presented for several investigated cases. The results show that demisters significantly improve the separation efficiency at lower water mass flow rates and successfully prevent water droplets from reaching the scrubber outlet. The measured separation efficiency was in the range of 80% for lower water mass flow rates up to 97% for the highest water flows. Full article

Ariel (Atmospheric Remote-sensing Infrared Exoplanet Large-survey) is the ESA Cosmic Vision M4 mission, selected in March 2018 and officially adopted in November 2020, whose launch is scheduled by 2029. It aims at characterizing the atmospheres of hundreds of exoplanets orbiting nearby stars by low-resolution primary and secondary transit spectroscopy. The Ariel spacecraft’s operational orbit is baselined as a large-amplitude, eclipse-free halo orbit around the second Lagrangian (L2) point, a virtual point located at about 1.5 million km from the Earth in the anti-Sun direction, as it offers the possibility of long uninterrupted observations in a fairly stable radiative and thermo-mechanical environment. A direct escape injection with a single passage through the Van Allen radiation belts is foreseen. During both the injection trajectory and the final orbit around L2, Ariel will be immersed in and interact with Sun radiation and the plasma environment. These interactions usually result in the accumulation of net electrostatic charge on the external surfaces of the spacecraft, leading to a potentially hazardous configuration for the nominal operation and survivability of the Ariel platform and its payload, as it may induce harmful electrostatic discharges (ESDs). This work presents the latest results collected from surface charging analyses conducted using the SPIS tool of the European SPINE community along the GEO insertion orbit segment and operational orbit. Full article

Attributed to the lack of an Earth-like global intrinsic dipole magnetic field on Mars, the induced electromagnetic field environment plays a crucial role in the evolution of its atmosphere. The dominant motional electric field (${\mathit{E}}_{\mathit{M}}$) induced by the bulk motion of the magnetic field within the Martian magnetosheath serves to accelerate ions toward escape velocity, thereby forming a plume escape channel. However, the distribution morphology of ${\mathit{E}}_{\mathit{M}}$ itself has received limited attention in previous research. In this study, by taking advantage of the multi-fluid Hall-MHD model cooperating with the Martian crustal field model, we focus on elucidating the physical mechanisms underlying the asymmetrical distribution of ${\mathit{E}}_{\mathit{M}}$ and examining the influence of the crustal field on this asymmetry. The results obtained from the simulation conducted in the absence of the crustal field indicate that the ${\mathit{E}}_{\mathit{M}}$ is more intense within the ${-Z}_{MSE}$ magnetosheath, where ${\mathit{E}}_{\mathit{M}}$ is directed toward Mars, primarily due to its corresponding higher velocity and a stronger magnetic field at lower solar zenith angles. The Martian crustal field has the ability to enhance the local ${\mathit{E}}_{\mathit{M}}$ around the inner boundary of the magnetosheath by amplifying both the magnetic field and its associated velocity. Accordingly, these findings provide valuable insights into the asymmetric nature of ${\mathit{E}}_{\mathit{M}}$ within the Martian magnetosheath under typical quiet-time solar wind conditions. Full article

Despite decreasing anthropogenic mercury (Hg) emissions in Europe and the banning and restriction of many persistent organic pollutants (POPs) under the Stockholm Convention, Mediterranean marine mammals still have one of the highest body burdens of persistent pollutants in the world. Moreover, the Mediterranean basin is one of the most sensitive to climate change, with likely changes in the biogeochemical cycle and bioavailability of Hg, primary productivity, and the length and composition of pelagic food webs. The availability of food resources for marine mammals is also affected by widespread overfishing and the increasing number of alien species colonizing the basin. After reporting the most recent findings on the biogeochemical cycle of Hg in the Mediterranean Sea and the physico-chemical and bio-ecological factors determining its exceptional bioaccumulation in odontocetes, this review discusses possible future changes in the bioavailability of the metal. Recent ocean–atmosphere–land models predict that in mid-latitude seas, water warming (which in the Mediterranean is 20% faster than the global average) is likely to decrease the solubility of Hg and favor the escape of the metal to the atmosphere. However, the basin has been affected for thousands of years by natural and anthropogenic inputs of metals and climate change with sea level rise (3.6 ± 0.3 mm year⁻¹ in the last two decades), and the frequency of extreme weather events will likely remobilize a large amount of legacy Hg from soils, riverine, and coastal sediments. Moreover, possible changes in pelagic food webs and food availability could determine dietary shifts and lower growth rates in Mediterranean cetaceans, increasing their Hg body burden. Although, in adulthood, many marine mammals have evolved the ability to detoxify monomethylmercury (MMHg) and store the metal in the liver and other organs as insoluble HgSe crystals, in Mediterranean populations more exposed to the metal, this process can deplete the biological pool of Se, increasing their susceptibility to infectious diseases and autoimmune disorders. Mediterranean mammals are also among the most exposed in the world to legacy POPs, micro- and nanoplastics, and contaminants of emerging interest. Concomitant exposure to these synthetic chemicals may pose a much more serious threat than the Se depletion. Unfortunately, as shown by the literature data summarized in this review, the most exposed populations are those living in the NW basin, the main feeding and reproductive area for most Mediterranean cetaceans, declared a sanctuary for their protection since 2002. Thus, while emphasizing the adoption of all available approaches to mitigate anthropogenic pressure with fishing and maritime traffic, it is recommended to direct future research efforts towards the assessment of possible biological effects, at the individual and population levels, of chronic and simultaneous exposure to Hg, legacy POPs, contaminants of emerging interest, and microplastics. Full article

The objective of this study was to evaluate the extent of radon contamination in twenty-six drinking water samples from natural springs were collected from Dhirkot Azad Kashmir, along with four bottled mineral water samples. Radon gas escapes from the earth’s crust due to uranium ores and diffuses into the atmosphere. This study assessed the levels of radon concentration, the yearly effective radiation dose, and carcinogenic risk from radon exposure in drinking water samples. The radon concentration varied from 0.28 to 30.25 Bq/L. The mean radon concentration of all samples was found to be 7.86 ± 2.3 Bq/L. The radon concentrations in bottled drinking water were found to be lower than those in natural springs. The statistical and GIS analyses included the use of interpolation and Pearson’s correlation matrix. Seven samples had radon concentration that surpassed the standard limit established by the US-EPA, which is 11 Bq/L. The average annual effective dose from inhalation and ingestion was found to be lower than the value (0.1 mSv/y) provided by the WHO, but for some natural spring water samples, it exceeded the risk limit. The cancer risk revealed that 40% of the samples had an elevated lifetime cancer risk from radon exposure. Overall, the majority of the results obtained aligned with the worldwide guidelines established by the US-EPA. However, there were a few instances where the limits were exceeded, and constant monitoring is recommended. This study establishes a baseline for radon concentration in the area and provides a basis for future studies. Full article

Currently, university students are facing high levels of stress and negativity. Creating a campus learning environment that promotes students’ physical and mental health and well-being has become a key focus of current research. There is now a wealth of research proving that the natural attributes of learning spaces are highly restorative for university students, both physically and mentally. In order to comprehensively clarify the characteristics of the library spatial environment that has a restorative effect on university students, this paper conducted semi-structured interviews with 50 university students and thematically analyzed the data obtained from these interviews. Ultimately, we identified five key themes: (1) Being away: students believe that studying alone is a way to escape social pressures, immersing themselves in their studies helps them forget everything around them, and the view from the window creates a sense of detachment; (2) Extent: students perceive the design of the library space as rich and orderly; (3) Fascination: many elements of the library spatial environment appeal to them and make them feel energized. The overall atmosphere motivates them to engage more actively in their learning; (4) Compatibility: the library spatial environment provides a variety of facilities that meet their learning needs, along with various types of spaces catering for different behaviors; and (5) Biophilia: Many interviewees mentioned the benefits of natural environments and timber, as well as their preference for spaces with a sufficient sense of enclosure and the ability to observe others. The first four themes were found to be closely related to the Attention Restorative Theory during the course of the study, while the last theme was mentioned by most of the students. The results of this study prove that library spaces can be described as restorative environments in the same way as natural environments, with both physical and mental restorative effects. Furthermore, the results of this study can also provide certain ideas for the design and renovation of the internal spatial environment of university libraries. Full article

Underground coal mining results in large goafs and numerous abandoned mines that contain substantial amounts of coalbed methane. If this methane is not used and controlled, it will escape into the atmosphere through geological fractures and can result in serious greenhouse gas effects and environmental damage. Exploring and developing the coalbed methane resources of abandoned mines can not only improve coal mine safety and protect the ecological environment but also reuse waste and mitigate energy shortages. Geophysical methods have made some progress in detecting abandoned coal mines, but there are still some challenges and difficulties. The resolution of seismic exploration may not be enough to accurately describe the details of coal seams and CBM rich areas, and the effect of resistivity method in deep CBM exploration is limited. In addition, the geological structure of abandoned coal mines is usually more complex, such as faults, folds, etc., which makes the application of exploration methods more difficult and increases the difficulty of data interpretation. Therefore, it is necessary to develop and perfect exploration technology continuously including the application of geophysical big data, deep learning, and artificial intelligence inversion to realize the accurate detection and evaluation of CBM resources in abandoned coal mines. Full article

Secondary minerals in SNC meteorites from Mars exhibit O isotope ratios believed to be consistent with the non-thermal escape of O from the atmosphere. The primary source of the non-thermal O is the dissociative- recombination of O₂⁺ in the ionosphere. I present here the results of a model that accounts for the probability of escape of non-thermal O isotopes due to collisions with overlying CO₂, combined with a model for Rayleigh fractionation of the atmosphere remaining as a result of O escape. Previous analyses of MAVEN number density data have shown a strong variability with latitude and season of the heights of the homopause and exobase, with a mean homopause at 110 km and a mean difference of about 60 km. Rayleigh model results demonstrate a dependence on homopause height and on temperature profile and require a more accurate calculation of fractionation factors for the Rayleigh equation. Isothermal temperature profiles yield much smaller variation in ¹⁷O with homopause height. These results demonstrate the need for a careful assessment of O isotope enrichment due to non-thermal escape both for the modern atmosphere and for the evolution of the atmosphere over the age of the planet. Full article

To account for changes in the performance of spillway aerator structures of high-altitude dams, depressurization generalized model experiments and theoretical analyses were conducted in this study. Measurements were taken for ventilation hole air velocity, cavity subpressure, cavity length, and air concentration in crucial regions. The study proposed correction formulas for the aeration coefficient and water air concentration in aerator devices operating under low atmospheric pressure. The pressure range of the experiments was between 26.3 kPa and 101.3 kPa. The results indicated that with decreasing atmospheric pressure, ventilation hole air velocity, ventilation volume, cavity subpressure, and water air concentration all showed a decreasing trend. For every 15 kPa decrease in pressure, ventilation hole air velocity decreased by approximately 24%. When the atmospheric pressure dropped from 101.3 kPa to 26.3 kPa, the cavity subpressure decreased and eventually approached zero. The maximum reduction in air concentration was 14.9% in the cavity backwater area, 38.5% at the cavity end, and 38.3% in the downstream bubble escape segment. The proposed correction formulas could be used for a rapid estimation of ventilation volume and air concentration in low-pressure environments. This research provides a scientific basis for the design of aeration devices in water projects located in high-altitude regions. Full article

A significant volume of literature has extensively reported on and presented the benefits of employing escape classroom games (ECGs), on one hand, and on augmented reality (AR) in English language learning, on the other. However, there is little evidence on how AR-powered ECGs can enhance deep and meaningful foreign language learning. Hence, this study presents the design, development and user evaluation of an innovative augmented reality escape classroom game created for teaching English as a foreign language (EFL). The game comprises an imaginative guided group tour around the Globe Theatre in London that is being disrupted by Shakespeare’s ghost. The game was evaluated by following a qualitative research method that depicts the in-depth perspectives of ten in-service English language teachers. The data collection instruments included a 33-item questionnaire and semi-structured interviews. The findings suggest that this escape game is a suitable pedagogical tool for deep and meaningful language learning and that it can raise cultural awareness, while enhancing vocabulary retention and the development of receptive and productive skills in English. Students’ motivation and satisfaction levels toward language learning are estimated to remain high due to the game’s playful nature, its interactive elements, as well as the joyful atmosphere created through active communication, collaboration, creativity, critical thinking and peer work. This study provides guidelines and support for the design and development of similar augmented reality escape classroom games (ARECGs) to improve teaching practices and foreign language education. Full article

In order to understand the air quality of fitness centers according to the Environmental Protection Administration’s “Indoor Air Quality Standards”, as well as to discuss how fitness center air-conditioning ventilation systems can effectively remove indoor air pollutants, this study focused on six Taichung fitness centers in a seven-sample air quality investigation, employing handheld precision instruments in space air testing and using linear regression analyses of the concentrations of indoor chemical pollutants, including factors such as temperature, relative humidity, CO₂, O₃, CO, CH₂O, TVOC, PM2.5, and PM10. The results of this research are as follows: (1) Quantity of indoor decorations: The decorative materials used in each of the sample spaces and their sources are not the same. Even with the same quantity of decorations, the concentrations of CH₂O and total volatile organic compounds (TVOCs) that escaped into the atmosphere were different across the samples, leading to a low correlation (R = 0.0316, R = −0.0976). Our findings on the influence of the fitness center’s establishment date on the concentrations of formaldehyde (CH₂O) and total volatile organic compounds (TVOCs) that escaped into the indoor air indicate that this correlation is low and insignificant (R = −0.3598, R = −0.5523), but show that the indoor concentration of formaldehyde decreases with time. (2) Occupants’ indoor activities: The CO₂ concentration generated by the static and dynamic activities of indoor occupants is not reflected in real time but will gradually accumulate, resulting in a moderate to low and insignificant correlation between the number of active occupants and the level of CO₂ (R = 0.4343). (3) The PM2.5 and PM10 sources of suspended particles are not only related to the external air and interior decoration materials, but also to coarse surfaces, which can easily attract dust accumulation. Therefore, materials made from fabric and artificial turf should be reduced in order to reduce dust accumulating on the materials’ surfaces. Full article