Search Results (110)

Uranium mining generates complex multi-element contamination that affects interconnected ecosystem components, posing long-term ecological and sanitary risks; this review places these impacts in a broad environmental context and aims to synthesize current knowledge on the distribution, migration, and accumulation of uranium and associated heavy metals in water, soil, and plants. A structured analysis of international peer-reviewed literature was conducted, focusing on documented pathways of metal release from tailings and waste dumps, geochemical controls on mobility, and biological uptake by vegetation. The reviewed studies consistently show that tailings and disturbed ore-bearing strata act as persistent sources of uranium and heavy metals (e.g., Cd, Pb, Cr, Ni, Zn, Mn, As), which migrate through infiltration, acid mine drainage, and atmospheric dispersion, leading to elevated concentrations in surface and groundwater and long-term accumulation in soils. Soils function as the principal sink controlling metal bioavailability, while vegetation reflects the bioavailable fraction and exhibits pronounced species-specific accumulation patterns. These processes establish an active “soil–water–plant” transfer chain that facilitates entry of contaminants into food webs. The synthesis indicates that combined uranium and heavy metal contamination represents a sustained ecological and public health concern in uranium-mining regions and underscores the need for integrated monitoring of soils, waters, and vegetation, along with quantitative risk assessment and scientifically grounded remediation strategies. Full article

Characterizing both the CO₂ distribution and wind dynamics in the Martian mesosphere and lower thermosphere is vital for planetary atmospheric science and mission planning. In this work, we propose a novel dual-channel passive limb-viewing imaging system designed to simultaneously observe partial CO₂ column density and line-of-sight (LOS) wind speed from ultraviolet and visible airglow emissions under dayside and terminator illumination conditions. A dichroic beam splitter separates the ultraviolet and visible channels, ensuring high optical throughput and independent optimization of both subsystems. The ultraviolet channel targets O(¹S) 297.2 nm emission, a well-established Martian limb emission driven by CO₂ photodissociation under solar Lyman-α flux. By applying narrow-band imaging and brightness inversion, this channel provides quantitative constraints on CO₂ column density with a stable and well-defined response function. In the visible channel, we introduce a lens array-based compact static Michelson interferometer optimized for the O(¹S) 557.7 nm green line emission, which has been observed in the Martian dayside limb, providing Doppler wind measurements in the 60–180 km altitude range. Radiative transfer simulations using Mars Climate Database indicate retrieval precisions of ±6~8% for CO₂ column density and better than ±5 m/s for wind speed within the primary emission layer (approximately 60–160 km) under representative dayside limb conditions. This dual-parameter remote sensing concept simultaneously constrains the composition and dynamics of the Martian mesosphere and lower thermosphere region, addressing a long-standing observational gap. The compact and modular design of the system makes it well suited for future Mars orbiter payloads under nominal dayside and terminator observation geometries, providing critical data for validating global circulation models and supporting future entry, descent, and landing system design. Full article

When the breath of a passerby momentarily clouds the glass of a display window that distinctly withdraws from the urban continuum, it signals the presence of a perceptual threshold, an atmospheric interruption before resuming its path. This liminal space engages the observer not through physical entry, but through a multisensory activation. While the notion of atmosphere has been extensively theorised in architecture and environmental aesthetics, its implications remain insufficiently explored within retail design, particularly in the spatial and exhibit design perspective in the display window. Contemporary shop windows aim to engage passersby beyond mere product visibility; the need to articulate and design for atmosphere becomes more urgent. This article offers an atmospheric interpretation of the display window, understood not simply as a commercial interface or spatial facade but as a dioramic device in which all elements are staged in evocative micro-environments. Through the reinterpretation of selected historical and contemporary case studies, the research positions the display window as a privileged site for atmospheric experimentation. By framing window display design as an environmental and perceptual construct, the study contributes to the broader discourse on atmospheres, advancing the atmospheric paradigm as an operative approach for contemporary exhibit and spatial design practices. Full article

This paper describes a compact low-cost telemetry system featuring ready-made sensors and an acquisition unit based on the ESP32, which makes use of the LoRa/Wi-Fi wireless standard for communication, and autonomous fallback logging to guarantee data recovery during communication loss. Ensuring safe atmospheric re-entry requires reliable onboard monitoring of capsule conditions during descent. The system is intended for sub-orbital, low-cost educational capsules and experimental atmospheric descent missions rather than full orbital re-entry at hypersonic speeds, where the environmental loads and communication constraints differ significantly. The novelty of this work is the development of a fully self-contained telemetry system that ensures continuous monitoring and fallback logging without external infrastructure, bridging the gap in compact solutions for CubeSat-scale capsules. In contrast to existing approaches built around UAVs or radar, the proposed design is entirely self-contained, lightweight, and tailored to CubeSat-class and academic missions, where costs and infrastructure are limited. Ground test validation consisted of vertical drop tests, wind tunnel runs, and hardware-in-the-loop simulations. In addition, high-temperature thermal cycling tests were performed to assess system reliability under rapid temperature transitions between −20 °C and +110 °C, confirming stable operation and data integrity under thermal stress. Results showed over 95% real-time packet success with full data recovery in blackout events, while acceleration profiling confirmed resilience to peak decelerations of ~9 g. To complement telemetry, the TeleCapsNet dataset was introduced, facilitating a CNN recognition of descent states via 87% mean Average Precision, and an F1-score of 0.82, which attests to feasibility under constrained computational power. The novelty of this work is twofold: having reliable dual-path telemetry in real-time with full post-mission recovery and producing a scalable platform that explicitly addresses the lack of compact, infrastructure-independent proposals found in the existing literature. Results show an independent and cost-effective system for small re-entry capsule experimenters with reliable data integrity (without external infrastructure). Future work will explore AI systems deployment as a means to prolong the onboard autonomy, as well as to broaden the applicability of the presented approach into academic and low-resource re- entry investigations. Full article

BU–MIT whistler wave injection experiments, which were conducted at Arecibo Observatory, started with the joint US–USSR Active Space Plasma Program Experiment on 24 December 1989. In this experiment, a satellite-borne VLF transmitter injected radio waves at the frequency and power of 10 kHz and 10 kW. A series of controlled whistler wave experiments with the Arecibo HF heater were subsequently carried out during 1990–1998 until the HF heater was damaged by Hurricane Georges in 1998. In these ionospheric HF heating experiments, 28.5 kHz whistler waves were launched from the nearby naval transmitter (code-named NAU) located at Aguadilla, Puerto Rico. HF heater waves were used to create ionospheric ducts (in the form of parallel-plate waveguides) to facilitate the entry of NAU whistler waves from the neutral atmosphere into the ionosphere. Conjugate whistler wave propagation experiments were conducted between Arecibo, Puerto Rico and Trelew, Argentina in 1997. After 1999, whistler wave experiments in the absence of an HF heater had been conducted. Naturally-occurring large-scale ionospheric irregularities due to spread F or Traveling Ionospheric Disturbances (TIDs) were relied on to guide NAU launched 40.75 kHz whistler waves to propagate from the ionosphere further into the radiation belts, to cause 390 keV charged-particle precipitation. A train of TIDs, resulting from the 9.2 Mw earthquake off the west coast of Sumatra, Indonesia, was observed in our 26 December 2004 Arecibo experiments, about a day after the earthquake-launched tsunami waves traveled across the Indian Ocean, then into remote parts of the Atlantic Ocean. The author’s recent research efforts, motivated by Arecibo experiments, focus on Solar Powered Microwave Transmitting Systems, to simulate Solar Energy Harvesting via Solar Power Satellite (SPS) (also known as Space Based Solar Power (SBSP)) These experiments involved a large number of the author’s BU and MIT students working on theses and participating in the Undergraduate Research Opportunities Program (UROP), in collaboration with other colleagues at several universities and national laboratories. Full article

The Pułtusk meteorite, classified as an H5 ordinary chondrite, is one of the best documented Polish falls, yet some important data on its physical and thermophysical properties remain limited. This study provides new measurements and derived parameters of its physical and thermophysical properties that complement existing datasets for the Pułtusk meteorite and H chondrites in two important ways. Firstly, they cover a temperature range previously not explored. Secondly, using techniques generally applied in geology to validate the novel techniques developed recently, bulk and grain densities, porosity, and specific heat capacity were determined using the Archimedean method and differential scanning calorimetry, supported by bulk chemical analyses performed by ICP-MS and ICP-ES. The chemical composition of Pułtusk closely matches that of average H chondrites, though Fe and Ni contents are about 15–20% lower, likely due to weathering effects. Measured bulk density, grain density, and porosity are 3.30 g/cm³, 3.41 g/cm³, and 3.22%, respectively. The specific heat capacity increases from 564 to 1147 J/(kg·K) between 223 and 773 K, with 699 J/(kg·K) at 300 K. Derived thermophysical parameters include thermal conductivity, thermal diffusivity, and thermal inertia at 200 K, 300 K, and low pressure, and in ambient air. These results are consistent with previous data for H chondrites and confirm Pułtusk as a representative sample of this group. The new dataset can enhance the accuracy of models describing the Yarkovsky effect, meteoroid atmospheric entry, and the thermal evolution of ordinary chondrite parent bodies. Full article

Real-time monitoring of atmospheric emissions is critical for ensuring transparency, compliance, and rapid response to environmental risks. However, traditional systems often suffer from latency and a lack of verifiable data integrity. This paper presents AABF+, an adaptive packetization and microblock model built on a permissioned blockchain that supports intelligent emissions monitoring. The proposed system dynamically groups sensor readings into microblocks and commits them using Byzantine Fault Tolerant (BFT) consensus, enabling both high throughput and verifiable traceability. Unlike fixed-window blockchains, AABF+ adapts the microblock size and time window based on incoming data rates, balancing responsiveness and reliability. The model was implemented and experimentally evaluated in an edge-class 1 GbE testbed under real MRV (Measurement–Reporting–Verification) conditions. Results show that AABF+ achieves a median end-to-end latency of 0.96 s for single-record transactions and 3.07 s for 1000-record batches, while maintaining strong cryptographic verification of all entries. These findings demonstrate that AABF+ provides second-level data freshness with verifiable provenance, offering a practical foundation for digital environmental governance and regulatory compliance in Industry 4.0 ecosystems. Full article

The unprecedented increase in the number of objects orbiting the Earth necessitates a comprehensive characterisation of these objects to improve the effectiveness of Space Surveillance and Tracking (SST) operations. In particular, accurate knowledge of the attitude and physical properties of space objects has become critical for space debris mitigation measures, since these parameters directly influence major perturbation forces like atmospheric drag and solar radiation pressure. Characterising a space object beyond its orbital position improves the accuracy of SST activities such as collision risk assessment, atmospheric re-entry prediction, and the design of Active Debris Removal (ADR) and In-Orbit Servicing (IOS) missions. This study presents a novel approach for the simultaneous estimation of the attitude and optical reflective properties of uncontrolled space objects with known shape using light curves. The proposed method also accounts for atmospheric effects, particularly the Aerosol Optical Depth (AOD), a highly variable parameter that is difficult to determine through on-site measurements. The methodology integrates different estimation, optimisation, and data analysis techniques to achieve an accurate, robust, and computationally efficient solution. The performance of the method is demonstrated through the analysis of a simulated scenario representative of realistic operational conditions. Full article

The Signal Amplification By Reversible Exchange (SABRE) technique provides enhancement of Nuclear Magnetic Resonance (NMR) signals up to several orders of magnitude using chemical exchange of a substrate and parahydrogen on an iridium complex. Therefore, the availability of such a catalytic complex to a broader community is an absolutely vital step for dissemination of the groundbreaking SABRE methodology. The most common SABRE catalyst, which is activated in situ, is based on Ir-IMes system (IMes = 1,3-Bis(2,4,6-trimethylphenyl)imidazol-2-ylidene). Earlier approaches for the synthesis of this catalyst often relied on specialized equipment and were limited to a comparatively small scale. This, in turn, increased the barrier of entry for new scientists to the area of SABRE hyperpolarization. Here, we present a robust, inexpensive, and easy to reproduce synthetic procedure for the preparation of this SABRE catalyst, which does not require specialized inert atmosphere equipment like a glove box or Schlenk line. The synthesis was validated on the scale of several grams vs. tens of milligrams scale in the reported approaches. The resulting SABRE catalyst, [Ir(IMes)(COD)Cl], was activated in situ and further evaluated in hyperpolarization experiments resulting in signal enhancements comparable to (or higher than) those for the catalyst prepared using Schlenk line equipment. Full article

The rapid development of the space economy is posing big challenges, a major one being space debris mitigation. In this respect, the Horizon Europe EARS project aims to introduce the disruptive concept of reusability in the SmallSat market, taking a step towards a more sustainable exploitation of space. The main objective of EARS has been to outline the concept of operations (CONOPS) of a small reusable satellite and the maturation of the relevant key enabling technologies needed to guarantee safe re-entry of the satellite and its payload. In this paper, we present the preliminary design of the EARS spacecraft and its CONOPS and mission engineering with an overview of the simulations conducted to assess the aerodynamic load during spacecraft re-entry and the Plasmatron tests executed for the selection and characterization of the materials suitable for the construction of an inflatable thermal protection system to guarantee a safe atmospheric re-entry. Full article

This study characterized the aerosol changes during the April 2023 Hongseong wildfire in Chungcheongnam-do, Korea, using physical, optical, and chemical data from the Anmyeon-do Global Atmosphere Watch station. The observation period was divided into three distinct phases: immediately after the wildfire (Period I), during precipitation (Period II), and the re-entry of wildfire smoke after precipitation (Period III). During Periods I and III, the PM₁₀ mass concentrations were 75.7 ± 31.2 and 98.2 ± 55.6 µg/m³, respectively, which were approximately 2.4 and 3.1 times higher than the 2023 annual average (31.8 µg/m³) at the Anmyeon-do site. Aerosol scattering coefficients increased by factors of 4.0 and 6.9, and absorption coefficients by 5.5 and 4.2, respectively. Source apportionment using real-time data from a Monitor for Aerosols and Gases in ambient Air (MARGA) instrument combined with PCA demonstrated that aerosol emissions during Periods I and III were predominantly influenced by biomass burning sources. Analysis of PM₁₀ and PM_2.5 filter samples showed biomass burning markers, such as K⁺ and C₂O₄²⁻, increased by 5.5–31.4 times compared with those in Period II. Elevated levels of combustion-related elements, including S, K, V, and Pb, further confirmed the influence of wildfire smoke on air quality during the affected periods. Full article

Accurate trajectory control during atmospheric entry is critical for the success of Mars landing missions, where strong non-linearities and uncertain dynamics pose significant challenges to conventional control strategies. This study develops a computational framework that integrates fuzzy parameter-varying models with Lyapunov-based analysis to achieve robust trajectory stabilization of Mars entry vehicles. The non-linear longitudinal dynamics are reformulated via sector-bounded approximation into a Takagi–Sugeno fuzzy parameter-varying model, enabling systematic gain-scheduled controller synthesis. To reduce the conservatism typically associated with quadratic Lyapunov functions, a fuzzy Lyapunov function approach is adopted, in conjunction with the Full-Block S-procedure, to derive less restrictive stability conditions expressed as linear matrix inequalities. Based on this formulation, several controllers are designed to accommodate the variations in atmospheric density and flight conditions. The proposed methodology is validated through numerical simulations, including Monte Carlo dispersion and parametric sensitivity analyses. The results demonstrate improved stability, faster convergence, and enhanced robustness compared to existing fuzzy control schemes. Overall, this work contributes a systematic and less conservative control design methodology for aerospace applications operating under severe non-linearities and uncertainties. Full article

This study investigates the non-equilibrium radiation characteristics during the high-speed re-entry of a lunar-return-type capsule under rarefied atmospheric conditions. A line-by-line spectral model was developed to compute atomic emission and absorption coefficients for excited nitrogen and oxygen atoms. Coupled with the Direct Simulation Monte Carlo (DSMC) method, the Photon Monte Carlo (PMC) method was employed to solve the radiative energy transport equation. The model was validated against the FIRE II flight experiment at 1631 s and 1634 s, showing improved agreement with experimental heat flux data compared to previous numerical results. A detailed sensitivity analysis was conducted to examine the influence of spectral discretization and the number of emitted photons per computational cell. Results indicate that low spectral resolution can cause non-physical fluctuations in wall heat flux, while increasing the number of photons improves local smoothness. Optimal parameters were identified as 50,000 spectral points and 5000 photons per cell. The model was further applied to a lunar-return-type capsule re-ntering at 90 km and 95 km altitudes. It was found that radiative heating is spatially decoupled from aerodynamic heating and primarily governed by excited species concentration and line-of-sight geometry. At 90 km, radiative heating accounted for over $15.31\%$ of the aerodynamic heating, more than double that at 95 km. These results underscore the necessity of considering radiation effects in the design of thermal protection systems, particularly at high re-entry velocities and large angles of attack. Full article

We present a curated, openly accessible dataset of 71 regional meteor events simultaneously recorded by optical and infrasound instrumentation between 2006 and 2011. These events were captured during an observational campaign using the all-sky cameras of the Southern Ontario Meteor Network and the co-located Elginfield Infrasound Array. Each entry provides optical trajectory measurements, infrasound waveforms, and atmospheric specification profiles. The integration of optical and acoustic data enables robust linkage between observed acoustic signals and specific points along meteor trajectories, offering new opportunities to examine shock wave generation, propagation, and energy deposition processes. This release fills a critical observational gap by providing the first validated, openly accessible archive of simultaneous optical–infrasound meteor observations that supports trajectory reconstruction, acoustic propagation modeling, and energy deposition analyses. By making these data openly available in a structured format, this work establishes a durable reference resource that advances reproducibility, fosters cross-disciplinary research, and underpins future developments in meteor physics, atmospheric acoustics, and planetary defense. Full article

Daylighting plays a pivotal role in mosques, shaping their sacred atmosphere and enhancing the spiritual experience for worshippers. Beyond a mere architectural consideration, the integration of natural light into mosque design fundamentally influences the ambiance and functionality of these religious spaces. This study investigates the key factors that enhance daylight levels and visual comfort within prayer halls. It specifically evaluates illuminance levels, light distribution, and glare in four domed mosques located in Saudi Arabia. Field measurements were conducted beneath the domes of these prayer spaces, each featuring clerestory windows of varying forms and dimensions. Based on architectural specifications and material properties, daylight simulations and modeling were performed using the RADIANCE engine integrated with Grasshopper. The simulation results were validated against on-site illuminance measurements to ensure model accuracy and reliability. The primary objective was to assess whether the existing daylighting conditions comply with the recommended illuminance standards for reading and prayer, typically ranging from 150 to 500 lux. This study revealed that the illuminance levels in the central dome area exceeded the recommended values, reaching over 3000 lux. To improve daylight distribution, shading systems such as flat and curved shelves were added to the drum’s windows. This research concludes that the light shelves and vacuum double glazing significantly improved indoor daylight performance by preventing direct sunlight entry into the prayer hall and redirecting it towards the dome. This intervention successfully reduced excessive illuminance levels to a more optimal level of around 447–774 lux during the noon prayer period, ensuring a balanced and comfortable environment for worshippers. Full article