Search Results (1,974)

In this work, a quantitative analysis of Li in natural brines was carried out by laser-induced breakdown spectroscopy (LIBS) assisted by the τ–algorithm for detailed analysis of the experimental line shapes (τLIBS). Brine samples were collected from different salars located in the Puna plateau (Northwest Argentina) and analyzed by LIBS in the form of solid pressed pellets. The emission intensities of Li I, H_α, and Mg I–II lines were measured and spatially integrated along the line of sight with temporal resolution by using a high-spectral-resolution spectrometer equipped with an intensified charge-coupled device (iCCD) detector. The plasma was characterized through the determination of the electron density and the temperature. The τ–algorithm calculated the optical thicknesses of the Li I lines to generate synthetic intensity profiles that were subsequently fitted to the experimental spectra. By applying the developed τLIBS approach, valuable spectroscopic insight was recovered about the physical processes occurring in the plasma, such as self-absorption. The analytical process involved an univariate external calibration process using the resonant Li I line at 6707.7 Å measured from a series of Li standard samples. Self-absorption effects were evaluated and subsequently compensated. The final LIBS results, with an enhanced accuracy of 15%, were validated by crosschecking them against those obtained with the standard AAS method. Full article

The decarbonization of regional passenger rail transport is one of the key challenges for the sustainable transformation of the transport sector in Poland. While railway transportation remains one of the least carbon-intensive modes of transport, significant emission disparities persist between electrified and non-electrified lines, where diesel traction is still prevalent. This article presents a comparative analysis of various propulsion technologies—diesel, hybrid, battery-electric and hydrogen fuel-cell—taking into account both local (TTW) and total (WTW) greenhouse gas emissions. The study incorporates Poland’s current energy mix and proposes a methodological framework to assess emissions at the line level. It highlights the risks of focusing exclusively on in situ zero-emission technologies and calls for a more flexible, efficiency-based approach to fleet modernization. The analysis demonstrates that hybrid and optimized combustion-based systems can provide substantial emission reductions in the short term, especially in rural and transitional regions. The paper also critically discusses transport funding policies, pointing to discrepancies between incentives for private electric mobility and the lack of support for public transport solutions that could effectively counter mobility exclusion. The presented methodology and conclusions provide a basis for further research on transport decarbonization strategies tailored to national and regional contexts. Full article

Marine magnetic surveys are vast and time-consuming, and researchers have long been seeking an economical mode for large-area data acquisition. A towed magnetic measurement system was developed based on the motion characteristics of the wave glider. By modifying the SeaSPY2 magnetometer, a twin-body towed configuration was developed, in which an S-shaped towing cable mitigates motion-induced impacts from the platform, and a high-precision GNSS positioning module was integrated into the system. Sea trials were conducted in the coastal waters near Qingdao. The results indicated that the system achieved an average cruising speed of 0.56 m/s, with the towed body’s pitch and roll angles controlled within ±5° and ±1°, respectively. The dynamic noise was measured at 0.0639 nT (Level 1), and the internal consistency for repeated survey lines and cross lines was 1.832 nT and 1.956 nT, respectively, meeting the requirements of marine magnetic survey standards. The system offers unmanned operation, zero carbon emissions, and a minimal environmental footprint, and long endurance, supporting applications such as nearshore exploration, mapping in sensitive marine areas, and underwater magnetic target detection. The research provides a novel unmanned technological solution for deep-sea magnetic surveys and lays the foundation for low-cost, cluster-based operations. Full article

HD 50138 is a 6.6 mag emission-line B–type star, whose nature is still controversial. It has been thought to be a pre-main-sequence Herbig Be star and an evolved object with the B[e] phenomenon, possibly a mass-transferring binary system. However, it has mostly been studied on short timescales. We collected ∼1000 medium- and high-resolution spectra and available optical photometric data, which cover a time frame from 1981 to 2025, and extended the study from emission lines to a range of absorption lines. A few episodes of dramatic emission-line strength variations were uncovered as well as fast variations of the absorption line widths on timescales of several days. We also found a few previously unreported fadings of the star’s optical brightness seemingly associated with the Hα line profile changes. At the same time, it is still unclear whether the object is a single star or a binary system, as no regular variations of its observed parameters have been detected. Full article

In recent years, European and national policies on energy efficiency and sustainable construction have promoted a profound rethinking of building practices and strategies for upgrading the existing building stock. With the conversion of Law Decree No. 34 of 19 May 2020 (Decreto Rilancio) into Law No. 77 of 17 July 2020, and of Law Decree No. 76 of 16 July 2020 (Decreto Semplificazioni) into Law No. 120 of 11 September 2020, the tax deduction rate was increased to 110% for expenses related to specific interventions such as seismic risk reduction, energy retrofit, installation of photovoltaic systems, and charging infrastructures for electric vehicles in buildings—commonly known as the Superbonus 110%. Furthermore, the category of “building renovation,” as defined in Presidential Decree No. 380 of 6 June 2001 (art. 3, paragraph 1, letter d), was expanded with specific reference to demolition and reconstruction of existing buildings, allowing—under certain conditions—interventions that do not comply with the original footprint, façades, site layout, volumetric features, or typological characteristics. These measures were designed not only to positively affect household investment levels, thereby significantly contributing to national income growth, but also to support the broader objective of decarbonising the building sector while improving seismic safety. Within this regulatory and policy framework, instruments such as the Superbonus 110% have acted as a driving force for the diffusion of renovation projects aimed at enhancing energy performance and reducing greenhouse gas emissions, in line with the objectives of the European Green Deal and the Energy Performance of Buildings Directive (EPBD). This paper is situated within such a context and examines a real-world case of bio-based renovation admitted to fiscal incentives under the Superbonus 110%. The focus is placed on the procedural framework as well as on the technical, economic, and evaluative aspects, adopting a multidimensional perspective that combines regulatory, operational, and financial considerations. The case study concerns the demolition and reconstruction of a single-family residential chalet, designed according to near-Zero-Energy Building (nZEB) standards, located in the municipality of San Roberto, in the province of Reggio Calabria. The intervention is set within an environmentally and culturally sensitive area, being situated in the Aspromonte National Park and subject to landscape protection restrictions under Article 142 of Legislative Decree No. 42/2004. The aim of the study is to highlight, through the analysis of this case, both the opportunities and the challenges of applying the Superbonus 110% in protected contexts. By doing so, it seeks to contribute to the scientific debate on the interplay between incentive-based regulations, energy sustainability, and landscape–environmental protection requirements, while providing insights for academics, practitioners, and policymakers engaged in the ecological transition of the construction sector. Full article

With the rapid increase in global trade in recent years, the demand for maritime transportation has significantly intensified vessel activity, leading to a considerable rise in carbon emissions originating from the maritime sector. As a result, in line with the 2050 decarbonization targets set by the International Maritime Organization (IMO) and the European Union (EU), legal regulations addressing carbon emissions have been dynamically tightened and gradually enacted. This study aims to determine the significance levels of the factors affecting the maritime sector in response to carbon emission regulations and to reveal the interrelationships among these factors. In this context, the criteria regarding the impacts of climate-related carbon emission regulations were identified based on expert opinions using the Fuzzy Delphi method. The interaction strengths and significance levels among the factors were analyzed using the Fuzzy DEMATEL method, and the relationships were modeled through Interpretive Structural Modeling (ISM). According to the findings, “Fuel Preferences and Alternative Fuel Usage” (C2) emerged as the most critical factor under recent international regulations. “Adaptation to International and National Regulations” (C8) and “Port Infrastructure” (C3) were also identified as the key factors impacting shipping industry efficiency. The analysis revealed that “Logistics Costs” (C5) and “Environmental Protection and Sustainability” (C7) are the most significantly affected outcome factors within the system. The hierarchical structural modeling revealed that “Port Infrastructure” (C3) serves as a defining starting point within the system. This study contributes to the literature by uncovering the causal relationships among the factors determining the effectiveness of ever-evolving carbon emission regulations. It offers a valuable decision-support tool for maritime companies and policymakers. Accordingly, it provides an alternative roadmap and a structural model indicating which strategic areas should be prioritized to achieve the targeted low-carbon emission goals in maritime transportation. Full article

Theoretical foundations are presented for the application of information–entropy methods from statistical physics to the determination of stellar evolutionary stages. A balance equation involving normalized conditional information and entropy is proposed. The conditional information is defined as the difference between the entropy of the phase space and the conditional probability entropy. A correspondence is demonstrated between theoretical predictions and observational data from stellar emission spectra with respect to their evolutionary classification. The proposed methodology is further applied to the analysis of complex FS CMa-type objects, which exhibit dusty and gaseous structures with components at different evolutionary stages. In this context, the conditional information derived from asymmetric spectral lines is shown to be consistent with the theoretical criteria for the evolutionary status of single, binary, and unclassified stars. Full article

The pre-main-sequence evolution of the chemically peculiar (CP) stars on the upper main sequence is still a vast mystery and not well understood. Our analysis of young associations and open clusters aims to find (very) young CP stars to try to put a lower boundary on the age of such objects. Using three catalogues of open clusters and associations, we determined membership probabilities using HDBSCAN. The hot stars from this selection were submitted to synthetic $\Delta a$ photometry, spectral, and light curve classification to determine which ones are CP stars and candidates. Subsequently, we used spectral energy distribution fitting and emission line analysis to check for possible PMS CP stars. The results were compared to the literature. We detected 971 CP stars and candidates in 217 clusters and associations. A relatively large fraction, ∼10% of those, show characteristics of PMS CP stars. This significantly expands the known list of candidate PMS CP stars, bringing us closer to solving the mystery of their origin. Full article

In line with EU decarbonization targets for the heavy-duty transport sector, this study proposes an analytical methodology to assess the impact of diesel performance additives on fuel consumption in Euro 6 heavy-duty vehicles, the prevailing standard in the circulating European road tractor fleet. A fleet of five N3-category road tractors equipped with tanker semi-trailers was monitored over two phases. During the first 10-month baseline phase, the vehicles operated with standard EN 590 diesel (containing 6–7% FAME); in the second phase, they used a commercially available premium diesel containing performance-enhancing additives. Fuel consumption and route data were collected using a GPS-based system interfaced with the engine control unit via the OBD port and integrated with the fleet tracking platform. After applying data filtering to exclude low-quality or non-representative trips, a 1% reduction in fuel consumption was observed with the use of fuel with additives. Route-level analysis revealed higher savings (up to 5.1%) in high-load operating conditions, while most trips showed improvements between −1.6% and −3.4%. Temporal analysis confirmed the general trend across varying vehicle usage patterns. Aggregated fleet-level data proved to be the most robust approach to mitigate statistical variability. To evaluate the potential impact at scale, a European scenario was developed: a 1% reduction in fuel consumption across the 6.75 million heavy-duty vehicles in the EU could yield annual savings of 2 billion liters of diesel and avoid approximately 6 million tons of CO₂ emissions. Even partial adoption could lead to meaningful environmental benefits. Alongside emissions reductions, fuel additives also offer economic value by lowering operating costs, improving engine efficiency, and reducing maintenance needs. Full article

Background: Denture stomatitis (DS) represents an oral fungal infection induced by Candida albicans, impacting approximately 70% of the individuals who use removable acrylic dentures. Researchers suggest that the high level of the Candida species, particularly Candida albicans (C. albicans), is the predominant etiological factor of DS. Consequently, the development of a soft liner with antifungal activity might significantly enhance its therapeutic applicability. This in vitro study evaluates the impact of phosphate bioactive glass reinforced heat-cured acrylic-based soft liner on the candidal activity in this material. Method: Specimens (10 mm × 2 mm disc-like) were required for the selected test; PBG-Sr nano-powder was synthesized and added to the soft liner at percentages of 1 wt.%, 3 wt.%, 5 wt.%, and 7 wt.%. The candidal adherence test was investigated, and characterization was performed by X-ray diffraction analysis, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy mapping, and particle size analysis. The resulting data were analyzed with one-way ANOVA followed by Dunnett’s test. Results: Candidal adherence in the 1 wt.%, 3 wt.%, 5 wt.%, and 7 wt.% PBG-Sr subgroups had decreased values in comparison to the control (0 wt.%), with the 7 wt.% subgroup demonstrating the lowest count of C. albicans (0.027), close to the nystatin group. Conclusions: PBG-Sr can diminish C. albicans adhesion in soft lining materials, and a soft liner containing PBG-Sr (7 wt.%) showed the most effective activity against C. albicans in the soft liner. Soft liners infused with bioactive glass may have the potential to assist those struggling with denture stomatitis, providing patients with enhanced therapeutic qualities. Full article

Sustainable production also involves analyzing greenhouse gas (GHG) emissions throughout the entire cultivation and processing cycle. The emissions balance for different sugar beet varieties is a key element of environmental assessment in sustainable production systems. It is consistent with the objectives of the European Green Deal and aims to decarbonize agri-food technology. This study aims to assess and compare GHG emissions associated with the cultivation of three sugar beet variants (Viola, Jaromir, and Pulitzer) taking into account their technological and quality characteristics. The varieties were selected based on their registration in the National Register and their importance in agricultural practice in Poland, as well as their contrasting technological profiles, which allow for the assessment of the relationship between raw material quality and GHG balance. The study combines life cycle assessment (LCA) with physiological parameters such as CO₂ assimilation, sugar content, yield, fuel consumption, and fertilizer use. The aim is to identify the correlation between the technological value of a variety and its environmental impact. It has been shown that genotypic characteristics have a significant impact on both yield and emissions. The Viola and Jaromir varieties showed a favorable balance between photosynthetic efficiency and greenhouse gas emissions, while the Pulitzer variety, despite low emissions per kilogram of product, showed poorer yield performance. The importance of using integrated assessment methods combining production efficiency, environmental efficiency, and crop quality was emphasized. Such an approach is essential for the development of sustainable agricultural practices in line with the EU’s climate neutrality goals. Further research is needed to optimize agrotechnical strategies tailored to the requirements of individual varieties, contributing to climate-resilient and environmentally friendly crop production. Full article

The shipping industry remains heavily dependent on heavy fuel oils, which account for approximately 77% of fuel consumption and contribute significantly to greenhouse gas (GHG) emissions. In line with the IMO’s decarbonization targets, ammonia has emerged as a promising carbon-free alternative. This study evaluates the strategic viability of ammonia, especially green production, as a marine fuel through a hybrid SWOT–Best–Worst Method (BWM) analysis, combining literature insights with expert judgment. Data were collected from 17 maritime professionals with an average of 15.7 years of experience, ensuring robust sectoral representation and methodological consistency. The results highlight that opportunities hold the greatest weight (0.352), particularly the criteria “mandatory carbon-free by 2050” (O3:0.106) and “ammonia–hydrogen climate solution” (O2:0.080). Weaknesses rank second (0.270), with “higher toxicity than other marine fuels” (W5:0.077) as the most critical concern. Strengths (0.242) underscore ammonia’s advantage as a “carbon-free and sulfur-free fuel” (S1:0.078), while threats (0.137) remain less influential, though “costly green ammonia” (T3:0.035) and “uncertainty of green ammonia” (T1:0.034) present notable risks. Overall, the analysis suggests that regulatory imperatives and environmental benefits outweigh safety, technical, and economic challenges. Ammonia demonstrates strong potential to serve as viable marine fuel in achieving the maritime sector’s long-term decarbonization goals. Full article

Accurate determination of opacity is critical for understanding radiation transport in both astrophysical and laboratory plasmas. We employ atomic data from R-Matrix calculations to investigate radiative properties in high-energy-density (HED) plasma sources, focusing on opacity variations under extreme plasma conditions. Specifically, we analyze environments such as the base of the convective zone (BCZ) of the Sun ($2\times {10}^6$ K, $N_e={10}^{23}$/cc), and radiative opacity data collected using the inertial confinement fusion (ICF) devices at the Sandia Z facility ($2.11\times {10}^6$ K, $N_e=3.16\times {10}^{22}$/cc) and the Lawrence Livermore National Laboratory National Ignition Facility. We calculate Rosseland Mean Opacities (RMO) within a range of temperatures and densities and analyze how they vary under different plasma conditions. A significant factor influencing opacity in these environments is line and resonance broadening due to plasma effects. Both radiative and collisional broadening modify line shapes, impacting the absorption and emission profiles that determine the RMO. In this study, we specifically focus on electron collisional and Stark ion microfield broadening effects, which play a dominant role in HED plasmas. We assume a Lorentzian profile factor to model combined broadening and investigate its impact on spectral line shapes, resonance behavior, and overall opacity values. Our results are relevant to astrophysical models, particularly in the context of the solar opacity problem, and provide insights into discrepancies between theoretical calculations and experimental measurements. In addition, we investigate the equation-of-state (EOS) and its impact on opacities. In particular, we examine the “chemical picture” Mihalas–Hummer–Däppen EOS with respect to level populations of excited levels included in the extensive R-matrix calculations. This study should contribute to improving opacity models of HED sources such as stellar interiors and laboratory plasma experiments. Full article

The anti-correlation between the equivalent width of the neutral narrow Fe K$\alpha$ line and the 2–10 keV luminosity (the Iwasawa–Taniguchi effect) in the nuclear regions of active galactic nuclei has been debated in recent years. With the high angular resolution of Chandra, an increasing number of Compton-thick sources have been found to show extended narrow Fe K$\alpha$ emission on scales from tens of parsecs to kiloparsecs, attributed to reprocessing of nuclear radiation by surrounding Compton-thick material. We analyze eight Compton-thick sources with prominent extended Fe K$\alpha$ emission. We confirm the Iwasawa–Taniguchi effect in the extended component relative to the reflection spectrum, with a steeper slope, indicating reduced production efficiency of neutral Fe K$\alpha$ photon outside the nucleus. Both the reflection spectrum and Fe K$\alpha$ luminosities correlate positively with intrinsic AGN luminosity, suggesting that the nucleus drives the extended emission. Finally, we find a linear relationship between redshift and the equivalent width of the nuclear Fe K$\alpha$ line, with no such trend in the extended component. Full article

Offshore wind energy is rapidly expanding as a critical resource for global carbon neutrality, with 10.8 GW of new capacity added in 2023, raising the worldwide total to 75.2 GW. However, large-scale integration of offshore wind farms introduces power quality challenges due to the characteristics of inverter-based resources, particularly harmonic distortion, which can threaten system stability. This study quantitatively investigates the influence of short circuit ratio (SCR) on voltage and current harmonic distortion during offshore wind farm integration. A 500 MW offshore wind farm was modeled, and MATLAB/Simulink simulations were performed for 345 kV and 154 kV systems to evaluate the impact of varying SCR on total harmonic distortion (THD) and individual harmonic orders. Furthermore, the harmonic assessment based on the IEC 61400-21-2 summation method was compared with the simulation results, demonstrating the limitations of the simple summation approach and underscoring the importance of simulation-based evaluation. The results reveal that, under certain SCR conditions, parallel resonance caused by system impedance and line parameters produces unexpectedly high distortion in the 345 kV system, contrary to expectations based solely on voltage level. This resonance phenomenon and SCR dependency were also validated using short circuit capacity data from actual offshore wind farm candidate sites. Overall, the study emphasizes the necessity of comprehensive power quality assessments that account for SCR conditions, voltage levels, and harmonic emission characteristics, providing practical guidance for site selection, substation design, and harmonic mitigation in offshore wind integration. Full article