Artiles
Open Access
Article
08 May 2026Characterization and Thermal Study of Raw and Purified Pyrophyllites
Pyrophyllite is a 2:1 layered silicate with interest in ceramics, refractories, and several other important applications. In this work, an investigation into the thermal behaviour of several natural and purified pyrophyllite samples, including a pyrophyllite clay, has been conducted. A previous characterization of these samples has been carried out by AA, XRD, thermal analysis by thermo-dilatometry and DTA-TG, surface area, and SEM-EDX. Thus, relevant chemical, mineralogical, thermal, and textural data of these samples have been obtained. As a second step of this investigation, the thermal behaviour of these pyrophyllite samples has been investigated by XRD and SEM after several thermal treatments at 800, 1100 and 1150 °C during 24 h. The formation of dehydroxylated pyrophyllite as a crystalline phase in the samples was established after 1050 °C by XRD, and its permanency above this temperature, with little changes in morphological features, as revealed by SEM. When thermal treatment was progressive at higher temperatures (1300 °C) the following was evidenced by XRD: (a) the formation and crystallization of mullite (3Al2O3·2SiO2), with a progressive destruction of dehydroxylated pyrophyllite, and (b) the formation of cristobalite (SiO2). This later phase was formed by crystallization of the amorphous silica, detected as a hump by XRD, which is segregated in the solid-state reaction of formation of mullite. This treatment produces a new microstructure with elongated and needle-like crystals of mullite according to SEM observations. All these results have been found of interest for the preparation of ceramic materials, mullite-based ceramics, and refractories using these pyrophyllite samples.
Open Access
Review
08 May 2026Anthropology of Undernutrition Among Indian Tribal Adults: A Comprehensive Review
This review aimed to synthesize evidence from 2010–2024 on the nutritional status of adult tribal populations in India, with a focus on Chronic Energy Deficiency (CED) as assessed by Body Mass Index (BMI). Given the persistent health disparities among India’s Scheduled Tribes (STs), the study sought to examine geographic patterns, sex differentials, and contextual determinants of undernutrition across major tribal regions of the country. A systematic literature search was conducted using Google Scholar, PubMed, and JSTOR to identify peer-reviewed studies on adult tribal nutrition in India published between 2010 and 2024. National datasets—including the Census of India (2011) and the National Family Health Survey (NFHS-5, 2019–2021)—were used to provide demographic and health context. Eligible studies reported BMI-based nutritional assessments using the WHO (1995) BMI classification (CED defined as BMI < 18.5 kg/m2). Forty-four studies met the inclusion criteria. Extracted data were summarized by region, tribe, sex, and CED prevalence. The review reveals pronounced regional and sex-based disparities in CED among tribal adults. Northern and Northeastern tribal groups exhibited highly variable CED levels, ranging from very low in the Apatani (≤2%) to extremely high among Gujjar and Bakerwal women (90.7%). Eastern India showed consistently elevated CED, particularly among the Bhumij, Lodha, Kheria, and Santal tribes, with female CED often exceeding 50%. Central and Western tribes—including the Gonds, Kharwar, Mawasi, and Tadvi—displayed widespread undernutrition driven by food insecurity, poverty, and limited healthcare access. Southern India showed critical CED prevalence among Jenu Kuruba and Koraga adults (>90%), while island populations such as the Shompens exhibited low CED but high anaemia burdens. NFHS-5 corroborated these findings, indicating serious national-level CED prevalence among ST adults (18.4% in men, 25.5% in women). Across regions, coexisting burdens of anaemia, tuberculosis, hemoglobinopathies (e.g., sickle cell disease), leprosy, and vector-borne diseases further compounded poor nutritional status. Adult tribal populations in India experience disproportionately high levels of CED, shaped by intersecting structural and cultural determinants including poverty, geographic isolation, gender inequality, food insecurity, and limited access to health services. The wide regional variability underscores the need for targeted, culturally informed, region-specific nutritional interventions. Strengthening surveillance, improving healthcare accessibility, and promoting community-engaged, bottom-up health strategies are essential for reducing disparities and achieving national commitments to the Sustainable Development Goals, particularly the mandate to “Leave no one behind”.
Open Access
Article
08 May 2026Daily Variability of Climatic Projection Extremes Indices of Precipitation and Temperature in the Koliba-Corubal Watershed (Guinea and Guinea-Bissau)
Climate change is exacerbating extreme weather events in West Africa, threatening water resources and livelihoods. The Koliba-Corubal transboundary basin (Guinea-Guinea-Bissau), located primarily outside the Sahel region, constitutes a major freshwater resource for the area. This study analyzes the future daily variability of extreme rainfall and temperatures in this basin using CMIP6 projections. Four climate models (GFDL-ESM4, MPI-ESM1-2-HR, UKESM1-0-LL, IPSL-CM6A-LR) under the SSP1-2.6 and SSP5-8.5 scenarios were used. Six extreme precipitation indices (R99p, Rx3day, Rx5day, SDII, CWD, R20mm) and four extreme temperature indices (TN90p, TNx, TX90p, TXx) were calculated for three time horizons (2021–2050, 2051–2080, 2071–2100) and compared to the reference period 1985–2014. Extreme precipitation decreases considerably in both scenarios (under SSP1-2.6, −45.4% for R99p and −42.0% for Rx3day compared to the reference period 1985–2014), with a marked downward trend at the beginning of the period followed by an increase around 2100 under SSP5-8.5 (R99p: −37.4%; Rx3day: −20.2%). Concurrently, extreme temperatures are increasing significantly, particularly under SSP5-8.5, where TN90p is projected to increase by 169.7% by 2071–2100. Mann-Kendall tests confirm significant trends for most indices under the highest emissions scenario. The spatial distribution shows marked heterogeneity, with higher values in the central mountain areas. These results underscore the urgent need to adapt water resource management strategies and agricultural policies in this transboundary basin in the face of the projected intensification of climate extremes by the end of the century.
Open Access
Article
07 May 2026An Investment Framework for Multi-Energy Complementary System Based on the Pythagorean Fuzzy Prospect-GLDS Model
Multi-Energy Complementary Systems (MECS) are integrated energy systems that incorporate renewable energy sources such as wind and solar power, combined with energy storage and conversion technologies. They aim to enhance energy utilization efficiency and ensure supply stability through synergistic optimization. Scientific investment decision-making is crucial for the low-carbon transition of regional energy systems. However, MECS investments face challenges such as high uncertainties and the fuzziness of expert evaluations. To address this question, this paper proposes a multi-criteria decision-making (MCDM) framework integrated with fuzzy theory. An evaluation system is constructed, which includes five dimensions: resources, economy, environment, society, and infrastructure. The Choquet integral is employed to handle resource indicators, Pythagorean fuzzy sets (PFS) are introduced to process qualitative evaluations, and a combined weighting approach integrating Fuzzy Weighting with Zero-Inconsistency (FWZIC) and Weights by Envelope and Slope (WENSLO) is utilized to determine criteria weights. Finally, prospect theory is fused with the Gained and Lost Dominance Score (GLDS) method for alternative ranking. An empirical study on MECS investment in Hebei Province, China, is conducted. The results indicate that the economic dimension exerts the most significant influence, and the Chengde Weichang project demonstrates the optimal comprehensive benefits. This research provides methodological references and a practical basis for MECS investment decision-making and regional energy optimization.
Open Access
Communication
07 May 2026A Contemporary Analysis of Changing Payments for Surgical and Transcatheter Valve Procedures
We aimed to quantify contemporary changes in physician Medicare reimbursement for surgical and transcatheter valvular procedures. Publicly available 2015–2023 data from the Centers for Medicare & Medicaid Services were used to identify annual physician reimbursement fees for four procedures: surgical aortic valve replacement (SAVR), transcatheter aortic valve replacement (TAVR), mitral valve repair (MVr), and MitraClip. Physician reimbursement fees were adjusted for inflation into 2023 U.S. dollars. Changes over time were analyzed using linear regression to account for differences in average annual U.S. dollar decline, average annual percent change, and total percent change over the study period. Reimbursement for surgical and transcatheter valve procedures declined by a combined total of 28.5%: 25.8% SAVR, 34.2% TAVR, 25.8% MVr, and 28.3% MitraClip. They corresponded to average annual percent changes of −3.7% (SAVR), −5.1% (TAVR), −3.7% (MVr), and −4.1% (MitraClip)—representing a collective decline in reimbursement fee per patient of $784.96 (SAVR), $624.73 (TAVR), $823.54 (MVr), and $706.12 (MitraClip) over the nine-year study span. Over the last decade, physician reimbursement for surgical and transcatheter valve procedures has significantly decreased, potentially threatening access to quality cardiac care within the heart team approach.
Open Access
Article
07 May 2026Research on Trajectory Generation Method for Multi-Objective Optimization of Thrust Vector Vehicle in Constrained Space
Thrust-vectoring UAVs can realize decoupling of position and attitude compared with conventional quadrotors due to the ability to change thrust direction, and are used to perform various complex indoor and outdoor missions. However, existing trajectory generation frameworks are mostly for quadrotors with fixed thrust direction and a coplanar surface, and do not consider the dynamics of thrust-vectoring UAVs. To address this, this paper proposes a multi-objective trajectory generation method for thrust-vectoring UAVs in constraint space. By parametrically modeling the constraint space, the method considers the effects of environmental boundary constraints and platform dynamics characteristics on the collision constraints and motion decoupling of the trajectory, and comprehensively optimizes the trajectory’s indicators of stability, speed, and safety to plan the states and input actions of the flight trajectory. Meanwhile, a trajectory generation evaluation system is proposed, given that compared with the conventional quadratic objective function, the proposed method is effective in reducing the attitude change of the trajectory, improving the rapidity and safety, in which $$L_{\theta}$$ and $$L_{r i s k}$$ are reduced by 70.4% and 19.1%, respectively. Meanwhile, by comparing with the conventional quadrotor, the advantages of the thrust-vectoring in decoupling motion are quantified, especially in reducing the attitude change during flight, the pitch angle of the generated trajectory is reduced from ±30° to within ±20° degrees, which exerts the motion decoupling advantages of the thrust-vectoring.
Open Access
Article
06 May 2026Dispersion During Underground Hydrogen Storage in Depleted Gas Reservoirs
Dispersion in porous media is a multiscale process that governs the distribution and mixing of fluids in the subsurface. In underground hydrogen storage, dispersion is particularly critical due to hydrogen’s low molecular weight and large density contrast relative to natural gas. In addition to this, cyclic operations amplify mixing and transport effects beyond what is typically observed during conventional gas injection and storage. The apparent mixing observed during storage arises from the combined influences of localized dispersion, heterogeneity-driven channeling, and gravity segregation. Distinguishing between local, echo, and transmission dispersion provides a start for understanding reversible and irreversible components of mixing, and for connecting localized processes with field-scale performance. This study develops a systematic method to quantify dispersion in hydrogen storage within depleted gas reservoirs by combining analytical solutions of the convective–diffusive equation with multidimensional numerical simulations. The approach translates concentration fields into effective dispersion coefficients using different methods for mixing-zone length analysis. This enables evaluation across different permeability distributions, anisotropies, and spatial correlation lengths. The method is applied under both linear and radial flow conditions, including cyclic injection and production, to capture the distinct roles of gravity segregation, heterogeneity, and boundary conditions. Across the studied cases, the effective dispersion coefficient increases from approximately 1.03 to 3.5 m2/day as the Dykstra–Parsons coefficient increases from 0.3 to 0.9. Gravity segregation significantly alters plume evolution, reducing effective mixing zone lengths and introducing asymmetric displacement behavior. Under cyclic radial injection–production, incomplete plume reversal leads to persistent concentration halos, indicating irreversible mixing. The ratio of echo to transmission dispersion further quantifies the degree of irreversibility in the system. This work establishes a quantitative framework for characterizing dispersive transport in hydrogen storage systems and provides a basis for evaluating storage performance and reversibility under realistic subsurface conditions.
Open Access
Perspective
06 May 2026Eyewitness Memory: A Plea for a Detailed Study of Social Influence at Encoding
The evaluation of eyewitness memories has benefited greatly from basic memory research, which has shown that suggestive information or misinformation presented by a social source after an event can create substantial memory biases in participants’ memory, or even completely fabricated false memories. However, possible social influence occurring already at the stage of encoding (during the event) has so far been widely neglected. In basic research, meanwhile, several studies address this issue specifically with regard to incidental encoding of information (non-intentional encoding “along the way”, as it also occurs in eyewitness memories). The studies demonstrate that the social context at encoding influences how stimuli are encoded, and in one case even supports the occurrence of rich and detailed false memories. There are still many differences between the laboratory studies performed so far and any conceivable real-life scenarios of eyewitness situations. However, based on the results, it seems highly promising to evaluate the actual relevance of these initial findings for forensic science by modifying the paradigms to better reflect social encoding contexts that more closely resemble typical real-life eyewitness situations.
Open Access
Review
06 May 2026Recycling of Post-Consumer Cotton Waste
This review aims to address the environmental issues associated with the textile sector and explores innovative and optimal approaches for the zero-waste recycling of post-consumer cotton waste. The textile industry can transition toward a circular economy by implementing various recycling techniques. This will significantly cut the waste and raw material consumption, while promoting sustainability and environmental responsibility in textile manufacturing and consumption practices. This study focuses on several key techniques, including producing carbon fibres from waste, which provides a sustainable alternative to petroleum-based precursors. In addition, the regeneration of viscose fibres is achieved by chemical recycling of cotton waste and enzymatitc recycling. Method of Gasification and Thermochemical Valorisation, ioncell process is also discussed, emphasizing its potential to encourage resource conservation and lessen dependency on virgin resources. It also explains how cellulose nanofibrils (CNFs) can be extracted from post-consumer textiles and utilised to produce high-performance materials. Additionally, despite difficulties in preserving fibre quality, the potential of mechanical recycling techniques to yield viable yarns from recycled fibres is investigated.
Open Access
Communication
30 April 2026Peculiarities of Radiation Synthesis of MeWO4 Ceramics
We report the results of MeWO4 ceramics synthesis by the direct exposure of metal (Mg, Ca, Zn, W) oxides mixture to a high-power flux of high-energy electrons. The oxide powder particle sizes are 1–10 microns. The synthesis occurs with high efficiency in less than 1 s without the use of any additional substances and energy sources. The purpose of this work is to establish the main processes that ensure the effective synthesis of MgWO4, CaWO4, and ZnWO4 ceramics from ZnO, CaO, MgO, and WO4 oxides, which differ significantly in their physical and chemical properties. It has been found that the dependence of synthesis efficiency on the electron beam power density and the power density threshold at which synthesis begins varies significantly for simple metal oxides and is very close for the tungstates of these metals. The most probable explanation for the observed effect is redistribution of absorbed radiation energy. WO3 powder particles have a high absorptance of the incident electron radiation. The result is a cascade multiplication of primary electrons into secondary electrons with much lower energy. Secondary electrons are efficiently absorbed by MgO, CaO, and ZnO particles, leading to their efficient decomposition and the formation of a new phase.
