Search Results (254)

Filled pauses are thought to be reflections of linguistic processes (e.g., lexical retrieval, speech planning and execution). Uh may be a self-directed cue for when a speaker needs more time to retrieve lexical–semantic representations, whereas um serves as a listener-directed, pragmatic cue. The use of filled pauses has not been examined in children who are hard of hearing (CHH). Participants included 68 CHH and 33 children with typical hearing (CTH). Participants engaged in conversations, expository discourse, and fable retells. We analyzed filled pauses as a function of hearing status and discourse contexts and evaluated the relationship between filled pauses and language ability. CHH produced uh across discourse contexts more often than their hearing peers. CHH did not differ in their use of um relative to CTH. Both um and uh were used more often in conversational samples compared to other types of discourse. Spearman’s correlations did not show any significant associations between the rate of filled pauses and standardized language scores. These results indicate that CHH produces uh more often than CTH, suggesting that they may have difficulty retrieving lexical–semantic items during ongoing speech. This information may be useful for interventionists who are collecting language samples during assessment. Full article

Underground hydrogen storage (UHS) in geological formations offers a promising solution for large-scale energy buffering, but its long-term safety and mechanical stability remain concerns, particularly in fractured rock environments. This study develops a fully coupled thermo-mechanical model to investigate the cyclic response of a dual-cavern hydrogen storage system with polymer-based sealing layers. The model incorporates non-isothermal gas behavior, rock heterogeneity via a Weibull distribution, and fracture networks represented through stochastic geometry. Two operational scenarios, single-cavern and dual-cavern cycling, are simulated to evaluate stress evolution, displacement, and inter-cavity interaction under repeated pressurization. Results reveal that simultaneous operation of adjacent caverns amplifies tensile and compressive stress concentrations, especially in inter-cavity rock bridges (i.e., the intact rock zones separating adjacent caverns) and fracture-dense zones. Polymer sealing layers remain under compressive stress but exhibit increased residual deformation under cyclic loading. Contour analyses further show that fracture orientation and spatial distribution significantly influence stress redistribution and deformation localization. The findings highlight the importance of considering thermo-mechanical coupling and rock fracture mechanics in the design and operation of multicavity UHS systems. This modeling framework provides a robust tool for evaluating storage performance and informing safe deployment in complex geological environments. Full article

Underground hydrogen storage (UHS) in carbonate and siliceous formations presents a promising solution for managing intermittent renewable energy. However, experimental data on hydrogen–rock interactions under representative subsurface conditions remain limited. This study systematically investigates mineralogical and petrophysical alterations in dolomite, calcite-rich limestone, and quartz-dominant siliceous cores subjected to high-pressure hydrogen (100 bar, 70 °C, 100 days). Distinct from prior research focused on diffraction peak shifts, our analysis prioritizes quantitative changes in mineral concentration (%) as a direct metric of reactivity and structural integrity, offering more robust insights into long-term storage viability. Hydrogen exposure induced significant dolomite dissolution, evidenced by reduced crystalline content (from 12.20% to 10.53%) and accessory phase loss, indicative of partial decarbonation and ankerite-like formation via cation exchange. Conversely, limestone exhibited more pronounced carbonate reduction (vaterite from 6.05% to 4.82% and calcite from 2.35% to 0%), signaling high reactivity, mineral instability, and potential pore clogging from secondary precipitation. In contrast, quartz-rich cores demonstrated exceptional chemical inertness, maintaining consistent mineral concentrations. Furthermore, Brunauer–Emmett–Teller (BET) surface area and Barrett–Joyner–Halenda (BJH) pore distribution analyses revealed enhanced porosity and permeability in dolomite (pore volume increased >10×), while calcite showed declining properties and quartz showed negligible changes. SEM-EDS supported these trends, detailing Fe migration and textural evolution in dolomite, microfissuring in calcite, and structural preservation in quartz. This research establishes a unique experimental framework for understanding hydrogen–rock interactions under reservoir-relevant conditions. It provides crucial insights into mineralogical compatibility and structural resilience for UHS, identifying dolomite as a highly promising host and highlighting calcitic rocks’ limitations for long-term hydrogen containment. Full article

Heart failure (HF) is a complex clinical syndrome that results from any structural or functional impairment of ventricular filling or ejection of blood. The etiology of heart failure is multifactorial, encompassing ischemic heart disease, hypertension, valvular disorders, cardiomyopathies, and metabolic and infiltrative diseases. Despite advances in pharmacologic and device-based therapies, heart failure continues to carry a substantial burden of morbidity, mortality, and healthcare utilization. With the advancement and increased accessibility of cardiac imaging modalities, the diagnostic accuracy for identifying the underlying etiologies of nonischemic cardiomyopathy has significantly improved, allowing for more precise classification and tailored management strategies. This review aims to provide a comprehensive analysis of the current understanding of heart failure, encompassing epidemiology, etiological factors, with a specific focus on diagnostic imaging modalities including the role of echocardiography and strain imaging, cardiac magnetic resonance imaging (CMR), cardiac computed tomography (CT), and nuclear positron emission tomography (PET) imaging and recent advances in the diagnosis and management of heart failure. Full article

The global energy sector is aiming to substantially reduce CO₂ emissions to meet the UN climate goals. Among the proposed strategies, underground storage solutions such as radioactive disposal, CO₂, NH₃, and underground H₂ storage (UHS) have emerged as promising options for mitigating anthropogenic emissions. These approaches require rigorous research and development (R&D), often involving laboratory-scale experiments to establish their feasibility before being scaled up to pilot plant operations. Microorganisms, which are ubiquitous in laboratory environments, can significantly influence geochemical reactions under variable experimental conditions of porous media and a salt cavern. We have selected a consortium composed of Bacillus sp., Enterobacter sp., and Cronobacter sp. bacteria, which are typically present in the laboratory environment. These microorganisms can contaminate the rock sample and develop experimental artifacts in UHS experiments. Hence, it is pivotal to sterilize the rock prior to conduct experimental research related to effects of microorganisms in the porous media and the salt cavern for the investigation of UHS. This study investigated the efficacy of various disinfection and sterilization methods, including ultraviolet irradiation, autoclaving, oven heating, ethanol treatments, and gamma irradiation, in removing the microorganisms from silica sand. Additionally, the consideration of their effects on mineral properties are reviewed. A total of 567 vials, each filled with 9 mL of acid-producing bacteria (APB) media were used to test killing efficacy of the cleaning methods. We conducted serial dilutions up to 10⁻⁸ and repeated them three times to determine whether any deviation occurred. Our findings revealed that gamma irradiation and autoclaving were the most effective techniques for eradicating microbial contaminants, achieving sterilization without significantly altering the mineral characteristics. These findings underscore the necessity of robust cleaning protocols in hydrogeochemical research to ensure reliable, reproducible data, particularly in future studies where microbial contamination could induce artifacts in laboratory research. Full article

In this study, we show how uniform hazard spectra (UHS) can contribute to sustainable development in regions with frequent moderate to strong seismic events and a variety of deeper geological conditions, by reducing seismic risks and enhancing resilience. The case study region surrounds a site at Banja Luka, Bosnia and Herzegovina. Frequency-dependent scaling equations are presented. UHS spectra for Banja Luka are calculated utilizing regional seismicity estimations, deep geology data, and the regional empirical formulae for scaling different PSA amplitudes. The UHS amplitudes are compared with Eurocode 8 spectra. The results demonstrate that the ratios of the highest UHS amplitudes to the corresponding PGA values differ significantly from 2.5, which is the factor specified by Eurocode 8 for the horizontal ground motion. The results also suggest that the influence of deep geology on UHS amplitudes can outweigh local soil effects. For example, at the vibration period of 0.1 s, the largest site effects are obtained for deep geology when comparing the UHS amplitude at geological rock to that at intermediate sites. In this case, the deep geology amplification of 1.47 is 19% higher than the local soil amplification of 1.24 for the same vibration period at the stiff soil sites compared to the rock soil sites. The UHS obtained may be interpreted as preliminary for Banja Luka and other places with similar deep geology, local soil conditions, and seismicity. When the quantity of strong-motion data in the region increases significantly beyond what it is now, it will be possible to correctly calibrate the existing attenuation equations and obtain more reliable UHS estimates. Full article

The transition to a sustainable energy future hinges on the development of reliable large-scale hydrogen storage solutions to balance the intermittency of renewable energy and decarbonize hard-to-abate industries. Underground hydrogen storage (UHS) in salt caverns emerged as a technically and economically viable strategy, leveraging the unique geomechanical properties of salt formations—including low permeability, self-healing capabilities, and chemical inertness—to ensure safe and high-purity hydrogen storage under cyclic loading conditions. This review provides a comprehensive analysis of the advantages of salt cavern hydrogen storage, such as rapid injection and extraction capabilities, cost-effectiveness compared to other storage methods (e.g., hydrogen storage in depleted oil and gas reservoirs, aquifers, and aboveground tanks), and minimal environmental impact. It also addresses critical challenges, including hydrogen embrittlement, microbial activity, and regulatory fragmentation. Through global case studies, best operational practices for risk mitigation in real-world applications are highlighted, such as adaptive solution mining techniques and microbial monitoring. Focusing on China’s regional potential, this study evaluates the hydrogen storage feasibility of stratified salt areas such as Jiangsu Jintan, Hubei Yunying, and Henan Pingdingshan. By integrating technological innovation, policy coordination, and cross-sector collaboration, salt cavern hydrogen storage is poised to play a pivotal role in realizing a resilient hydrogen economy, bridging the gap between renewable energy production and industrial decarbonization. Full article

Uncomplicated hypertension (UH) during pregnancy represents a common condition, worsening maternal and fetal prognosis. However, no single biomarker has proven optimal for determining the risk of UH. We developed an early risk multivariate model for UH, integrating hemodynamics with biochemistry, focusing on the relationship between blood pressure (BP) indices, uric acid (UA), and angiogenesis-related factors (AF). We collected and analyzed data on 24 h ambulatory BP monitoring, demographic, epidemiological, clinical, and laboratory variables from 132 pregnancies. The main predictors were BP indices and serum UA and AF levels. Uncomplicated hypertension, defined as the presence of gestational hypertension or worsening of essential hypertension beyond the 20th week, was the main outcome. The combined second-degree polynomial transformation of UA and the AF (sFlt-1/PIGF) ratio, called the UA-AF Index, consistently showed a positive association with UH. The models incorporating nighttime BP indices combined with the UA-AF Index outperformed the others, with the best-performing model based on the nocturnal systolic BP (SBP). Specifically, in the best-fitting model (nighttime SBP + UA-AF Index as predictors), each 1 mmHg increase in nocturnal SBP was associated with a 10% higher risk of UH, while each one-unit increase in the UA-AF Index raised the likelihood of UH by more than twofold (accuracy: 0.830, AUC 0. 874, SE 0.032, p-value < 0.001, 95%CI 0.811–0.938). The combination of nighttime blood pressure indices, serum uric acid, and angiogenesis-related factors may provide added value in the assessment of uncomplicated hypertension during pregnancy. Full article

In this work, we address a nonlinear $\psi$-Hilfer fractional-order Volterra integro-differential equation that incorporates n-multiple-variable time delays. Employing the $\psi$-Hilfer fractional derivative operator, we investigate the existence of a unique solution, as well as the Ulam–Hyers–Rassias stability, semi-Ulam–Hyers–Rassias stability, and Ulam–Hyers stability of the proposed $\psi$-Hilfer fractional-order Volterra integro-differential equation through the fixed-point approach. In this study, we enhance and generalize existing results in the literature on $\psi$-Hilfer fractional-order Volterra integro-differential equations, both including and excluding single delay, by establishing new findings for nonlinear $\psi$-Hilfer fractional-order Volterra integro-differential equations involving n-multiple-variable time delays. This study provides novel theoretical insights that deepen the qualitative understanding of fractional calculus. Full article

Morocco, like many nations undergoing significant economic and social transformation, is experiencing rapid urbanization alongside an ongoing rural exodus. This, coupled with the country’s diverse climate and heterogeneous geography, warrants a detailed exploration of urbanization’s effect on surface climate. Utilizing the Simple Biosphere (SiB2) model’s simulated surface temperature, this study analyses summer’s urban heat structure of seven Moroccan urban areas and their surroundings, assessing the urban impact on surface temperature at the city center, and the intensity and spatial distribution of the urban heat island (UHI) effect at different spatial resolutions. Results show wide-ranging dissimilarities in urban thermal profiles, with the maximum UHI intensity recorded at 8.7 °C in the Dakhla peninsula. Urban heat sink (UHS) effects were observed in six of the seven studied cities, with Marrakech being the exception, only exhibiting UHI effects. A more detailed examination of the thermal profile in Rabat’s metropole at a finer scale, using Landsat-observed land surface temperature (LST), yields additional insights into UHI characteristics, and the findings are contrasted with the existing literature to provide broader insights. The implications of this study strongly resonate within the Moroccan context and its neighboring regions with similar environmental and socio-economic features and should aid in the development of sustainable regional urban planning. Full article

Background/Objectives: In this retrospective study, we aimed to compare the efficacy, survival, and toxicity results of induction (IC) or adjuvant (AC) treatment with chemoradiotherapy (CRT) in locally advanced nasopharyngeal cancer (NPC). Methods: A total of 405 patients from 22 different centres in Turkey, belonging to the Turkish Oncology Group (TOG), was included. The primary endpoints were overall survival (OS) and progression-free survival (PFS), and the secondary endpoints were safety and toxicity. Results: The median age of the patients included in the study was 49 (18.2–91.5) years. In total, 298 (73.6%) of the patients were male. Of the 405 patients, 258 (63.7%) received IC and 147 (36.3%) received AC treatment. When OS and PFS analyses were performed in terms of age, gender, T and N stages, pathological features, and treatments received, no effect of any variable on prognosis was observed. For the overall group, the median estimated OS was 137.3 months (the Kaplan–Meier statistical method could not reach the 95% confidence interval [CI]). For the IC group, the median estimated survival was 137.3 months (95% CI: 111.4–163.3), whereas the Kaplan–Meier statistical method could not estimate survival for the AC group. No statistically significant difference was observed between IC and AC groups in terms of OS (p = 0.209) or PFS (p = 0.248). Grade 3–4 side effects were observed in 12% of patients in the IC group and 29.9% of patients in the AC group. Treatment was discontinued due to toxicity in 5 patients (1.9%) in the IC group and 18 patients (12.2%) in the AC group. Conclusion: No difference in OS or PFS was observed between AC and IC treatments. More grade 3–4 side effects were observed in the AC-treated group and early discontinuation rate was higher. Full article

In recent years, underground hydrogen storage (UHS) has become a hot topic in the field of deep energy storage. Green hydrogen, produced using surplus electricity during peak production, can be injected and stored in underground reservoirs and extracted during periods of high demand. A profound understanding of the mechanisms of the gas–water two-phase flow at the pore scale is of great significance for evaluating the sealing integrity of UHS reservoirs and optimizing injection, as well as the storage space. The pore structure of rocks, as the storage space and flow channels for fluids, has a significant impact on fluid injection, production, and storage processes. This paper systematically summarizes the methods for characterizing the micro-pore structure of reservoir rocks. The applicability of different techniques was evaluated and compared. A detailed comparative analysis was made of the advantages and disadvantages of various numerical simulation methods in tracking two-phase flow interfaces, along with an assessment of their suitability. Subsequently, the microscopic visualization seepage experimental techniques, including microfluidics, NMR-based, and CT scanning-based methods, were reviewed and discussed in terms of the microscopic dynamic mechanisms of complex fluid transport behaviors. Due to the high resolution, non-contact, and non-destructive, as well as the scalable in situ high-temperature and high-pressure experimental conditions, CT scanning-based visualization technology has received increasing attention. The research presented in this paper can provide theoretical guidance for further understanding the characterization of the micro-pore structure of reservoir rocks and the mechanisms of two-phase flow at the pore scale. Full article

This article presents the development and implementation of an automated digital test bench for fault diagnosis in the caution and warning panels of the UH-60 helicopter, using practices based on NASA’s systems engineering process. The research addresses the critical need to improve efficiency and accuracy in aeronautical maintenance by automating processes traditionally relying on manual techniques. Throughout the study, advanced software engineering methodologies were implemented to develop a system that significantly reduces diagnostic times and enhances the accuracy and reliability of results by integrating digital signal processing. The article highlights the economic benefits, demonstrating a substantial reduction in repair costs, and emphasizes the system’s flexibility to adapt to other aeronautical components, establishing a solid foundation for future technological innovations in aircraft maintenance. The novelty of this paper lies in integrating real-time simulation with a closed-loop diagnostic system designed primarily for the UH-60 avionics panels. This approach has not previously been applied to this series of aircraft or aeronautical components, allowing for adaptive and automated fault detection and significant improvement in diagnostic accuracy and speed in unscheduled aeronautical maintenance environments. Full article

The main goal of this study was to determine the associations between the quality of presentation of GM, motor development, and brain integrity as seen through magnetic resonance imaging. Methods: This is an observational, descriptive, and association study; information derived from it was used to analyze associations between the following variables: Writhing Movements, Fidgety Movements, motor development, and brain integrity. With a confidence level of 95% and an estimation error of 5%, the sample was comprised of 60 children under 5 months old with any neurological risk criteria; these children were either hospitalized in the Neonatal Intensive Care Unit (NICU) or attending the Kangaroo Mother Care Program (KMCP) at the University Hospital of La Samaritana (UHS), Colombia. The data were analyzed using Fisher’s exact test. Results: Over 90% of children with Absent or Sporadic Fidgety Movements had either abnormal or suspicious motor development. We observed a trend of association between the absence of Fidget Movements and alterations in White Matter. Conclusions: Quality of presentation of General Movements is associated with motor development and alterations of brain tissue at an early age, primarily in the White Matter; it is important for early prediction of neurological risk in infants. Full article

Fractional multi-delay differential systems, as an important mathematical model, can effectively describe viscoelastic materials and non-local delay responses in ecosystem population dynamics. It has a wide and profound application background in interdisciplinary fields such as physics, biomedicine, and intelligent control. Through literature review and classification, it is evident that for the fractional multi-delay differential system, the existence and uniqueness of the solution and Ulam-Hyers stability (UHS), Ulam-Hyers-Rassias stability (UHRS) of the fractional multi-delay differential system are rarely studied by using the multi-delayed perturbation of two parameter Mittag-Leffler typematrix function. In this paper, we first establish the existence and uniqueness of the solution for the Riemann-Liouville fractional multi-delay differential system on finite intervals using the Banach and Schauder fixed point theorems. Second, we demonstrate the existence and uniqueness of the solution for the system on the unbounded intervals in the weighted function space. Furthermore, we investigate UHS and UHRS for the nonlinear fractional multi-delay differential system in unbounded intervals. Finally, numerical examples are provided to validate the key theoretical results. Full article