Processes Shaping Research Articles

Surface integrity analysis of Niobium based-cermet processed by electrochemical machining and hybrid laser- electrochemical machining

Abstract This study investigates the evolution of surface integrity of a strategically important Niobium based-cermet with nickel binder (NbC-Ni), while processing it with electrochemical machining (ECM) and hybrid laser-ECM (LECM) processes for shaping towards moulds and cutting tools applications. The results indicate that, while the ECM process can preserve material properties due to its athermal and non-contact nature, it suffers from selective phase dissolution, particle breakout and passivation issues when processing the cermet. LECM synergistically applies laser and EC process energies to address these challenges, particularly by homogenizing multiphase dissolution and facilitating passivation weakening while using pH-neutral aqueous electrolyte. A combination of metallography techniques were employed to study the surface integrity and correlate it with process mechanisms. Results indicate that ECM selectively dissolves the Ni phase and induces passivation, while LECM mitigates these surface integrity compromising effects by virtue of passivation weakening (lowest O wt.% of 33.2) through enhanced transpassive dissolution and escalated reaction kinetics, leading to surface integrity improvement by lowering the roughness (Sa) by 30%, feature slopes (Sdq) by 32% and increasing the hardness (HV5 738.7) by 55% as compared to ECM. Thus LECM presents a promising technique for shaping advanced passivating and multiphase materials.

Climatic and tectonic controls on ferroan dolomite formation – insights on Early Miocene Mediterranean anoxia (il-Blata, Malta)

Records from the Miocene il-Blata section in Malta offer insights into the Central Mediterranean's depositional environments following an Early Miocene restriction of the Mesopotamian Seaway (∼20 Ma). Inorganic and organic stable carbon isotope values suggest relatively steady depositional environments, whereas authigenic Fe-dolomite abundances exhibiting substantial δ 18 O and δ 13 C variations at a sequence-scale indicate dynamic sedimentation conditions leading to differential diagenesis. Petrographically, the dolomitic levels exhibit matrix-selective dolomitisation, occasional silicification and phosphatisation, and textural indicators pointing to subsurface microbial influence which collectively point to complex shallow burial diagenesis. In addition, the presence of framboidal pyrite and gypsum infilling foraminiferal chambers along with the absence of large planktonic foraminifera, suggests the development of paleoenvironmental stress imposed by a density-stratified water column affecting pore waters. Towards the top of the studied succession, a shift from organic to siliceous deposits reflects water column perturbations possibly linked to changes in oceanic circulation associated with a temporary re-opening of the Mesopotamian Seaway. This study not only underscores hydrochemical controls exerted by North African terrigenous fluxes over the Mediterranean, but also highlights the intricate interplay between shifting depositional environments and shallow burial diagenetic processes in shaping the geochemical and textural fabrics of authigenic mineral assemblages.

Integrating Motivation Theory into the AIED Curriculum for Technical Education: Examining the Impact on Learning Outcomes and the Moderating Role of Computer Self-Efficacy

The integration of artificial intelligence (AI) technologies into education has gained increasing attention, yet limited research examines how the curriculum design can enhance learning outcomes and influence learners’ intentions to continue AI learning. This study addresses this gap by integrating the theory of planned behavior, technology acceptance model, theories of motivation, and computer self-efficacy to explore the factors affecting learners’ behavioral intentions in AI education. Using the AI course quality as the primary antecedent and “intention to continue taking courses” as the dependent variable, the study investigates the structural relationships and mediating variables between these factors. Data were collected through a stratified random sampling method from 19 universities in Taiwan, involving 200 students who had completed five core AI-related courses, including artificial intelligence, machine learning, internet of things, big data, and robotics. The analysis, conducted using PLS-SEM, revealed that AI course quality directly and indirectly influences learners’ behavioral intentions through mediating variables such as learning satisfaction, computer self-efficacy, technological literacy, and computer learning motivation. Moreover, AI course quality exerted a significant positive effect on computer motivation, which, in turn, influenced self-efficacy and learning outcomes. These findings provide valuable insights into the antecedents and processes shaping learners’ intentions to continue AI learning, offering practical and theoretical implications for AI education.

Impacts of model resolution on the simulation of sea-level variability by a global ocean-sea ice model

The effects of model resolution on the simulation of sea-level variability were analyzed based on the second-generation climate system ocean model from the State Key Laboratory of Numerical Modeling for Atmospheric Science and Geophysical Fluid Dynamics, Institute of Atmosphere Physics (LICOM2) with resolutions of 1° (LICOM2-L) and 0.1° (LICOM2-H).The interannual variability, decadal variability, and long-term trends of the dynamic sea level (DSL) are estimated using a multivariate linear regression model based on the LICOM2-L and LICOM2-H datasets during 1958–2007. The analysis reveals that the distributions of interannual and decadal variability, as well as long-term trends, are consistent between the LICOM2-L and LICOM2-H simulations in the tropics and mid-latitudes. However, differences in these variabilities are most pronounced in the regions of the western boundary currents and Antarctic Circumpolar Current, primarily due to variations in thermosteric sea level (TSSL) and halosteric sea level. In contrast, the DSL variability differences in the Southern Ocean are mainly due to the TSSL. Analyses of ocean heat content (OHC) budgets suggest that the differences between the LICOM2-L and LICOM2-H simulations are mainly in decadal variability and long-term trends. The interannual and decadal variabilities of OHC are significantly influenced by both large-scale mean advection and eddy-induced transport. The latter plays a more pronounced role in high-latitude regions and contributes notably to decadal variability and trend differences. At the equator, eddy-induced transport is the primary driver of long-term trends, accounting for 80% of the total contribution, while the large-scale mean advection contributes the remaining 20%. These findings underscore the complex interplay between mean advection and eddy processes in shaping the thermohaline structure and sea-level variability in the ocean models.

Distribution and controlling factors of dissolved inorganic carbon in urban rivers of a North China megacity: Insights from δ13CDIC.

Transportation and transformation of the dissolved inorganic carbon (DIC) play a critical role in the regional carbon cycle. To clarify the natural and anthropogenic impacts on DIC, the concentration and isotopic composition of DIC (δ13CDIC) in two typical urban rivers in northern China (Yongding River, YDR, and Chaobai River, CBR) were measured. Mass-balanced calculations were employed to quantify the impacts of different weathering processes. The results indicated that carbonate weathering under the influence of mixed weathering agents was the primary weathering process in the YDR and CBR. Carbonate dissolution by carbonic acid was an important source of DIC in both the YDR and the CBR. According to the end-member calculations of δ13CDIC, soil-respiration CO2 was a key factor controlling the carbonate weathering by carbonic acid. A high contribution of sulfuric and nitric acids to carbonate weathering was found in the YDR, especially in downstream areas with high-level anthropogenic activities. This indicated that anthropogenic activities can profoundly impact the weathering processes in watersheds. This study provides insights into the complex interactions between human activities and natural processes in shaping the carbon dynamics of urban rivers, highlighting the importance of natural and anthropogenic factors on carbon dynamics in urban rivers and providing insights essential for predicting carbon flux changes amidst urbanization and climate change.

Research on the 3D printing process and filament shape of cementitious materials in low gravity

Research on the 3D printing process and filament shape of cementitious materials in low gravity

Coupling metabolomics and exome sequencing reveals graded effects of rare damaging heterozygous variants on gene function and human traits

Genetic studies of the metabolome can uncover enzymatic and transport processes shaping human metabolism. Using rare variant aggregation testing based on whole-exome sequencing data to detect genes associated with levels of 1,294 plasma and 1,396 urine metabolites, we discovered 235 gene–metabolite associations, many previously unreported. Complementary approaches (genetic, computational (in silico gene knockouts in whole-body models of human metabolism) and one experimental proof of principle) provided orthogonal evidence that studies of rare, damaging variants in the heterozygous state permit inferences concordant with those from inborn errors of metabolism. Allelic series of functional variants in transporters responsible for transcellular sulfate reabsorption (SLC13A1, SLC26A1) exhibited graded effects on plasma sulfate and human height and pinpointed alleles associated with increased odds of diverse musculoskeletal traits and diseases in the population. This integrative approach can identify new players in incompletely characterized human metabolic reactions and reveal metabolic readouts informative of human traits and diseases.

Wisdom as an Ethical Goal in the Professional Role of a Pedagogue

Introduction: The topic of the article concerns the category of wisdom from the perspective of the role it plays in the profession of pedagogue. Wisdom was presented as the objective of professional development, with particular emphasis on its ethically non-neutral nature. The analyzes of the wisdom category were related to the broader axiological context and the perception of wisdom through the ethical prism of good. Research Aim: The aim of the research is to pay special attention to the place and role of wisdom in the education of pedagogues, and not only its importance as a objective in the educational process. The idea is to show the ethical side of what wisdom is and what benefits would come from promoting the approximative nature of developing wisdom. Moreover, the emphasis in the text is on the conversion of knowledge into values and the phenomenon of axiological internalization as a key process in shaping the reflective, autonomous and responsible attitude of a wise pedagogue. Evidence-based Facts: The article refers in an interdisciplinary way to the views of researchers who particularly emphasize the importance of wisdom for human development. In the presented analyses, the Socratic vision of wisdom, closely related to good, was particularly highlighted. The text also emphasizes that in preparing pedagogues for their profession, the category of wisdom should play a particularly significant role due to the fact that ethical tasks in this profession go beyond knowledge or qualifications. Summary: the close connection between wisdom and good cannot leave one indifferent to the place and importance of the category of wisdom in the process of preparing pedagogues for their profession. Wisdom brings with it ethical objective and emphasizes the axiological context of pedagogical work, which is not free from normative meanings. Moral competences are therefore an integral part of training for the professional role of a pedagogue.

Sedimentary facies and grain size distribution; Insights into Ogwashi-Asaba Formation, Niger Delta Basin

The Niger Delta is renowned for being one of the most productive hydrocarbon provinces globally. This productivity is primarily attributed to its complex geological history, which is marked by intricate stratigraphy and various sedimentary facies. These sedimentary facies, which are distinct bodies of sediment with specific characteristics, provide essential information about past environments and sedimentary processes, about the complex stratigraphy and diverse sedimentary facies. Stratigraphic sequences in the Niger Delta include alternating layers of sandstones, shales, and siltstones. Sediment samples were collected with cores too, from the Ogwashi-Asaba formation, and a detailed field analysis was documented. Grain size, petrographic, and geochemical analysis were carried out in the lab, from the samples collected. The analyzed parameters suggest that the sandstone samples from the Ogwashi-Asaba Formation are predominantly fluviatile. Graphic Mean (Mz) ranges from 1.4 to 2.1 phi. Grain Size Composition 2-20% very fine sand, 6-66% fine sand, 45-87% medium to coarse sand, and 70-100% very coarse sand. Sorting (σ1) ranges from 1.1 to 2.1 phi, with 64.71% of sediments being very poorly sorted and 35.29% poorly sorted. Graphic Skewness (Sk) ranges from -0.6 to +0.5, indicating varying energy conditions. Graphic Kurtosis (KG): Ranges from 0.8 to 1.9, with curves varying from leptokurtic to platykurtic. These sedimentary processes shaping the Ogwashi-Asaba formation creates a diverse stratigraphy and a variety of sedimentary facies. Each provides valuable insights into past environmental conditions and sedimentary dynamics. A comprehensive understanding of these processes enhances the potential for hydrocarbon exploration and the reservoir characterization of the province.

Investment casting of Cr–Si alloys with liquidus temperatures up to 1900 °C

AbstractIn previous studies, chromium–silicon-based alloys have shown promising material properties for high-temperature applications. For chromium–silicon alloys to be processed on a large scale, primary shaping processes must be adapted to the requirements of these alloys. In this work, binary chromium–silicon alloys are primarily shaped using an investment casting process. Ceramic shell molds made of hafnium oxide stabilized zirconium oxide are developed to withstand the thermal, mechanical and chemical stresses resulting from pouring melts with liquidus temperatures of up to 1900 °C. The layered construction of the shell molds leads to a sufficient thermal shock stability. Energy-dispersive X-ray spectroscopy shows that chemical interactions between the shell mold and the melt do not occur, nor oxides are formed to a detectable extent. Microstructure investigations reveal that casting binary chromium–silicon alloys lead to a coarse grain structure with grain diameters above 300 µm. Strength-increasing precipitations of the intermetallic phase Cr3Si (A15 phase) can be detected from a silicon content of seven-atom percent in the as-cast state.

Segmentation of the Active Fault on the Cirebon-Semarang Segments as Revealed by DEM-Derived Geomorphic Indices

This research focuses on the segmentation and tectonic activity of the Baribis-Kendeng Fault across the Cirebon to Semarang segments, revealed through the analysis of geomorphic indices derived from Digital Elevation Models (DEM). Utilizing geomorphic indices such as the Hypsometric Integral (HI), Stream Length-Gradient Index (SL), and SL/K ratio, the analysis was conducted on 33 streams crossing ten segments. The results indicate that the landscape in the research area is predominantly in the youthful stage, with HI values ranging from 0.459 to 0.492, indicating active tectonic uplift. Segments such as Ungaran and Pemalang exhibit significant tectonic activity, with high SL/K values, particularly in the Ungaran segment, where the SL/K value reaches 344.872. These findings suggest that fault activity in the region is ongoing, with stronger uplift patterns observed at the western and eastern ends of the fault, while relatively lower activity is found in the central area. This research highlights the ongoin tectonic processes shaping the region’s geomorphology and contributes to a better understanding of the active fault system in Java Island.

Convergent Patterns of Karyotype Evolution Underlying Karyotype Uniformity in Conifers.

Karyotype diversity plays an important role in speciation and diversification. However, gymnosperms, particularly conifers, exhibit remarkable karyotype uniformity. To explore the evolutionary processes shaping karyotypes in gymnosperms, the karyotype evolutionary history is reconstructed through comparative genomic analyses. Synteny analysis confirms the absence of ancient polyploidy in conifers and its rarity across the gymnosperms as a whole. Further analysis reveals convergent patterns of reciprocal translocations between nonhomologous chromosomes in conifer genomes. Centromeric-centromeric reciprocal translocations (CRTs) have been identified as the primary mechanism of karyotype evolution in conifers, while telomeric-centromeric reciprocal translocations (TRTs) significantly contributed to descending dysploidy within Cupressales. A graph-based method is utilized to infer the detailed evolutionary pathways from the proto-gymnosperm karyotype (n = 12) to modern conifer karyotypes (n = 11-12). In conclusion, the scarcity of both polyploidy and dysploidy contributes to the karyotype uniformity of gymnosperms and potentially also to their lower species richness compared to angiosperms. However, the pervasive CRTs and occasional TRTs underlie this "apparent uniformity", supporting the "karyotype orthoselection" hypothesis. This study provides new insights into the mechanisms maintaining karyotype uniformity in conifers and the role of karyotype evolution in their diversification.

Subiasiana indica gen. nov., sp. nov., a new remarkable representative of Uropodina mites from India (Acari: Mesostigmata: Uropodidae)

A new genus, Subiasiana gen. nov. (Mesostigmata: Uropodina: Uropodidae), with Subiasiana indica sp. nov. as type species, is described based on one female and four males in soil samples from India. The new genus is similar to the Neotropical genus Clausiadinychus Sellnick, 1930 (family Clausiadinychiidae Kontschán, Ermilov & Fridrich, 2023), but its gnathosomal appendages and the ventral setation are different from those of the new genus. The new genus resembles the Afrotopical genus Spinosissuropoda Hirschmann, 1979, but the new genus differs from the previously described one in the shape of idiosoma, dorsal setation, and anterior gnathosoma process.

Comparison of Crustal Stress and Strain Fields in the Himalaya–Tibet Region: Geodynamic Implications

The Himalaya–Tibet region represents a complex region of active deformation related to the ongoing India–Eurasia convergence process. To provide additional constraints on the active processes shaping this region, we used a comprehensive dataset of GNSS and focal mechanisms data and derived crustal strain and stress fields. The results allow the detection of features such as the arc-parallel extension along the Himalayan Arc and the coexistence of strike-slip and normal faulting across Tibet. We discuss our findings concerning the relevant geodynamic models proposed in the literature. While earlier studies largely emphasized the role of either compressional or extensional processes, our findings suggest a more complex interaction between them. In general, our study highlights the critical role of both surface and deep processes in shaping the geodynamic processes. The alignment between tectonic stress and strain rate patterns indicates that the crust is highly elastic and influenced by present-day tectonics. Stress and strain orientations show a clockwise rotation at 31°N, reflecting deep control by the underthrusted Indian Plate. South of this boundary, compression is driven by basal drag from the underthrusting Indian Plate, while northward, escape tectonics dominate, resulting in eastward movement of the Tibetan Plateau. Localized stretching along the Himalaya is likely driven by the oblique convergence resulting from the India–Eurasia collision generating a transtensional regime over the Main Himalayan Thrust. In Tibet, stress variations appear mainly related to changes in the vertical axis, driven by topographically induced stresses linked to the uniform elevation of the plateau. From a broader perspective, these findings improve the understanding of driving crustal forces in the Himalaya–Tibet region and provide insights into how large-scale geodynamics drives surface deformation. Additionally, they contribute to the ongoing debate regarding the applicability of the stress–strain comparison and offer a more comprehensive framework for future research in similar tectonic settings worldwide.

The Impact of Influencers on Adolescent Behavior: Study of Attitudes and Decision-Making

This study examined the impact of social media influencers on the attitudes, values, and choices of 100 adolescents, addressing a gap in understanding adolescents' mental models regarding influencer content (Lajnef, 2023) [14]. A quantitative correlational design employing repeated measures ANOVA analyzed data from participants exhibiting diverse behaviors and decision-making patterns. The study utilized a survey instrument measuring perceptions across six dimensions: Intellectual, social, ethical, health, exposure to influencers, and decision-making. Results revealed a significant influencer impact (F(5, 95) = 17.69, p < .001, η²p = .15), demonstrating a large effect size on purchasing decisions, promotion of unhealthy lifestyles, and the shaping of attitudes and decision-making processes. This influence carries significant mental health implications, underscoring the need for critical thinking and media literacy skills. Post-hoc tests using Bonferroni correction revealed significant differences among the dimensions. Intellectual engagement was rated most positively, while ethical considerations elicited the most ambivalent responses. Specifically, participants perceived significant positive impacts on intellectual development and learning but expressed concerns about the ethical implications of influencer behavior and the potential for negative impacts on mental and physical health. Further research is needed to fully understand the underlying cognitive processes and long-term effects, considering cultural context and individual differences. The findings emphasize the urgent need for comprehensive media literacy programs, collaborative efforts among parents, educators, and policymakers, and the establishment of open dialogue platforms to promote healthy social media engagement and responsible decision-making among adolescents. The dual nature of influencer impact—positive contributions to intellectual growth alongside concerns about ethical behavior, health, and decision-making—requires further investigation.

Epistemic Governance in the Context of Crisis: A Complexity-informed Approach

This article examines the concept of epistemic governance during crises, a situation that presents simultaneous challenges of information scarcity and overload. Epistemic governance refers to the processes shaping collective perceptions and influencing the understanding of a situation. The research employs a complexity thinking approach, focusing on the interdependency of phenomena, actors, and events, which resists reductionism and linear thinking. It illustrates how epistemic governance—comprising self-organization, diversity, trust, feedback loops, attractor, and agency—operates in crises. The study advances a novel approach to epistemic governance in crises, promoting effective decision-making and embracing complexity-informed research.

An Enhanced Bioactive Glass Composition with Improved Thermal Stability and Sinterability.

The development of new bioactive glasses (BGs) with enhanced bioactivity and improved resistance to crystallization is crucial for overcoming the main challenges faced by commercial BGs. Most shaping processes require thermal treatments, which can induce partial crystallization, negatively impacting the biological and mechanical properties of the final product. In this study, we present a novel bioactive glass composition, S53P4_MSK, produced by a melt-quench route. This novel composition includes magnesium and strontium, known for their therapeutic effects, and potassium, recognized for improving the thermal properties of bioactive glasses. The thermal properties were investigated through differential thermal analysis, heating microscopy and sintering tests from 600 °C to 900 °C. These characterizations, combined with X-ray diffraction analysis, demonstrated the high sinterability without crystallization of S53P4_MSK, effectively mitigating related issues. The mechanical properties-elastic modulus, hardness and fracture toughness-were evaluated on the sintered sample by micro-indentation, showing high elastic modulus and hardness. The bioactivity of the novel BG was assessed following Kokubo's protocol and confirmed by scanning electron microscopy, X-ray energy dispersive spectroscopy, and Raman spectroscopy. The novel bioactive glass composition has shown high sinterability without crystallization at 700 °C, along with good mechanical properties and bioactivity.

Dynamic Impact of One-Year Integrated Rice-Crayfish Farming on Bacterioplankton Communities in Paddy Water.

As global food security issues become increasingly severe, an important innovation in agricultural production patterns, namely integrated rice-fish farming, has been widely implemented around the world, especially in Asia. To assess the impact of integrated rice-crayfish (Procambarus clarkii) farming (IRCF) on agricultural ecosystems, we used Illumina high-throughput 16S rRNA gene sequencing to analyze differences in diversity, composition, co-occurrence network, and assembly process of planktonic bacterial communities in paddy water between traditional rice farming (TRM) and IRCF. Environmental factors and planktonic bacterial communities were evaluated during the tillering, jointing, flowering, and grain-filling stages on August 24, September 5, September 24, and October 16, respectively. Our findings revealed that, throughout the entire cultivation period, IRCF had no notable impacts on bacterioplankton community diversity in paddy water, but it changed the composition and relative abundance of the dominant bacterioplankton. Specifically, IRCF promoted the Chloroflexota during the tillering stage but reduced its presence during the grain-filling stage. It also significantly decreased the Bacillota during the jointing stage while notably enhancing Actinomycetota during the flowering stage. Furthermore, IRCF markedly improved the robustness and negative/positive cohesion within bacterioplankton co-occurrence networks during jointing and grain-filling stages. IRCF altered the assembly processes shaping planktonic bacterial communities, promoting a greater dominance of stochastic processes during the tillering, jointing, and flowering stages and a diminished dominance during the grain-filling stage. IRCF dramatically changed aquatic environmental factors, particularly during the jointing stage, by substantially increasing the TN, ammonium, nitrate, and phosphate levels in paddy water. These nutrient levels were closely correlated with the dynamics of the planktonic bacterial communities. Our findings underscore the considerable potential of IRCF in enhancing the stability of bacterioplankton communities and promoting rice growth while also providing valuable data and theoretical insights into the microbiological ecological impacts of IRCF on the agroecosystem.

Edges of perception: balancing sensory loss and potential in assistive technology

Being deafblind means my perception differs profoundly from those who are conventionally sighted and have non-impaired hearing. A lot of hidden knowledge is to be found in the disparity between...

Curricular Differentiation and Informal Networks: How Formal Grouping and Ranking Practices Shape Friendships among Students in College

This study draws on complete friendship network data on two first-year biological sciences cohorts at a selective university in the United States to investigate how and to what extent allocating students to curricular groups and grading their performance in class shape (1) processes of friend selection at the dyadic level and (2) friendship clustering at the network level. Through a set of stochastic actor-oriented models, results show that students tend to befriend peers from the same curricular group versus a different one (i.e., curricular group homophily) and befriend higher-performing peers (i.e., performance-based status). Follow-up analyses reveal that friendship clustering by curricular group placement is largely due to course co-enrollment (i.e., proximity), whereas academic-performance-based clustering is primarily the result of students aligning their own performance to match the average performance of their friends (i.e., influence). I discuss implications of these findings for helping to promote learning in higher education.