Search Results (110)

This study investigates the impact of environmental, social, and governance (ESG) disclosure on value creation in a balanced panel of 100 non-financial Sharia-compliant firms listed on the Saudi Stock Exchange over the period 2014–2023. The analysis employs a combination of econometric techniques, including fixed effects models with Driscoll–Kraay standard errors, Pooled Ordinary Least Squares (POLS) with Driscoll–Kraay standard errors and industry and year dummies, and two-step system generalized method of moments (GMM) estimation to address potential endogeneity and omitted variable bias. Value creation is measured using Tobin’s Q (TBQ), Return on Assets (ROA), and Return on Equity (ROE). The models also control for firm-specific variables such as firm size, leverage, asset tangibility, firm age, growth opportunities, and market capitalization. The findings reveal that ESG disclosure has a positive and statistically significant effect on firm value across all three performance measures. Furthermore, firm size significantly moderates this relationship, with larger Sharia-compliant firms experiencing greater value gains from ESG practices. These results align with agency, stakeholder, and signaling theories, emphasizing the role of ESG in enhancing transparency, reducing information asymmetry, and strengthening stakeholder trust. The study provides empirical evidence relevant to policymakers, investors, and firms striving to achieve Saudi Arabia’s Vision 2030 sustainability goals. Full article

This study investigates the dynamic relationship between maritime trade and cultural convergence between China and Saudi Arabia, with a particular focus on the roles of creative goods and information and communication technology (ICT) exports as proxies for sociocultural integration. Utilizing quarterly data from 2012 to 2021, the analysis employs the Toda–Yamamoto Granger causality approach within a Vector Autoregression (VAR) framework. This methodology offers a robust means of testing causality without requiring data stationarity or cointegration, thereby reducing estimation bias and enhancing applicability to real-world economic data. The empirical model examines causal interactions among maritime trade, creative goods exports, ICT exports, and population, the latter serving as a control variable to account for demographic scale effects on trade dynamics. The results indicate statistically significant bidirectional causality between maritime trade and both creative goods and ICT exports, suggesting a reciprocal reinforcement between trade and cultural–technological exchange. In contrast, the relationship between maritime trade and population is found to be unidirectional. These findings underscore the strategic importance of cultural and technological flows in shaping maritime trade patterns. Furthermore, the study contextualizes its results within broader policy initiatives, notably China’s Belt and Road Initiative and Saudi Arabia’s Vision 2030, both of which aim to promote mutual economic diversification and regional integration. The study contributes to the literature on international trade and cultural economics by demonstrating how cultural convergence can serve as a catalyst for strengthening bilateral trade relations. Policy implications include the promotion of cultural and technological collaboration, investment in maritime infrastructure, and the incorporation of cultural dimensions into trade policy formulation. Full article

The effect of severe plastic deformation during milling and conventional and Spark Plasma Sintering (SPS) on the wt. % microstructural, structural, thermal, magnetic, and mechanical properties of the Al–16 wt. % Mn–7 wt. % Cu alloy was studied. A milling process for up to 24 h (A24) leads to microstructure refinement and the presence of Al, Mn, and Cu solid solutions. The energy dispersive spectroscopy (EDS) analysis reveals the existence of Cu–Al, Mn–Al, and Al–Mn enriched particles. The powders exhibit weak ferromagnetism and an exchange bias (EB) behaviour that decreases with increasing milling time. The Ms values fitted using the law of approach to saturation (LAS) are comparable to the experimental values. The exothermic and endothermic peaks that appear in the differential scanning calorimetry (DSC) scans in the 500–900 °C range on heating/cooling are related to different phase transformations. The crystal structure of the A24 powders heated up to 900 °C (A24_900 °C) consists of a dual-phase microstructure of Al₂₀Cu₂Mn₃ nanoprecipitates (~28%) and Al matrix (~72%). The sintering of the A24 powders at 500 °C for one hour (A24S) leads to the precipitation of Al₆Mn, Al₂Cu, and the Al₂₀Cu₂Mn₃ T-phase into the Al-enriched matrix. In contrast, the consolidation by SPS (A24SPS) leads to a mixture of an Al solid solution, Al₆Mn, T-phase, and α-Mn with an increased weight fraction of the T-phase and Al₆Mn. The sintered samples exhibit the coexistence of a significant PM/AFM contribution to the M-H curves, with increasing Hc and decreasing EB. A higher microhardness value of about 581 HV is achieved for the A24SPS sample compared to those of the A24 (68 HV) and A24S (80 HV) samples. Full article

In this research, an analysis of the thermomagnetic properties of a nanoscale spin-2 and spin-3/2 system is conducted. This system is modeled with as a quasi-spherical Ising-type nanoparticle with a diameter of 2 nm, in which atoms with spin-2 and spin-3/2 configured in body-centered cubic (BCC) lattices interact within their relevant nanostructures. To determine the thermomagnetic behaviors of the nanoparticle, numerical simulations using Monte Carlo techniques and thermal bath class algorithms are performed. The results exhibit the effects of exchange couplings ($J_1,J_2^{\prime }$), magnetocrystalline anisotropies ($D_{3/2}^{\prime },D_2^{\prime }$), and external magnetic fields ($h^{\prime }$) on the finite-temperature phase diagrams of magnetization ($M_T$), magnetic susceptibility (${\chi }_T$), and thermal energy ($k_B{T}^{\prime }$). The influences of the exchange, anisotropic, and external field parameters are clearly reflected in the compensation, hysteretic, and pseudocritical phenomena presented by the quasi-spherical nanoparticle. When the parameter reflecting ferromagnetic second-neighbor exchanges in the nanosphere ($J_2^{\prime }$) increases, for a given value of the external magnetic field, the compensation ($T_{comp}$) and pseudocritical ($T_{pc}$) temperatures increase. Similarly, in the ranges $0<J_2^{\prime }⩽4.5$ and $-15⩽h^{\prime }⩽15$ at a specific temperature, an increase in $J_2^{\prime }$ results in the appearance of exchange anisotropies (exchange bias) and and increased hysteresis loop areas in the nanomodel. Full article

Background: Copper dyshomeostasis has been implicated in a subset of Alzheimer’s disease (AD) patients, characterized by elevated non-ceruloplasmin-bound copper (non-Cp Cu). However, traditional methods for estimating non-Cp Cu are indirect and analytically imprecise. This study introduces and validates a direct assay for exchangeable copper (ExcCu) by inductively coupled plasma-mass spectrometry (ICP-MS), compliant with Clinical and Laboratory Standards Institute (CLSI) guidelines. Methods: We performed analytical validation of the ExcCu assay following CLSI protocols (EP5, EP6, EP7, EP9, EP15, and EP28). ExcCu and other copper-related biomarkers were quantified in serum samples from 154 healthy controls, 82 AD patients, and 10 patients with Wilson disease (WD). Diagnostic performance was evaluated via receiver operating characteristic (ROC) curve analysis, and inter-method agreement was assessed using Bland–Altman plots. Results: The ExcCu assay demonstrated excellent linearity, precision (CV < 6%), and inter-laboratory reproducibility. Among AD patients, ExcCu levels were significantly elevated compared to controls (p < 0.001). ExcCu distinguished AD from controls with an AUC of 0.80 and a specificity of 95%. Compared to non-Cp Cu, ExcCu yielded no negative values and showed reduced bias. The relative exchangeable copper (REC) index was more effective in differentiating AD from WD (AUC = 0.88). Conclusions: The validated ExcCu assay overcomes the limitations of the traditional non-Cp Cu calculation, offering a reliable biomarker for copper-related AD subtypes. Its high specificity supports its use in patient stratification, potentially contributing to personalized approaches in AD diagnosis and therapy. Full article

The sea surface temperature (SST) is an important parameter reflecting the energy exchange between the ocean and the atmosphere, which has a key impact on climate change, marine ecology and fisheries. However, most of the existing SST fusion methods suffer from poor portability and a lack of consideration of cloudy conditions, which can affect the data accuracy and reliability. To address these problems, this paper proposes an infrared and microwave SST fusion method based on cloudy conditions. The method categorizes the fusion process according to three scenarios—clear sky, completely cloudy, and partially cloudy—adjusting the fusion approach for each condition. In this paper, three representative global datasets from home and abroad are selected, while the South China Sea region, which suffers from extreme weather, is used as a typical study area for validation. By introducing the buoy observation data, the fusion results are evaluated using the metrics of bias, RMSE, URMSE, r and coverage. The experimental results show that the biases of the three fusion results of VIRR-RH, AVHRR-RH and MODIS-RH are −0.611 °C, 0.043 °C and 0.012 °C, respectively. In the South China Sea region under extreme weather conditions, the bias is −0.428 °C, the RMSE is 0.941 °C, the URMSE is 0.424 °C and the coverage rate reaches 25.55%. These results confirm that this method not only produces significant fusion effects but also exhibits strong generalization and adaptability, being unaffected by specific sensors or regions. Full article

This study assesses the potential impact of climate change on hydropower generation, focusing on the Grand Inga hydropower project on the Congo River in the Democratic Republic of Congo. Utilizing a multi-input approach with a conceptual HEC-HMS hydrologic model, this research incorporates a new bias-corrected high-resolution daily downscaled dataset, NASA Earth Exchange Global Daily Downscaled Projections (NEX-GDDP CMIP6), and its predecessor (CMIP5) under various climate scenarios. The hydropower generation at Inga Falls is simulated using a hydropower model, considering observed and simulated daily flows for different climate models and emission scenarios. The results suggest that the Grand Inga project will be resilient to negative climate impacts during its initial phases (1–5). The system demonstrates security and insensitivity to adverse changes, both for existing (Phase 1–2) and planned (Phase 3–5) hydropower components. This study indicates that climate change effects become apparent only in later phases (6–8), with predominantly positive impacts, potentially increasing the generation potential of the hydropower system. Overall, the Grand Inga hydropower project appears robust against adverse climate influences throughout the majority of its development phases. Full article

Perovskite-type materials containing Bi³⁺ cations at A sites are interesting from the viewpoints of applications and fundamental science as the lone pair of Bi³⁺ cations often stabilizes polar, ferroelectric structures. This can be illustrated by a lot of discoveries of different new functionalities in bulk and thin films of BiFeO₃ and its derivatives. In this work, we investigated solid solutions of BiCr_1−xFe_xO₃ with 0.1 ≤ x ≤ 0.4 prepared by a high-pressure (HP) method and post-synthesis annealing at ambient pressure (AP). HP-BiCr_1−xFe_xO₃ modifications with 0.1 ≤ x ≤ 0.3 were mixtures of two phases with space groups C2/c and Pbam, and the amount of the C2/c phase decreased with increasing x. The amount of the C2/c phase was also significantly decreased in AP-BiCr_1−xFe_xO₃ modifications, and the C2/c phase almost disappeared in AP-BiCr_1−xFe_xO₃ with 0.2 ≤ x ≤ 0.3. Fundamental, strong reflections of HP-BiCr_1−xFe_xO₃ and AP-BiCr_1−xFe_xO₃ were almost unchanged; on the other hand, weak superstructure reflections were different and showed clear signs of strong anisotropic broadening and incommensurate positions. These structural features prevented us from determining their room-temperature structures. On the other hand, HP-BiCr_1−xFe_xO₃ and AP-BiCr_1−xFe_xO₃ showed high-temperature structural phase transitions to the GdFeO₃-type Pnma modification at T_srt = 450 K (x = 0.1), T_srt = 480 K (x = 0.2), T_srt = 510 K (x = 0.3), and T_srt = 546 K (x = 0.4). Crystal structures of the GdFeO₃-type Pnma modifications of all the samples were investigated by synchrotron powder X-ray diffraction. Magnetic properties of HP-BiCr_1−xFe_xO₃ and AP-BiCr_1−xFe_xO₃ were quite close to each other (HP vs. AP), and the x = 0.2 samples demonstrated negative magnetization phenomena without signs of the exchange bias effect. Full article

Exchange-biased specimens were produced by molecular beam epitaxy (MBE) of ferromagnetic (FM) Co-on-CoO substrates after the substrates had been irradiated by heavy ions to induce defects in the antiferromagnet (AFM). Measurements were obtained at different temperatures for different sample orientations with respect to the external magnetic field. While the EB was relatively small, measurements of the bulk magnetization at low temperatures revealed unusually shaped hysteresis loops. The surface magnetization, however, showed simple, nearly rectangular hysteresis loops. This study focuses on the advantage of complementary information on surface and bulk magnetization from optical and non-optical measurement methods. Full article

Bias instability is one of the most critical factors in the performance of spin-exchange relaxation-free (SERF) co-magnetometers. Previous studies on SERF co-magnetometers have shown that changes in the atomic ensemble temperature can lead to variations in the alkali metal atom density, which in turn affect the optical rotation angle and light shift, ultimately influencing the system’s stability. Building on this understanding, this paper introduces the thermoelectric analogy method for the first time in the transient heat transfer analysis of SERF co-magnetometer atomic ensembles. Using this method, the primary factors affecting the atomic ensemble temperature in a SERF co-magnetometer were analyzed, and transient heat transfer models were established for the following processes: the interaction between the non-magnetic electric heating system and the atomic ensemble temperature, laser heating of the atomic ensemble by the optical system, and the effect of environmental temperature changes on the non-magnetic electric heating system. These models were experimentally validated through active temperature variation experiments. The experimental results show that the proposed transient heat transfer models accurately describe the related heat transfer processes of the atomic ensemble, with model fitting accuracy exceeding 98%. This lays a solid foundation for the high-precision closed-loop control of the atomic ensemble temperature in SERF co-magnetometers and provides valuable insights for the structural design and engineering applications of SERF co-magnetometers. Full article

Artificial heterostructures are typically created by layering distinct materials, thereby giving rise to unique characteristics different from their individual components. Herein, two-dimensional α-MnSe nanosheets with a non-layered structure were fabricated on Ga_0.6Fe_1.4O₃ (GFO) films. The superior crystalline properties of MnSe/GFO heterostructures were confirmed through structural and morphological analyses. The remanent polarization is around 1.5 μC/cm² and the leakage current density can reach 2 × 10⁻³ A/cm² under 4 V. In addition, the piezo-response force microscopy amplitude and phase images further supported the ferroelectric property. The significant improvement of coercive field and saturated magnetization, along with the antiparallel signals of Mn and Fe ions observed through synchrotron X-ray analyses, suggest the presence of magnetic interaction within the MnSe/GFO heterostructure. Finally, the excellent photodetector with a photo detectivity of 6.3 × 10⁸ Jones and a photoresponsivity of 2.8 × 10⁻³ A·W⁻¹ was obtained under 532 nm in the MnSe/GFO heterostructure. The characteristics of this heterostructure, which include multiferroic, magnetic exchange bias effect, and photodetection capabilities, are highly beneficial for multifunctional devices. Full article

The exchange bias (EB) effect denotes a magnetic bias phenomenon originating from the interfacial exchange coupling at the ferromagnetic/antiferromagnetic materials, which plays an indispensable role in the functionality of various devices, such as magnetic random-access memory (MRAM) and sensors. Voltage control of exchange bias offers a promising pathway to significantly reduce device power consumption, effectively fostering the evolution of low-energy spintronic devices. The “magneto-ionic” mechanism, characterized by its operational efficiency, low energy consumption, reversibility, and non-volatility, provides innovative approaches for voltage control of exchange bias and has led to a series of significant advancements. This review systematically synthesizes the research progress on voltage control of exchange bias based on the magneto-ionic mechanism from the perspectives of ionic species, material systems, underlying mechanisms, and performance parameters. Furthermore, it undertakes a comparative evaluation of the voltage-controlled exchange bias by different ions, ultimately providing a forward-looking perspective on the future trajectory of this research domain. Full article

The acquisition, integration, and exchange of digital technologies considerably contribute to the improvement of corporate innovation quality, as autonomous vehicles are a complex amalgamation of multiple industrial chains. In order to address the intense global competition in the autonomous vehicles industry and help China’s enterprises establish a prominent position in technological innovation, this study innovatively integrates the concepts of digital empowerment, digital platform capabilities, and boundary-spanning search into a cohesive framework, examines the pathways of influence, and methodically builds a multiple-chain mediation model. It employs various quantitative models, such as reliability and validity testing, confirmatory factor analysis, common method bias testing, mediation effect analysis, and robustness testing. The study focuses on over a hundred companies related to autonomous vehicles in China, employing software such as SPSS26.0, AMOS26.0, PROCESS4.0, and MPLUS8.3 to conduct this analysis. The findings indicate that digital empowerment is a critical factor in the improvement of innovation quality within autonomous vehicle companies. The relationship between digital empowerment and innovation quality is partially mediated by digital platform capabilities, and the boundary-spanning search also functions as a partial intermediary. Additionally, the quality of innovation and digital empowerment are mediated by the boundary-spanning search and the capabilities of digital platforms. The results of this study provide valuable insights on how to accurately empower the high-quality development of the autonomous vehicle sector with digital technologies, revealing new perspectives on the innovation quality enhancement pathways for autonomous vehicle companies in China, offering pivotal insights amidst the escalating competition within the global autonomous vehicle sector. Full article

Background: Oestradiol has been implicated as a factor in substrate utilisation in male and mouse studies but the effect of acute changes during the menstrual cycle is yet to be fully understood. Objective: To determine the role of oestradiol in respiratory exchange ratio (RER) during exercise at various intensities. Methods: This systematic review was conducted and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. From inception to November 2023, four online databases (Cochrane, SPORTDiscus, MEDline and Web of Science) were searched for relevant articles. Studies that reported a resting oestradiol measurement in naturally menstruating women with exercise at a percentage of maximal aerobic capacity (%V˙O_2max) were included. Mean and standard deviation for oestradiol, RER and exercise intensity were extracted and study quality assessed using a modified Downs and Black checklist. Risk of bias was assessed using I₂ measure of heterogeneity and Egger’s regression test, assessment of bias from methodological quality was identified by sensitivity analysis. Eligible datasets were extracted for pairwise comparisons within a meta-analysis and correlation between change in oestradiol and change in RER. Data were also pooled to produce a mean and standard deviation for RER for menstrual stage and for low and high oestradiol groups. Results: Twenty-four articles were identified, over 50% were identified as high quality. Sixteen articles included datasets eligible for meta-analysis. Eleven articles utilised a submaximal constant-load exercise intensity, finding a standardised mean difference of − 0.09 ([CI: −0.35–0.17], p = 0.5) suggesting no effect of menstrual phase on constant-load exercise RER. In six articles using incremental exercise tests to exhaustion, a standardised mean difference of 0.60 ([CI 0.00–1.19], p = 0.05) was identified towards a higher maximal RER attained in follicular compared to luteal phase. There was no correlation (R = −0.26, p = 0.2) between change in oestradiol and change in RER between phases. All 24 articles, totalling 650 participants, were included in pooled analysis. When grouped by menstrual cycle phase or when grouped by oestradiol levels, RER was higher in the follicular phase than the luteal phase at low and high constant load exercise intensities. Discussion: Findings from the pooled-analysis and meta-analysis suggest that there may be menstrual cycle phase differences in RER that are intensity dependent. These differences may be related to sex hormone levels, but this was not supported by evidence of correlation between differences in RER and differences in oestradiol. At present, it remains best practice to assess performance in the same menstrual cycle phase if seeking to assess change from baseline. Full article

In order to utilize the longer wavelength light, the surface sulfurization of MoO₃ was carried out. The photocurrent responses to typical 650, 808, 980, and 1064 nm light sources with Au gap electrodes were investigated. The results showed that the surface S–O exchange of MoO₃ improved the interfacial charge transfer in the range of the broadband light spectrum. The S and O can be exchanged on the surface of MoO₃ nanosheets under the hydrothermal condition, leading to the formation of a surface MoO_x/MoS₂ heterojunction. The interfacial interaction between the MoO₃ nanosheets and MoS₂ easily generated free electrons and holes, and it effectively avoided the recombination of photogenerated carriers. Meanwhile, the surface S-doping of MoO₃ also resulted in the generation of an oxygen vacancy and sulfur vacancy on MoO_3−xS_2−y. The plasmonic characteristics of MoO_3−x contributed to the enhancement of the interfacial charge transfer by photoexcitation. Otherwise, even with zero bias applied, a good photoelectric signal was still obtained with polyimide film substrates and carbon electrodes. This indicates that the formation of the heterojunction generates a strong built-in electric field that drives the photogenerated carrier transport, which can be self-powered. This study provides a simple and low-cost method for the surface functionalization of some metal oxides with a wide bandgap. Full article