Search Results (53,724)

This study examines the relationship between governance quality and carbon intensity in Saudi Arabia over the period 2002–2024, with particular attention to the role of structural reform and institutional change. Using an autoregressive distributed lag (ARDL) framework, the analysis distinguishes between long-run equilibrium relationships and short-run adjustment dynamics in a resource-dependent economy undergoing economic transition. The long-run results indicate that capital formation significantly increases carbon intensity, suggesting that economic expansion and investment activities remain closely tied to carbon-intensive production structures and fossil-based industrial development. Renewable energy exhibits a modest mitigating effect, implying that recent progress in energy diversification has contributed to emissions efficiency, although its overall impact remains limited relative to the scale of hydrocarbon dependence. Governance does not display a robust independent long-run effect on carbon intensity. However, the interaction between governance and the post-2016 reform period is associated with lower carbon intensity, indicating that institutional quality becomes more effective when supported by broader structural transformation and policy reform initiatives. Short-run dynamics further suggest that improvements in governance may initially coincide with higher emissions intensity during transitional phases of economic adjustment and infrastructure expansion. The findings highlight that governance influences environmental performance not in isolation, but through its interaction with structural diversification, energy transition, and reform-oriented institutional change in a resource-dependent economy. Full article

Elastic springback is a critical challenge in sheet metal bending that directly affects dimensional accuracy and manufacturing efficiency. This study presents a comparative experimental and machine learning-based analysis of elastic springback behavior in three widely used sheet metals like stainless steel, aluminum, and copper, which are subjected to folding bending. The influence of key process parameters, namely sheet thickness (0.5 to 1.5 mm) and bending temperature (room temperature to 200 °C), was systematically examined under cold working. A cost-effective localized heating approach using a direct flame was introduced to enhance process control and reduce elastic recovery without the complexity associated with heated dies. Experimental results revealed substantial variability in elastic springback, ranging from 0.15% to 12.41%, emphasizing the fact that they are nonlinear in nature. Statistical evaluation confirmed that sheet thickness is the dominant factor governing elastic springback, while material type and temperature exhibit secondary yet meaningful effects. To improve predictive capability, five regression models (Linear, Polynomial, Support Vector, Random Forest, and Gradient Boosting) were developed and assessed. Among them, Random Forest demonstrated superior performance with the lowest prediction errors and strongest explanatory power, achieving an R² of approximately 0.85. Cross-validation further validated its robustness and generalization capability. Feature importance and SHapley Additive exPlanations (SHAP) analyses reinforced the primary role of thickness in determining elastic recovery behavior. The findings provide practical insights for selecting materials and process conditions to minimize elastic springback while highlighting the effectiveness of ensemble learning techniques for accurate prediction. This work contributes a consistent framework for enhancing bending precision and supports data-driven decision-making in modern manufacturing environments. Full article

Sovereign credit ratings are central to a country’s access to international capital markets, yet the relative informational content of debt service obligations versus aggregate debt stock for rating outcomes remains empirically unsettled. This systematic review synthesises econometric evidence on both measures across 23 primary studies published between 1996 and 2024. The central message of this paper is that debt service indicators—capturing near-term liquidity and refinancing pressure—are at least as informative as, and on average more informative than, debt stock ratios for sovereign credit assessments, particularly in emerging-market contexts and ordered-response specifications. This finding holds across heterogeneous study designs and is confirmed by meta-regression analysis, which shows that debt service effects are significantly more negative than debt stock effects (β = −0.09, p = 0.004) after controlling for sample composition, model family, and rating agency. Emerging-market samples and ordered-response estimators yield stronger associations than advanced-economy samples and linear (OLS) specifications. No consistent differences across the major rating agencies are found once study-design moderators are included. Because primary studies differ in model families, samples, and variable construction, we emphasise transparent reporting, avoid over-interpreting pooled magnitudes, and focus on robust qualitative patterns and moderator-based explanations of heterogeneity. The findings contribute to the literature on sovereign rating determinants and have practical implications for fiscal monitoring, suggesting that debt management aimed at improving near-term servicing capacity matters for credit assessments in ways that are not fully captured by stock-based fiscal anchors. Full article

This study investigated the impact of cobalt/nickel-silicate loadings on graphitic carbon nitride at 10% and 20% doses, designated (CoNiSi-10) and (CoNiSi-20), for the removal of ciprofloxacin (CPF), a hazardous, bioaccumulative antibiotic. The synthesized composites were characterized in detail using SEM, EDX, TEM, N₂ adsorption–desorption, XRD, and FTIR techniques. The CoNiSi-10 and CoNiSi-20 exhibited CPF q_t values of 64 and 107 mg g⁻¹, respectively, which were consistent with the surface area results. Adsorption kinetics indicated that CPF uptake on CoNiSi-10 and CoNiSi-20 fitted the Lagergren model, with the liquid-film and intraparticle-diffusion mechanisms co-governing CPF sorption. The isotherm investigations indicated CPF adsorption on CoNiSi-10 and CoNiSi-20 aligned with the Langmuir model, suggesting a homogeneous surface, while the Dubinin-Radushkevich results primarily indicated physisorption-based CPF removal. The thermodynamic analyses supported the physisorption outcome and indicated that CPF sorption onto CoNiSi-10 and CoNiSi-20 was endothermic. A five-cycle reusability test yielded average efficiencies of 94% and 96% for CoNiSi-10 and CoNiSi-20, respectively, and an after-sorption analysis indicated their stability and robustness. The ease of synthesis and excellent sorption performance may nominate CoNiSi-10 and CoNiSi-20 as promising adsorbents for treating pharmaceutically contaminated wastewater. Full article

Juvenile intestinal ischemia–reperfusion (JII/R) is a pediatric surgical emergency caused by mesenteric vessel occlusion and has a high mortality rate. Malrotation can cause intestinal ischemia in infants due to midgut volvulus. It affects not only the intestine itself but also other organs, such as cardiac tissue. Therefore, searching for more effective therapeutic solutions is an essential critical need. This directed our thoughts to evaluate the role of ambrisentan (AMB) in a rat model of induced JII/R by clamping the superior mesenteric artery. Forty juvenile male Wistar albino rats (3–4 weeks old) were randomly divided into four experimental groups: control (CON) group, JII/R group, and AMB-treated groups (30, 60 mg/kg) with JII/R. Induction of JII/R results in significant changes in cardiac enzymes, oxidative stress, inflammatory, and apoptotic parameters with high expression of endothelin receptor A (ERA). Also, histopathological changes revealed extensive mucosal damage, loss of intestinal villi, dysregulated and degenerated cardiac fibers with inflammatory cell infiltration, and tissue necrosis. In contrast, AMB administration significantly reduced the elevated levels of cardiac enzymes, malondialdehyde (MDA), nuclear factor kappa B (NF-κB), ERA, and caspase-3 expression. However, AMB treatment increased immune expressions of phosphatidylinositol 3-kinase (PI3K), protein kinase B (Akt), Ki-67, and mammalian target of rapamycin (mTOR) and showed remarkable improvement in the histopathological changes. AMB could be considered as an adjuvant medical treatment for cases of JII/R. Full article

Salivary aldehyde dehydrogenases (ALDHs), particularly ALDH3A1, are increasingly recognized as potential contributors to oral defense against aldehyde-associated stress at the oral–environment interface. Unlike freely secreted salivary enzymes, measurable salivary ALDH activity primarily reflects intracellular and vesicle-associated enzymes derived from salivary gland epithelial cells, oral mucosal cells, immune cells, and exfoliated cellular components. Within the oral exposome, ALDHs expressed in oral epithelial and salivary gland tissues participate in the detoxification of reactive aldehydes, while salivary ALDH activity may serve as an indicator of local aldehyde-detoxification capacity and tissue redox status. Beyond aldehyde metabolism, emerging evidence suggests that ALDH-associated pathways are linked to redox regulation, epithelial stress adaptation, inflammatory signaling, and tissue repair through NAD(P)⁺-dependent processes and stress-responsive networks such as Nrf2 and SIRT1. This review provides a saliva-focused synthesis of ALDH biology, emphasizing isoform-specific functions and the potential importance of ALDH3A1 in oral epithelial defense. Altered salivary ALDH activity has been reported in association with oral conditions including periodontitis, oral lichen planus, radiation-induced salivary dysfunction, and oral squamous cell carcinoma (OSCC). Genetic factors, particularly ALDH2 polymorphisms, together with environmental exposures and microbial dysbiosis, may further influence aldehyde burden and oral disease susceptibility. Although current evidence supports the biological relevance of salivary ALDHs, their utility as clinical biomarkers or therapeutic targets remains investigational and requires further mechanistic and clinical validation. Full article

This paper investigates the asymptotic stability of a one-dimensional porous elastic system subject to a single boundary control of the fractional derivative type. The system consists of two coupled hyperbolic equations describing the displacement of an elastic solid and the volume fraction, with boundary conditions that include a generalized Caputo fractional derivative of order $\alpha \in (0,1)$ at $x=L$. This configuration has not been previously addressed in the literature. Using semigroup theory, we first reformulate the system as an abstract Cauchy problem and prove that the associated operator generates a $C_0$-semigroup of contractions on a suitable energy space, establishing global well-posedness. Under explicit and generic conditions on the physical parameters and the length L, we prove strong stability via the Arendt–Batty criterion, showing that all solutions tend to zero in the energy norm as $t\to \infty$. The main result is a polynomial decay rate: there exists $c>0$ such that $\parallel S_{\mathcal{A}}\left(t\right)U_0{\parallel }_{\mathcal{H}}\le c{t}^{-1/6}{\parallel U_0\parallel }_{D\left(\mathcal{A}\right)}$ for all initial data in the domain of the generator. The proof relies on the Borichev–Tomilov theorem and a detailed contradiction argument based on asymptotic expansions of the resolvent operator. Notably, the decay rate is independent of any relation between the wave propagation speeds, which distinguishes our result from many previous studies on porous elastic or Timoshenko systems. Full article

The Cuckoo Catfish Optimizer (CCO) is a recent swarm method with four built-in movement strategies. Its weakness is not the moves themselves but the way it chooses among them: a fixed chain of random-versus-threshold ($\mathrm{rand}>C$) tests that ignores how each agent is actually doing and keeps no memory of which move has been paying off. On harder, higher-dimensional problems, this rigidity drains diversity and the search stalls. We propose CCO-RL, which hands the choice of move to a small tabular Q-learning controller. For every agent at every iteration, the controller reads a 48-state summary of the agent’s crowding, its recent stagnation and how far the run has progressed, then picks one of the four moves. A bounded reward and a decaying $\epsilon$-greedy rule let it learn a policy online with no extra function evaluations. We test CCO-RL against the original CCO and eight popular metaheuristics on CEC2017 ($D=30,50$) and CEC2022 ($D=20$): 70 instances, 30 runs each. CCO-RL earns the best overall Friedman rank ($1.69$) and significantly beats every external competitor according to the Nemenyi test. It also finds the best mean design in three engineering problems. Full article

Chronic depression is associated with oxidative stress, neuroinflammation, neurotransmitter imbalance, and Alzheimer’s-like changes. Current monoamine oxidase inhibitors have limited cognitive benefits and disease-modifying properties. A new nanotherapeutic, combining chitosan nanoparticles, propargylamino-1-(4-methylthiophenyl) propane (PAMTP), and L-tyrosine (En@PAMTP_Tyr), was developed. En@PAMTP_Tyr nanoparticles were ~140 nm in diameter, with a zeta potential of +27 mV and entrapment efficiencies of 73.45% for PAMTP and 90.85% for L-tyrosine. Drug release was pH-sensitive, favoring acidity. Intraperitoneal administration of En@PAMTP_Tyr reduced anhedonia, despair, cognitive deficits, and neuromuscular weakness, with efficacy matching or exceeding that of selegiline. In treated rats’ hippocampal tissue, En@PAMTP_Tyr increased superoxide dismutase and glutathione, normalized MAO and acetylcholinesterase activities, and corrected CUSD-induced TNF-α and IL-10 changes, showing antioxidant and anti-inflammatory effects. Histological analyses revealed that En@PAMTP_Tyr preserved CA1 pyramidal neurons, reduced β-amyloid levels, restored tau protein, and improved brain-derived neurotrophic factor levels, indicating reduced neurodegeneration. Molecular docking studies showed that PAMTP had high affinity for monoamine oxidase and acetylcholinesterase, supporting its role as an MAO-B inhibitor and cholinergic modulator. These findings suggest that En@PAMTP_Tyr is a promising nanoplatform for targeting MAO-B in depression, addressing mood, cognitive function, oxidative stress, inflammation, and Alzheimer-like pathology in the hippocampus. Full article

Faculty governance in higher education depends on transparent participation, reliable quorum enforcement, accountable record keeping, and strict alignment with institutional regulations. Conventional departmental council processes provide formal authority and academic deliberation, but they often rely on manual documentation, fragmented records, and procedural enforcement that is difficult to verify after the fact. This work presents an integrated hybrid Decentralized Autonomous Organization (DAO) framework for faculty governance that combines regulatory alignment analysis, a working smart-contract prototype, and scenario-based simulation. The framework is designed for university departmental councils and is structured across three layers: off-chain community governance, on-chain protocol governance, and off-chain execution governance. It expands prior conceptual work by incorporating governance dimensions related to roles, incentives, membership, communication, decision-making, identity, auditability, conflict-of-interest handling, and institutional ratification. The evaluation simulates 1488 proposals across twelve scenarios covering four faculty sizes (15, 30, 50, and 100 members) and three adoption levels (low, moderate, and high). Scenario results indicate that adoption intensity is the dominant driver of governance performance: mean participation increases from about 33% under low usage to about 85% under high usage, quorum achievement rises from about 6% to about 96%, and execution rises from about 19% to about 70%. Relative to a modeled conventional workflow baseline, the DAO-supported process reduces decision-cycle time by about 76%, improves audit completeness by about 30%, and increases traceability from about 0.63 to 1.00. The results indicate that DAO-assisted faculty governance can strengthen transparency, procedural consistency, and auditability while preserving legally mandated university authority, but its practical value depends on sustained participation, privacy safeguards, cost control, and clearly defined hybrid control points. Full article

Fenestration systems play a critical role in building thermal performance, particularly in cooling-dominated climates where envelope inefficiencies directly amplify electricity demand. In Saudi Arabia and other Gulf Cooperation Council (GCC) countries, cooling accounts for the majority of building energy consumption. Nevertheless, the facade and insulated glass industries are experiencing rapid market expansion. Despite this technological evolution, prevailing regulatory frameworks, including the Saudi Building Code Energy Conservation Requirements (SBC 601), ASHRAE 90.1, and the International Energy Conservation Code (IECC), primarily rely on area-weighted U-values and solar heat gain coefficients (SHGCs) without explicitly integrating multidimensional thermal bridge effects such as linear thermal transmittance (ψ). This paper examines the omission of ψ from current energy compliance systems, evaluates its implications in cooling-dominated climates, and proposes a phased regulatory integration pathway aligned with sustainability objectives under Vision 2030. Literature reports indicate that thermal bridges may increase cooling loads by up to 25% and total building energy use by 5–30%, depending on climate severity and façade configuration. The findings highlight the need to transition from simplified prescriptive compliance toward a physics-informed governance capable of addressing evolving facade complexity in hot-arid environments. The proposed framework offers a systematic pathway for integrating linear thermal transmittance requirements while supporting regional sustainability goals and advancing high-performance building technologies. Full article

A pyranochromene-based ligand, 2-amino-4-(4-chlorophenyl)-5-oxo-4H,5H-pyrano[3,2-c]chromene-3-carbonitrile (ACLPh-PC-3-CN), was employed as a chelating modifier for the electrochemical determination of Cd(II) in water samples. ACLPh-PC-3-CN was co-immobilized with Nafion on a glassy carbon electrode to form a stable ACLPh-PC-3-CN/Nafion film that combines ligand-based coordination with cation-exchange-assisted preconcentration of Cd²⁺ at the electrode surface. The Cd(II) response at the modified electrode was characterized by cyclic voltammetry and differential pulse anodic stripping voltammetry, and the data support a predominantly 1:1 Cd(II)–ligand interaction at the interface under the selected conditions. At an optimized pH of 6.0, the sensor provided a linear calibration range from 16.21 to 56.72 μM, with a detection limit of 0.60 μM and a quantification limit of 2.0 μM, and showed good precision (repeatability 2.3% RSD, reproducibility 3.1% RSD) and short-term stability (94% of the initial response after 14 days). The ACLPh-PC-3-CN/Nafion-modified electrode tolerated common inorganic ions and surfactant species (≤5% signal change) and was successfully applied to the determination of Cd(II) in tap water and Red Sea water, affording recoveries between 98.7% and 101%. While the current detection limit is higher than typical guideline values for Cd in drinking water, the proposed sensor compares favorably with several reported electrochemical Cd(II) sensors in terms of simplicity, precision, and matrix tolerance, and represents a useful platform for coordination-based electrochemical sensing of cadmium in environmental water samples. Full article

The housing sector in major cities is facing escalating challenges due to rapid population growth and land scarcity. Consequently, vertical growth has been adopted as a strategic solution to optimize land use while balancing economic, social, and environmental needs. This study examines the phenomenon of vertical growth of the Dammam Metropolitan Area (DMA) in Saudi Arabia, from an urban sustainability perspective, focusing on evaluating the current state of multi-story buildings, their determinants, and their impact on quality of life and infrastructure efficiency. This study utilizes a systematic review methodology and a conceptual approach to develop an integrated framework for sustainable vertical growth. Furthermore, an empirical validation was conducted by projecting this framework onto vertical housing projects in Dammam, focusing on challenges related to design, construction quality, shared service management, and the suitability of apartments for family needs. The results indicate that the shift toward vertical growth achieves land-use efficiency, limits random horizontal expansion, and provides economic opportunities. However, it faces social and cultural constraints, most notably the resistance of some families to changing traditional ownership patterns, limited privacy and green spaces, and challenges in building maintenance and operations. The study highlights the importance of integrating urban planning, governance, architectural design, and infrastructure to ensure the sustainability of vertical growth and provide suitable housing alternatives. The study recommends further field research to assess social acceptance, improve quality-of-life indicators, and develop policies encouraging sustainable vertical expansion in alignment with Saudi Vision 2030 and the 2030 Sustainable Development Goals (SDGs), ensuring cities are more resilient, efficient, sustainable, and liveable. Full article

This study was conducted to investigate a novel quaternary hybrid nanocomposite (QHNC) that can successfully remove Mn(VII) ions from contaminated water. The nanocomposite was analyzed using FTIR, XRD, BET, TGA/DTG and FESEM/EDX techniques to investigate whether the synthesis led to an outcome with optimal properties that will enable it to effectively remove Mn ions from aqueous solutions. Optimal results have been achieved by conducting the analysis at a pH level of 2, using 25 mg of the adsorbent material, an interaction time of 60 min and a concentration of 500 mg/L. The Freundlich isotherm best described the adsorption equilibrium. Further analysis through advanced computational simulations indicated that a sorption process underpins the phenomenon based upon a complex geometry mechanism with a preferential horizontal to inclined orientation of the adsorbate upon the surface. The techno-economic assessment reveals the biosorbent’s viability—with a production cost that is highly competitive at USD 9.95/kg, yet with a stable removal efficiency of nearly 60% over five cycles. Such factors lead to a treatment cost of around USD 7.3 for 1 m³ of 500 mg/L Mn(VII)—confirming both the economic viability and scalability for advanced tertiary wastewater remediation applications. Full article

This study investigates the key determinants of bank stability and profitability in commercial and Islamic banks listed on the Amman Stock Exchange (ASE) in Jordan, with a focus on credit risk and capital adequacy during the period 2018–2024. Using panel data from 15 banks, the study applies fixed effects regression models with clustered standard errors. Liquidity is proxied by the loan-to-deposit ratio (LDR), credit risk by the loans loss provisions-to-total loans ratio, and capital strength by the equity-to-assets ratio, alongside a COVID-19 dummy and an interaction term between liquidity and credit risk. Financial performance and stability are measured using return on assets (ROA), return on equity (ROE), and the logarithmic Z-score. The findings indicate that credit risk has a significant negative effect on both bank performance and financial stability, whereas capital adequacy exerts a positive and significant effect. The COVID-19 pandemic negatively affected financial performance and stability, while liquidity (LDR) shows no significant direct effect. The interaction between liquidity and credit risk was statistically insignificant across all estimated models, suggesting that credit risk remains the dominant determinant regardless of liquidity conditions. The study highlights the importance of effective credit risk management and strong capital buffers in enhancing bank resilience. It contributes to the literature by providing recent evidence from the Jordanian banking sector and by incorporating multiple performance measures, a pandemic shock variable, and risk interaction effects to better understand bank stability within a unified empirical framework for an emerging banking market. Full article