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Governance legitimacy in the oligarchized settings:the case of Bulgaria
No full textOver the past decade, concerns about a crisis of democratic legitimacy have become central in political science scholarship, often linked to the rise of populism, governance transformation, and declining trust in political institutions. This dissertation contributes to these debates by examining how political legitimacy is constructed in contemporary democracies. It conceptualizes legitimacy as a relational, subjective, and processual phenomenon that is continuously produced through practices of legitimation and delegitimation. It argues that these processes are embedded in the social practice of storytelling, through which narratives structure collective understanding of political reality. Particular attention is paid to the role of metaphors in reinforcing certain interpretations and shaping the prominence of specific narratives.Empirically, the dissertation analyses the Bulgarian socio-political situation during the protests of 2020-2021, focusing on mainstream news media. Based on a quali-quantitative analysis, the study reveals widespread perceptions of governance (il)legitimacy that extend beyond specific governments to politic as a whole. Three interrelated narratives – violated democracy, crisis, and left-behindness – structured this delegitimation, with democratic principles serving as the primary normative benchmark. The analysis further shows that governance illegitimacy was configurated through regimes of multidirectional, agonistic, and disapproving metaphors. These metaphors were built on confrontational, unavailing and inflammatory logic, activating “us versus them” dichotomies and evoking perceptions of insecurity and fear. Overall, the dissertation demonstrates that legitimacy crises are not merely the result of institutional failure or deficient argumentation but emerge from overlapping narrative and metaphorical structures that shape how politics is perceived and evaluated in the public sphere
Solute strengthening strategies to design ductile Zn-alloys:A theoretical and computational study
No full textZinc is widely used in the steel industry as a coating material due to its excellent anticorrosive properties. However, its mechanical properties are still poorly understood. Its hexagonal close-packed crystalline structure leads to highly anisotropic elastic and plastic behavior. The latter arises from large differences in the activation stresses of the available slip systems. The Basal slip system activates readily at low applied shear stress, whereas the second most active system, Pyramidal II, requires stresses approximately an order of magnitude higher, resulting in poor ductility.This thesis aims to design a strategy to modify the relative activation of these slip systems through solute strengthening, with the goal of improving the ductility of zinc. To this end, we develop a multiscale modeling framework to study solute–dislocation interactions in Basal dislocations, starting from ab initio inputs. In addition, we develop a machine-learning interatomic potential that enables molecular dynamics and molecular statics simulations of zinc and, in particular, Pyramidal II dislocations.We assess the effects of various solute elements on the behavior and activation of Basal and Pyramidal II dislocations. Finally, we test the proposed strategy by modeling dislocations in the Zn–Al system, extending the machine-learning interatomic potential to this alloy. The thesis outlines a strategy for the design and further study of new zinc coating compositions, highlighting both the strengths and the limitations of the proposed approach
Impact on Hospital Resource Utilization of Endoluminal Bypass Using the Viabahn Endoprosthesis with Heparin Bioactive Surface Compared With Surgical Femoropopliteal Bypass
Get PDFObjective: To assess the impact of heparin-bonded endoprosthesis compared with femoropopliteal bypass on key hospital resources and revenues up to 1-year follow-up. Design: A 2-arm scenario resource consumption data analysis was modeled based on a multicentre prospective randomized controlled trial. Setting: Six centers in the Netherlands. Participants: A total of 100 patients were assigned to 2 arms (50 each arm). The first arm evaluated endovascular treatment using the heparin-bonded Viabahn endoprosthesis and the second the femoropopliteal bypass. Resource consumption rates were compared between arms. Primary and secondary outcomes measures: Resource consumption rates, including hospital stay for bypass procedure, operating room time, type of anesthesia, number of used (endo)grafts, use of different types of bed locations (vascular ward, medium or intensive care), readmission for wound infections, and reinterventions over a period of 12 months. Results: Endovascular repair used fewer hospital resources, with an overall difference of €149.983. Hospital stay was 118 days less (261 vs 379), including 21 fewer days in medium/intensive care (5 vs 26) and 50 fewer operating room hours (100 vs 150). Fewer patients required general anesthesia (31 vs 39), and there were less surgical site infections (3 vs 12). In the surgical bypass group, there were 18 fewer days of hospital stay related to reinterventions (80 vs 62), and the cost of the devices was €309.996, cheaper. The total monetary difference was € 160.013, in favor of the femoropopliteal bypass (€3.200, per patient). Conclusions: Endovascular repair of the superficial femoral artery reduces the use of valuable hospital resources. Its major limitation is the cost of the devices, which should be balanced against the reduction in peri-procedural morbidity and faster recovery. In the context of shortage of hospital beds, it offers capacity benefits, allowing for the treatment of more patients overall. These benefits may outweigh the fewer reinterventions in the surgical bypass group. Registration: The SuperB Trial was registered in clinicaltrials.gov; NCT-ID: NCT01220245. Clinical Impact: Modeling is a useful technique to predict the impact of treatment modalities on hospital resources and revenue. This study uses real-world data from the SuperB Trial to compare two treatment strategies of superficial femoral artery disease, reflecting actual clinical practice and patient outcomes. The analysis focused on direct costs associated with hospital resources and device usage without considering indirect costs or long-term cost-effectiveness. The analysis showed that endovascular repair reduces the use of valuable hospital resources. Its major limitation is device costs, which should be balanced against the reduction in peri-procedural morbidity and faster recovery. In the context of shortage of hospital beds, it offers capacity benefits, allowing for the treatment of more patients overall.</p
Strongly correlated electronic superconductivity in the noncentrosymmetric Re-Os-based high/medium-entropy alloys
No full textThe class of unconventional superconductors, particularly noncentrosymmetric superconductors, has been highly considered as potential materials for understanding the complex properties of quantum materials. Here, five previously unreported Re3.5Os3.5Ta0.5Hf0.5Nb3, Re3Os3Ta0.5Hf0.5Nb3, Re3.5Os3.5Mo0.5Hf0.5Nb3, Re3.5Os3.5Mo0.5W0.5Nb3, and Re3Os3Mo0.5Hf0.5Nb3 Re-Os-based high/medium-entropy alloys (MEAs-HEAs) with valence electron count ranging from 6.45 to 6.81 were synthesized and investigated using x-ray diffraction, transport, magnetization, and specific heat measurements. Our analyses confirm that all five compounds crystallize in a noncentrosymmetric α-Mn-type structure and exhibit type-II superconductivity with Tc values from 4.20 K to 5.11 K, respectively. Unexpectedly, despite being immersed in an acidic environment for one month, the structures and superconducting properties of HEAs remain stable. Our findings indicate that the Tc increases with an increasing valence electron count in MEAs-HEAs. Furthermore, these noncentrosymmetric α-Mn-type HEA superconductors have large Kadowaki-Woods ratios (KWR), implying the presence of strong electronic correlations.</p
Finerenone and New York Heart Association Functional Class in Heart Failure:The FINEARTS-HF Trial
Get PDFBackground: The NYHA functional classification remains an important and widely used metric in heart failure (HF)-oriented clinical care and research. Objectives: This study aims to evaluate whether the effect of finerenone varies according to NYHA functional class in HF with mildly reduced or preserved ejection fraction. Methods: In this prespecified analysis of the FINEARTS-HF trial, treatment effects of finerenone according to baseline NYHA functional class (II or III/IV) were examined on the primary endpoint (cardiovascular death and total HF events) and key secondary endpoints. Effects of finerenone on change in NYHA functional class were evaluated using ordinal logistic regression. Results: At baseline, 4,146 (69%) and 1,854 (31%) participants were NYHA functional class II and III/IV, respectively. Participants with baseline NYHA functional class III/IV vs II experienced a significantly higher rate of cardiovascular death and total HF events (adjusted rate ratio: 1.28 [95% CI: 1.11-1.46]; P < 0.001). Finerenone consistently reduced the primary endpoint irrespective of baseline NYHA functional class (Pinteraction = 0.54), with greater absolute benefits in NYHA functional class III/IV (absolute rate reduction [ARR]: 4.5 per 100 person-years) vs II (ARR: 2.0 per 100 person-years). Benefits of finerenone on Kansas City Cardiomyopathy Questionnaire–Total Symptom Score at 12 months were consistent irrespective of NYHA functional class (Pinteraction = 0.93). NYHA functional class improved similarly in the finerenone and placebo arms out to 12 months. The safety profile of finerenone was similar among participants with baseline NYHA functional class III/IV vs II. Conclusions: In this FINEARTS-HF analysis, finerenone reduced clinical outcomes and improved patient-reported health status in HF with mildly reduced or preserved ejection fraction irrespective of baseline NYHA functional class.</p
Tribological behavior and thermal stability of sputtered WSTi nanocomposite films from room temperature to 400 °C
No full textBased on enthalpy-induced amorphization strategy, magnetron sputtered WSTi nanocomposite films achieved ultralow coefficients of friction (CoF) and enhanced wear resistance at high temperatures up to 400 °C. The effects of Ti doping concentration, tribo-testing temperature, and thermal stability on the microstructure and tribological properties of WSTi films were systematically investigated. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were employed to analyze the microstructure and surfaces of the composite films after tribo-sliding, while the first-principle calculations elucidated the superior lubrication mechanism. Results indicated that the WSTi film with 19.4 at.% Ti exhibited the lowest CoF (0.07) and wear rate (WR, 4.1 × 10−5 mm3/N·m) at room temperature. Furthermore, the film maintained stable lubrication performance at 400 °C, with a low CoF of 0.2. High-temperature annealing (400 °C and 600 °C) induced partial oxidation of WSTi film to WO₃ and TiO₂, yet the residual WS₂ phase preserved advanced self-lubricity through dynamic reorganization into lubricous layered structure. Density functional theory (DFT) calculations revealed that Ti incorporation increases interlayer spacing and reduces shear strength, facilitating ultralow CoF. This study provided a promising strategy for developing high-temperature adaptive solid lubricants for aerospace industrial applications.</p
Comparison of numerical modeling methods for simulating failure in the in-plane response of unreinforced masonry walls
No full textIn this study, two different numerical methods are used to model the structural behavior and failure mechanisms of unreinforced masonry (URM) walls under in-plane static loading using two simplified micro modelling approaches: The Discrete Finite Element Method (FDEM) and the Applied Element Method (AEM). The FDEM approach, which is implemented in LS-DYNA, models wall as separate deformable blocks interacting through point contacts, enabling detailed analysis of damage progression. The AEM approach, which is implemented in the Extreme Loading for Structures (ELS) software, treats wall elements as rigid parts connected by springs, providing a more computationally efficient and versatile solution. These two methods were compared in terms of accuracy, flexibility and computational cost. Performance of the application of the AEM and FDEM are evaluated with available experimental results of masonry wall under in-plane monotonic loading with micro modelling. Failure mechanism of the wall samples under different levels of axial load were evaluated with FDEM and AEM considering nonlinearity of bricks and brick–mortar bond. The impact of contact properties (FDEM) and spring properties (AEM) on the stiffness and in-plane load-bearing capacity of the wall were examined through a sensitivity analysis. The research used tornado diagrams to evaluate the results of the sensitivity analyses, offering insight into which material parameters should be prioritized in future data collection and testing considering two different numerical approaches. The analysis in the presented work revealed the strengths and weaknesses of each method, with the the AEM demonstrating lower computational cost and faster analysis times, while the FDEM provided detailed results due to its finer mesh. A sensitivity study was conducted to examine the impact of material properties on structural responses. It was found that changes in bond tensile strength, cohesion, and friction angle significantly influenced the progression of damage, leading to a shift between failure mechanisms. These findings highlight the importance of material parameter calibration for accurately predicting the behavior of masonry walls. For practical applications, the impact of variations in the material data on the numerical analysis results of masonry structures using the AEM and the FDEM are demonstrated.</p
Perceptions of care providers on the implementation of an antenatal psychosocial clinical decision support system:the Born in Belgium Professionals platform
No full textBackground: Clinical decision support systems (CDSS) can enhance care processes and clinical outcomes. Adoption depends not only on perceived usefulness but also on contextual human, organisational, and technical factors. Understanding care providers’ perception and how these factors influence adoption is essential for implementing systems that can be embedded in routine perinatal practice. Aim: To examine the real-world adoption (or uptake) of the Born in Belgium Professionals antenatal psychosocial decision-support platform, describing how and why care providers use it and identifying facilitators and barriers to sustained implementation. Methods: A cross-sectional survey of all active users (March–July 2024) captured frequency of use, motivations, and perceptions. Frequent versus non-frequent users were compared with chi-square and Mann–Whitney tests (p < .05). Findings: Of 313 users, 127 responded; most were midwives working in large organisations. About 46% were frequent users. Motivators were the psychosocial questionnaire, continuity of care and preventive benefit. Frequent users more often attended training (64.4% vs 30.9%; p < 0.001), perceived greater patient benefit (median 4.5 vs 4.0; p = .046) and rated the platform's integration in electronic health record (EHR) higher (median 5.5 vs 5.0; p = .002). Non-frequent users cited time pressure and interoperability issues. Discussion: Positive perceptions of benefits, adequate training, and seamless workflow integration promote sustained use. Organisational support and robust interoperability further facilitate uptake, whereas time pressures and suboptimal EHR embedding hinder regular use. Conclusion: Implementation strategies that emphasise training, interoperability, and alignment with existing workflows are essential to optimise adoption of antenatal psychosocial decision-support systems.</p