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Amorphous–amorphous transformations under pressure are generally explained by changes in the local structure from low- to higher-fold coordinated polyhedra 1 – 4 . However, as the notion of scale invariance at the critical thresholds has not been addressed, it is still unclear whether these transformations behave similarly to true phase transitions in related crystals and liquids. Here we report ab initio-based calculations of compressed silica (SiO 2 ) glasses, showing that the structural changes from low- to high-density amorphous structures occur through a sequence of percolation transitions. When the pressure is increased to 82 GPa, a series of long-range (‘infinite’) percolating clusters composed of corner- or edge-shared tetrahedra, pentahedra and eventually octahedra emerge at critical pressures and replace the previous ‘phase’ of lower-fold coordinated polyhedra and lower connectivity. This mechanism provides a natural explanation for the well-known mechanical anomaly around 3 GPa, as well as the structural irreversibility beyond 10 GPa, among other features. Some of the amorphous structures that have been discovered mimic those of coesite IV and V crystals reported recently 5 , 6 , highlighting the major role of SiO 5 pentahedron-based polyamorphs in the densification process of vitreous silica. Our results demonstrate that percolation theory provides a robust framework to understand the nature and pathway of amorphous–amorphous transformations and open a new avenue to predict unravelled amorphous solid states and related liquid phases 7 , 8 . Amorphous–amorphous phase transitions in silicon dioxide are shown to proceed through a sequence of percolation transitions, a process that has relevance to a range of important liquid and glassy systems.

Our results were obtained on 24 cases, 12 plastic molds and 12 dissections, examining the relations between the branches of origin of the pulmonary veins, and of their roots and trunks with the corresponding bronchuses and arteries.We assessed the situation of the superior and inferior right pulmonary veins, of the superior, middle and inferior lobes pedicles, together with the general assessment of the right pulmonary pedicles. Same is on the left. We cannot speak of a general sample that applies to the broncho-pulmonary vascular pedicles or to the relations between the pulmonary veins and their branches with broncho-arterial elements, as they are quite varied; they are characteristic of each lung lobe and even segment, being unable to assess standard relations only in the hilum. When variation in number occurs, even into the hilum we may have altered relations. Also is quite common that vascular branches may pass from one lobe to another, as long as the pulmonary fissures are rarely complete.

Our study was performed on 21 cases, of which 12 were plastic casts and 9 were CT reconstruction. We found that, most frequently (68.75% of the cases), the pulmonary veins were formed by two roots, one superior and one inferior. In 28.13% of cases, the pulmonary veins were formed from three roots (superior, middle and inferior) and in only one case the superior right pulmonary vein had five roots. The venous roots confluence to form the corresponding trunk was at a distance of between 0.5-2 cm. The termination of the superior pulmonary veins was on the upper part of the anterior atrial wall, most commonly in its lateral side. The distance between the right pulmonary veins was between 0.4-3 cm. The inferior pulmonary veins ended on the infero-lateral part of the posterior atrial wall. The distance between the left pulmonary veins was 1.2-3.4 cm. Among the variation in number of the pulmonary veins we met: three cases with three right pulmonary veins and one case when the inferior right pulmonary vein joined terminally the inferior left pulmonary vein, forming a single venous trunk. Supplementary pulmonary veins were encountered only on the right; in one case there were two posterior right pulmonary veins (superior and inferior), in the second case were anterior right pulmonary veins (superior and inferior) and in a third case were three veins, superior, middle and inferior

Amorphous-amorphous transformations under pressure are generally explained by changes in the local structure from low- to higher-fold coordinated polyhedra . However, as the notion of scale invariance at the critical thresholds has not been addressed, it is still unclear whether these transformations behave similarly to true phase transitions in related crystals and liquids. Here we report ab initio-based calculations of compressed silica (SiO ) glasses, showing that the structural changes from low- to high-density amorphous structures occur through a sequence of percolation transitions. When the pressure is increased to 82 GPa, a series of long-range ('infinite') percolating clusters composed of corner- or edge-shared tetrahedra, pentahedra and eventually octahedra emerge at critical pressures and replace the previous 'phase' of lower-fold coordinated polyhedra and lower connectivity. This mechanism provides a natural explanation for the well-known mechanical anomaly around 3 GPa, as well as the structural irreversibility beyond 10 GPa, among other features. Some of the amorphous structures that have been discovered mimic those of coesite IV and V crystals reported recently , highlighting the major role of SiO pentahedron-based polyamorphs in the densification process of vitreous silica. Our results demonstrate that percolation theory provides a robust framework to understand the nature and pathway of amorphous-amorphous transformations and open a new avenue to predict unravelled amorphous solid states and related liquid phases .

We have determined the vibrational properties of a sodium tetrasilicate (Na\\(_{2}\\)Si\\(_{4}\\)O\\(_{9}\\)) glass model generated by molecular dynamics simulations. The study has been carried out using a classical valence force fields approach as well as an {\\it ab initio} approach in the framework of the density functional theory. The total and partial vibrational densities of states (VDOS) are presented, as well as some characteristics of the vibrational modes (participation ratios, correlation lengths). For the low-frequency bands below 500 cm\\({}^{-1}\\), we find that the shapes of the two calculated VDOS as well as those of their corresponding partial VDOS are quite similar. For the intermediate- and high-frequency ranges, we observe larger discrepancies between the two calculations. Using the eigenmodes of the dynamical matrix we also calculate the polarized Raman spectra within the bond-polarizability approximation. We find an overall agreement between the calculated parallel polarized (VV) Raman spectra and the corresponding experimental spectrum. Regarding the perpendicular depolarized (VH) Raman spectrum, the comparison of the calculated spectra to the experimental data indicates a need for an adjustment of the VH bond-polarizability parameters.

Studies of models of current flow behaviour in Electrical Impedance Tomography (EIT) have shown that the current density distribution varies extremely rapidly near the edge of the electrodes used in the technique. This behaviour imposes severe restrictions on the numerical techniques used in image reconstruction algorithms. In this paper we have considered a simple two dimensional case and we have shown how the theory of end point/pinch singularities which was developed for studying the anomalous thresholds encountered in elementary particle physics can be used to give a complete description of the analytic structure of the current density near to the edge of the electrodes. As a byproduct of this study it was possible to give a complete description of the Riemann sheet manifold of the eigenfunctions of the logarithmic kernel. These methods can be readily extended to other weakly singular kernels.

This research article presents a case study exploring the motivational impact of a community-driven book fair held in a Romanian public middle school. The initiative, organized at Scoala Gimnaziala “Mihai Viteazul” in Târgoviște, aimed to foster reading engagement by promoting voluntary book donations, student-led organizing teams, and increased literary access. The event spanned three weeks and involved over 1000 students at various levels of participation. A pre- and post-intervention five-item questionnaire was administered to a selected group of 78 students aged 11–14, complemented by systematic classroom observations conducted by educators. Findings indicate significant improvements in students’ intrinsic motivation to read, perceived access to books, and peer-based reading dialogue. These results highlight the potential of school libraries to act as dynamic agents of literacy development through informal and community-based approaches. The study also outlines challenges related to sample size, generalizability, and the reliance on self-reported data, offering suggestions for future longitudinal research. Ultimately, this article contributes to the growing body of literature on school-based reading interventions and supports the evolving role of librarians as facilitators of student agency and participatory literacy culture..

This research article presents a case study exploring the motivational impact of a community-driven book fair held in a Romanian public middle school. The initiative, organized at Scoala Gimnaziala (Mihai Viteazul) in Targoviste, aimed to foster reading engagement by promoting voluntary book donations, student-led organizing teams, and increased literary access. The event spanned three weeks and involved over 1000 students at various levels of participation. A pre- and post-intervention five-item questionnaire was administered to a selected group of 78 students aged 11-14, complemented by systematic classroom observations conducted by educators.

The concept of classroom discipline refers to the various techniques utilized by educators to regulate the conduct and dispositions of pupils throughout the educational experience, with the aim of promoting compliance with institutional standards and fostering a secure, structured, and stimulating milieu conducive to learning. This article investigates the current methodologies and obstacles encountered by modern educational institutions in effectively addressing classroom behavior management. This article examines the perspectives of aspiring and novice educators on the significance of discipline within the classroom setting. It underscores the criticality of effective communication and collaboration among educational institutions, families, and communities in fostering a conducive and inspiring learning atmosphere. This article examines the perspectives of students in the field of education sciences and novice teachers on the origins of inappropriate student behavior and its impact on the educational process within the school setting. Additionally, the article suggests effective strategies and techniques for fostering responsible and appropriate behavior in the classroom. The article underscores the significance of both initial and continuous professional development in effectively managing student behavior, as well as preventing and addressing incidents of school violence.

The paper presents a synthesis of strategies, benefits, and barriers in the integration management systems (IMS) implementation at the organizational level. The research is based on an assessment of 103 papers, 7 books, 12 standards, and 7 sites. The analysis of works aims to highlight the common integration models of several IMS, aspects related to IMS implementation, benefits of IMS implementations, and the nature of integration strategies. The research results present valuable information which can be used by top managers of organizations, certification bodies, and consulting organizations to encourage the implementation of integrated management systems.