Metrogiprotrans (Russia)

Purpose: To examine the life cycle characteristics of single-point and double-point tram track switches under comparable operational and installation conditions. Methods: An analysis of the volume of fundamental maintenance tasks performed on different switch designs over an identical duration, ensuring adherence to technical operational standards. Results: The findings indicate a reduced maintenance requirement for double-point switches compared to single-point switches within the same observation period, even when subjected to increased operational loads. Practical significance: The practical implications of this research are significant, particularly given the widespread use of single-point switches in Saint Petersburg and other urban tram networks. Establishing the economic viability of maintaining a specific switch design directly influences the overall life cycle cost, thereby providing a basis for evaluating the efficacy of different switch types in the design and operation of tram systems.

O artigo apresenta uma reflexão acerca do conteúdo discutido durante a 1ª edição do evento NER Pergunta: O rádio é racista? promovido pelo Núcleo de Estudos de Rádio (NER), em 19 de novembro de 2024 e transmitido via YouTube. No evento, três radialistas negros e gaúchos (Antônio Carlos Côrtes, Denise Cruz e Renê Almeida) responderam a questionamentos formulados pelos internautas da transmissão. A pesquisa está ancorada a partir da perspectiva do racismo cotidiano de Grada Kilomba (2019) que ocorre de maneira sutil, velada e muitas vezes normalizada, tornando-se um elemento estrutural da sociedade e na Comunicação. O processo metodológico ocorre por meio da decupagem da entrevista com os radialistas, aliada à observação qualitativa dos relatos. A análise das narrativas apresentadas no encontro revela percepções significativas sobre práticas racistas no contexto da radiofonia brasileira e sobretudo gaúcha, discutindo-as à luz do Dia Nacional da Consciência Negra.

This study investigated the effectiveness of using flashcards to improve vocabulary mastery among seventh-grade students at SMP Negeri 2 Kisaran, who have demonstrated limited vocabulary knowledge due to difficulties in memorizing new words. The objective was to enhance students’ vocabulary through the implementation of flashcards as a learning tool. The study employed classroom action research based on the Kemmis and McTaggart model, conducted in two cycles comprising the stages of planning, action, observation, and reflection. A total of 30 students from class VII–7 participated in the study. Data were collected through observations and vocabulary tests. The results revealed a significant improvement in students’ vocabulary mastery, with the average test score increasing from 67.8 (33.3%) in Cycle 1 (categorized as low) to 82.8 (73.3%) in Cycle 2 (categorized as high). These findings indicate that the use of flashcards is an effective strategy for enhancing vocabulary acquisition among junior high school students.

Since the discovery of controlled rotation in soap films under electric fields in 2009, the rotation of suspended liquid films has drawn attention across disciplines. While prior studies identified surface charge as a primary driver—particularly in polar liquids and liquid crystals—our work introduces a new influencing factor: the permittivity of the supporting frame. We show that the frame-to-film permittivity ratio governs the transition between slip and no-slip rotational modes. Using both Particle-Image Velocimetry (PIV) and visual inspection, we characterize these modes. Although PIV offers precise measurements, we demonstrate that the two rotational states can be visually distinguished through their color patterns. Films in no-slip rotation exhibit vivid, colored spiral fringe patterns, while slip modes display steady central patterns. These spiral fringes result from white light interference between the incident wave and the portion transmitted through the film and reflected back from the second surface. When the film’s thickness is below the temporal coherence length of white light, and its geometry resembles a hybrid lens–spiral-phase element, concentric fringes transform into dynamic, colored spirals. We propose that in the no-slip mode, the rotating film behaves as a lens-like spiral-phase object. The observed spiral pattern thus serves as both a qualitative signature and a physical indicator of the no-slip regime. This finding provides an accessible optical method for identifying rotational modes and offers new insights into the interplay between electromechanical forces, geometry, and optical behavior in thin liquid films.

Purpose: To assess the engineering condition of the Sukharny tunnel that is an important element of the operating railway. The paper describes the inspection and verification calculations in accordance with the current regulatory requirements for transport underground structures on Lozovo-Sevastopol railway in the Crimea. Methods: Inspection works were performed on the Sukharny Tunnel including measuring, visual inspection and instrument-aided examination. Results: Based on the results of the survey, the tunnel lining parameters were specified. The lining calculations were then carried out taking into account the specified structural parameters. The range of works performed allowed making important conclusions and recommendations on the technical condition of the tunnel structures. Practical significance: After its opening, the Lozovo-Sevastopol railway connected the city of Simferopol with the central part of Russia, and accelerated the reconstruction of Sevastopol and the Black Sea Fleet after the Crimean War. Currently, the railway is still in operation and it is an important transportation artery connecting the city of Sevastopol with the central part of Russia. In the current geopolitical situation, it is especially important to ensure uninterrupted operation of this artery, which would be difficult without proper technical maintenance of the tunnels on this railway. Therefore, the survey and calculation works conducted, conclusions and recommendations proposed have important practical implications.

This study investigates the role of contingency management in enhancing maritime supply chain resilience to improve port performance in Pakistan, focusing on disruptions such as the COVID-19 pandemic. Using the 4A framework Agility, Adaptability, Alignment, and Ambidexterity this research explores how these capabilities mitigate operational disruptions and improve port efficiency. A quantitative research design was employed, collecting data from 320 professionals in Pakistan's maritime sector through a structured questionnaire. The data was analyzed using SPSS software, employing techniques such as reliability, correlation, and regression analysis. Results demonstrate that agility, alignment, and ambidexterity significantly influence port performance, enhancing responsiveness, stakeholder collaboration, and balance between innovation and operational efficiency. However, adaptability showed an insignificant impact due to rigid infrastructural limitations in the regional context. The study emphasizes the integration of the 4A framework to build resilient supply chains, showcasing its potential to address vulnerabilities exposed during the pandemic. By providing actionable insights, this research contributes to the academic literature and offers practical strategies for strengthening maritime supply chain robustness in developing economies.