bluuebunny/crossref_metadata_2025_split huggingface dataset:
Observational study of Super Typhoon Saola in 2023 when it was close to Hong Kong
Authors: Chan P. W. , Choy C. W. , Chiu Y. Y. , He Junyi 
Published: May 2024

AbstractSuper Typhoon Saola came very close to Hong Kong on 1/2 September 2023, necessitating the issuance of the No. 10 hurricane signal, the highest tropical cyclone warning signal in Hong Kong. While there was widespread damage in Hong Kong, no people were killed in the event with effective early warning. It is rare that a super typhoon comes very close to Hong Kong, and this paper is a part in the series of the documentation of Saola to summarize the interesting observations of Saola near Hong Kong for future reference by weather forecasters.
Simulation of Fluid Flow, Heat Transfer and Particle Transport Inside Open-Cell Foam Filters for Metal Melt Filtration
Authors: Werzner Eric , Mendes Miguel A. A. , Demuth Cornelius , Trimis Dimosthenis , Ray Subhashis 
Published: May 2024

AbstractIn order to develop improved filters for metal melt filtration, different physical phenomena that take place during depth filtration of liquid metals need to be well understood. Due to the difficult accessibility of the process, the harsh process conditions and the randomness of the typically employed ceramic foam filters, representative experimental investigations are extremely difficult to perform and often provide only integral quantities or selective information. This chapter presents a numerical model for simulating the depth filtration of liquid metal at the pore-scale, i.e., fully resolving the complex filter geometry, which can also accurately handle the curved filter walls. In the model, the velocity and pressure distribution of the melt flow is obtained by the lattice-Boltzmann method and the temperature field is calculated using the finite volume method, while the transport and filtration of the inclusions are predicted by solving the equation of motion for particles in a Lagrangian reference frame. In order to obtain a consistent representation of the curved filter walls for both particle transport and fluid flow, the Euclidean distance field of the filter structures is employed. By comprehensive parametric studies, the sensitivity of the filtration process with respect to various geometric parameters and process conditions is investigated. Therefore, geometries of conventionally manufactured filters, acquired from 3D μCT scanning, as well as computer-generated filter structures are considered. Their performance is assessed by evaluating various effective properties, such as the viscous and inertial permeability and the filtration coefficient. The numerical predictions allow to draw conclusions with respect to the dominant physical mechanisms and are compared with those from simplified physical models, which are shown to be sufficiently accurate for the pre-screening of filters. On the basis of the detailed results, suggestions for improved filter geometries are made, depending on the considered filtration process. Further, simplified models for the prediction of the effective thermal conductivity of open-cell foams in presence and absence of radiation are presented and validated using the detailed numerical predictions.
Virtual Prototyping of Metal Melt Filters: A HPC-Based Workflow for Query-Driven Visualization
Authors: Lehmann Henry , Jung Bernhard 
Published: May 2024

AbstractThe advent of additive manufacturing has vastly increased the design space of filters for metal melt filtration. In order assess the large amount of possible filter designs before they are actually manufactured, a virtual prototyping workflow based on HPC simulations is proposed. A major challenge are the large data volumes produced even by single CFD simulations of metal melt flow and even more so by virtual prototyping settings, where a large number of filter designs must be evaluated. The LITE-QA framework addresses the large data problem by providing data management methods supporting both the simulation and the analysis phase: In the HPC environment, simulation data are compressed and indexed. In the analysis phase, search engine-like capabilities allow, e.g., for focused visualizations of filter regions that meet the search queries of the analyst. Building on the LITE-QA framework, a virtual prototyping study involving 84 new filter designs for metal melt filtration is conducted. Statistical analyses and comparative visualizations provide insights into the effects of geometric modifications of a reference design. Promising filter designs are identified where simulation results indicate an improved filtration efficiency, while only having a moderate effect on melt flow pressure. These virtual prototypes are proposed as candidates for further testing as physical prototypes.
Analysis of Detrimental Inclusions in Steel and Aluminum
Authors: Weidner Anja , Wagner Ruben , Seleznev Mikhail , Biermann Horst 
Published: May 2024

AbstractThis chapter presents results on the analysis of nonmetallic as well as intermetallic inclusions within a metal matrix. In both, steel and aluminum matrix these impurities cause detrimental effects during production as well as in service, e.g. under mechanical load. In steel, nonmetallic inclusions originate from the steelmaking process and range in the magnitude of ppm. In recycled aluminum alloys, iron-rich intermetallic phases exhibit a volume fraction in the range of percent caused by insufficient scrap separation. Both types of detrimental inclusions/precipitates were investigated within different materials such as case hardening steel, quenched and tempered steel as well as Al-Si cast alloy. In order to reduce the amount of impurities, the effects of appropriate crucible materials, reactive and active melt filtration and chemical composition of the used materials were studied. Therefore, extensive metallographic investigations on sections were conducted with optical microscopy, manual and automated scanning electron microscopy, focused ion beam preparation and transmission electron microscopy aiming to determine the compositions of inclusions and intermetallic phases. Focusing on the morphology of inclusions and intermetallic phases, experiments with electrolytic and chemical extraction as well as X-ray micro tomography were performed. The gained knowledge can be utilized to improve filtration and reduce volume fraction and size of nonmetallic inclusions and intermetallic phases. This enables the design of long-lasting and safe materials.
A Numerical Investigation of Heat Generation Due to Dissipation in Ultrasonic Fatigue Testing of 42CrMo4 Steel Employing Thermography Data
Authors: Koster Michael , Schmiedel Alexander , Wagner Ruben , Weidner Anja , Biermann Horst , Budnitzki Michael , Sandfeld Stefan 
Published: May 2024

AbstractIn ultrasonic fatigue testing of steels one can observe rapid local heating due to crack initiation and propagation caused by non-metallic inclusions and in addition also an overall heating of the gauge length portion of samples which is attributed to dissipational effects. The computations performed in this study are based on a three-dimensional, fully-coupled linear thermoelastic continuum model, where dissipation is included by employing a volumetric heat source. In the numerical computation the temperature distribution evolution in the geometry of interest is the result of a combination of initial conditions, boundary conditions and the heat source contribution. The heat source function's geometry and intensity are deduced by comparing computed temperature profiles to data obtained experimentally using a thermo-camera. It turns out that the modeling approach, making extensive use of thermography data, yields computational results that are in agreement with the experimental heat evolution, and additionally the amount of heat generated is in agreement with results found in literature.
Fatigue Lives and Damage Mechanisms at Elevated Temperatures of Steel 42CrMo4 in the HCF and VHCF Regime
Authors: Schmiedel Alexander , Kirste Thomas , Morgenstern Roman , Weidner Anja , Biermann Horst 
Published: May 2024

AbstractThis chapter is focused on the fatigue life and damage mechanisms of steel 42CrMo4 in the high cycle fatigue (HCF) and very high cycle fatigue (VHCF) regimes at temperatures up to 773 K. For this purpose, resonance fatigue testing was used at different test frequencies (90 Hz and 20 kHz). The influences of the manufacturing process (wrought or cast condition), as well as the core hardness (various heat treatment conditions), were investigated. Fractographic examinations of the fracture surfaces allowed the analysis of crack-initiating defects. Together with light microscopic observations of the defect distribution, the fatigue mechanisms of the steel 42CrMo4 were investigated at different temperatures (RT, 473 K and 773 K). A short crack model according to Chapetti applied to the present results was used to describe the change in the fatigue damage mechanisms operating at RT/473 K and 773 K, respectively. It is shown that high-temperature fatigue at 773 K was dominated by crack growth, whereas fatigue at RT and 473 K was dominated by crack initiation. These investigations complete the work presented in Chap. 24, in which the influence of nonmetallic inclusions on the ultrasonic fatigue behaviour of steel 42CrMo4 is being analysed at room temperature. The present results provide important insights into the crack-initiating defects and their distributions as they are relevant in typical industrial applications.
Interface Reactions Between the Metal Melt and the Filter Surface Activated by a Spark Plasma Sintering Process
Authors: Salomon Anton , Motylenko Mykhaylo , Thümmler Martin , Rafaja David 
Published: May 2024

AbstractThe reactions between newly developed filter materials and metal melts containing various inclusions were analyzed under laboratory conditions. For the melt production, a Spark Plasma Sintering (SPS) apparatus was utilized. The SPS process provides very high heating rates, which emulate the thermo-shock during a real filtration process, and variable reaction times, which allows to simulate both, short and long filtration processes. The short-time filtration processes are relevant for die-casting, where one ton of a steel passes the filter in approx. 15 s, the long-term ones for continuous casting taking several hours. In the SPS process, the convection of the steel melt is suspended, which makes the interpretation of the interfacial reactions and reaction kinetics more straightforward and trustworthy. Furthermore, the SPS process allows speeding up the reaction diffusion kinetics by using tiny diffusion couples having the form of powder mixtures that contain the metal or alloy and the functional filter material under study. In such samples, the equilibrium state that is suitable for a direct comparison with the results of thermodynamic simulations can be achieved very quickly.
Influence of Reactive Filter Materials on Casting’s Quality in Aluminum Casting
Authors: Fankhänel Beate , Schmid Ekaterina , Stelter Michael 
Published: May 2024

AbstractThis chapter presents the most important results of investigations on reactive filter materials for the purification of aluminum melts. Reactive filter materials were developed with the aim to remove impurities dissolved in the melt, such as hydrogen from liquid aluminum, by means of specific chemical interactions between the molten metal and the filter material. Selected ceramic foam filters, consisting of carbon-free and carbon-bonded ceramics, were used in their uncoated state as well as treated with various coatings. Numerous fundamental studies were carried out to evaluate the applicability of the new filter materials: sessile-drop-experiments, immersion and filtration tests, the metallographic evaluation of the used filters and the metal samples retrieved from these experiments. Interfacial reactions and the purity of the treated melts were determined with the help of these experiments, following microstructural analyses to obtain indications for the filtration properties and the potential chemical reactions between the filter material and the melt. As a result, it was possible to determine that spodumene, LiAl(Si2O6), positively influences the hydrogen porosity of aluminum castings when applied as a reactive filter material. Filtration alone already helps to prevent areas of increased macroporosity by calming the melt flow, but filter materials containing spodumene further affect microporosity in the castings in positive ways.
Applying Design Thinking to Improve Students’ Experience in Online Hospitality Courses
Authors: Berezina Katerina , Mahdavi Rasoul , Talebi Mahsa 
Published: May 2024

AbstractThe purpose of this article is to introduce the design thinking approach and illustrate how it may be used to facilitate an online course redesign by providing a specific example. This article builds on the theoretical foundation of the design thinking literature. It reviews the stages of the design thinking process, namely empathize, define, ideate, prototype, and test. The paper also presents an example of design thinking steps being applied to a graduate online hospitality course. The paper used a survey with both qualitative and quantitative questions to understand student experiences in this course, to identify students’ goals and challenges, and to build student personas. This research presents one of the personas developed for the redesigned course and offers an approach to redesigning the class to improve the learning experience for this persona. The approach presented in this paper may be useful to other instructors, program directors, hospitality and tourism training professionals, and instructional designers.
Glamping as a Bourgeoisie Fantasy: The Symbolic Meaning Behind Ritualized Scenes
Authors: Li Qin , Ma Shihan 
Published: May 2024

AbstractCultivating a luxurious ambiance and kindling a bourgeois fantasy of a high-quality lifestyle, glamping has increasingly been viewed a consumption ritual. The purpose of this study is to dig deeper into the composition of ritual scenes in glamping and the symbolic meaning behind them. We obtained 3,176 text reviews and 22,379 photos from Ctrip. Utilizing visual identification and textual mining, this study revealed three categories of ritual scenes in glamping (environmental, activity, and equipment), and four types of ritual symbolism (self-renewal, self-participation, self-presentation, and social connection). The findings highlight that glamping goes beyond simple enjoyment and becomes a way for customers to build social networks and claim a bourgeoisie-lifestyle identity.
How Distinct and Aligned with UGC is European Capitals’ DMO Branding on Instagram?
Authors: Nixon Lyndon J. B. 
Published: May 2024

AbstractDestination positioning refers to destinations identifying their most distinct attributes and focusing on these in their marketing activities in order to distinguish themselves from competitors, develop a brand identity and highlight uniqueness. In this paper, we consider 9 European capitals and analyse their visual marketing on Instagram to identify how truly distinct their destinations are being presented online. By comparing between them as well as comparing to the perceived destination image measured from visitor photos on the same platform, we present a methodology for identifying each destinations distinct attributes and measuring how well DMOs are positioning themselves with respect to competing destinations, with recommendations for improving their positioning.
ChatGPT as a Travel Itinerary Planner
Authors: Volchek Katerina , Ivanov Stanislav 
Published: May 2024

AbstractGenerative AI has become a disruptive force for the Tourism industry. While its potential for generating unique content has been acknowledged, its feasibility for tourists remains unclear. This paper analyses ChatGPT as an itinerary planner. It compares ChatGPT-generated itineraries for 3 destinations with those developed by tourism experts. The evaluation of 11 quality criteria demonstrates that ChatGPT creates easy-to-understand and accessible but less accurate and less specific itineraries. It is a good starting point for travel inspiration. However, it currently cannot serve as an exclusive tool for trip planning.
The Complex World of Online Reviews: Criteria for Establishing a Global Index for Accommodation
Authors: Mellinas Juan Pedro , Martin-Fuentes Eva 
Published: May 2024

AbstractOnline reviews play a crucial role in shaping consumer decisions, particularly in the hospitality industry where the intangibility of services creates uncertainty. The lack of a standardized approach to measure the quality of hotels based on online reviews poses challenges for consumers and businesses alike. In the past, there have been various attempts to create a global index of average accommodation scores. However, all of them presented serious deficiencies in terms of transparency and level of dissemination, failing to achieve the expected success. To address these challenges, the study proposes the establishment of a rational reputation standard for accommodation services through online reviews. A Delphi method is proposed to seek consensus among academic experts and hotel managers, aiming to prioritize criteria for creating a transparent algorithm and a reliable global index for comparing accommodation establishments. The proposed rational reputation standard aims to empower consumers, allowing them to make informed decisions, while benefiting the hospitality industry by promoting transparency and credibility, as well as to allow public authorities with knowledge to establish a quality standard based on online reviews.
Authentication of SMIs by Culturally Different Audiences: Investigation with Chat GPT-3 Prompt Engineering
Authors: Stepchenkova Svetlana , Kirilenko Andrei , Yang Jing 
Published: May 2024

AbstractThis study investigates how online users from culturally different audiences authenticate social media influencers (SMIs) and their creative products which promote destination culture, traditions, and heritage. We specifically examined the theme of existential authenticity focusing on an elevated sense of being, self-reflection, personal discovery, and a sense of community. The context of the study was Chinese influencer Li Ziqi and her videos that depict domestic, day-to-day life in rural areas of the Sichuan province of China. The videos indirectly and organically promote tourism by contributing to more developed perceptions of China’s destinations, people, and the country's brand through building positive associations, which potentially can be leveraged by the DMOs in their marketing efforts.
Varying Roles of Destination Management Organizations in the Digital Business Ecosystem of Tourist Destinations
Authors: Herasimovich Volha , Alzua-Sorzabal Aurkene , Guereño-Omil Basagaitz , Thiel-Ellul Daniela 
Published: May 2024

AbstractUnderstanding the varying roles of Destination Management Organizations (DMOs) in shaping the digital ecosystem is needed in the management and governance of tourist destinations. However, the evaluation is intricate, needing extensive resources to analyze data from numerous stakeholders. This research uses the Digital Business Ecosystem (DBE) framework, hyperlink network analysis, and webometrics to address the complexities. The study examines DMOs’ roles in Gipuzkoa province, Spain, spotlighting its capital San Sebastian recognized as a Smart Destination. It scrutinizes connections of DMOs’ websites alongside websites of other tourism actors (N = 670) and more than 36,000 websites connected to the destination stakeholders’ network. DMOs have distinct roles in the DBE compared to other tourism sectors, with differences evident among DMO types. DMOs play connecting and mediating roles in destination, strengthening network ties and bridging various stakeholders. The study emphasizes the value of varying DMO connections for attracting website visitors. Future research should explore destinations with diverse tech adoption levels and digital transition strategies, while further categorizing stakeholders in the DBE and identifying various ICT actors and their network ties.
Teacher Judgement Accuracy—Measurements, Causes and Effects
Authors: Karing Constance , Rausch Tobias , Artelt Cordula 
Published: May 2024

AbstractThe formation of accurate judgements on students’ performance is often considered as part of teachers’ professional competence. Moreover, inaccurate judgements are seen as determinants of social inequality. Using data of BiKS-8-18 on teacher ratings and student performance, the paper gives an overview on different theoretical approaches and operationalization of judgement accuracy as well as their results in terms of homogeneity, stability over time, inter-individual differences and the effects of judgement accuracy on students’ further achievement. Primary school teachers outperform secondary school teachers in accurately assessing student performance. Furthermore, judgement accuracy did not show to be a general ability. Applying to different student characteristics, however, related to subject areas/domains it proofed to be a relatively time persistent teacher ability. Teacher judgements are somewhat sensitive to characteristics at the class and student level, although bias related to students’ gender and social status was not found for teachers at secondary level. We found positive effects of teacher judgements on students’ achievement gains, particularly in the domain of reading. Finally, by taking into account an add-on study of teachers’ content related knowledge related to judgements on reading performance, we discuss the findings and further highlight the need to take into account judgement purposes and demands in future research.
Developmental Dynamics and Social Disparities in Early Education-Related Child Development: Results from the BiKS-3-18 Study
Authors: Weinert Sabine , Ebert Susanne 
Published: May 2024

AbstractThe development of domain-specific competencies and the emergence of social disparities start well before school entry. These early developments have been suggested to be highly relevant to later developments, educational pathways, and participation in society. Longitudinal large-scale studies, in particular, provide important insights into relevant individual preconditions, developmental trajectories, and their relation to learning opportunities in different learning environments. Against this background, this paper presents selected results of the longitudinal and interdisciplinary study BiKS-3-18 with a special focus on education-related facets of child development at preschool age, their interrelations, predictive impact, and connection to environmental conditions. In particular, we (1) present results on early emerging individual differences between children, their stability over time, and their relation to children’s socioeconomic family background (SES). (2) With a special focus on language development, we address the impact of child characteristics and the dynamics of early child development by presenting findings (a) on changing developmental relations between working memory and language acquisition and (b) on the interrelations between early child language and children’s social-cognitive, metacognitive, and social-emotional development. (3) Finally, we report findings on the importance of individual differences and SES-related disparities, particularly in the language domain, for later school-related language competencies and school performance.