Iskanje po katalogu digitalne knjižnice

Opis: As musculoskeletal illnesses continue to increase, practical computerised muscle modelling is crucial. This paper addresses this concern by proposing a mathematical model for a dynamic 3D geometrical surface representation of muscles using a Radial Basis Function (RBF) approximation technique. The objective is to obtain a smoother surface while minimising data use, contrasting it from classical polygonal (e.g. triangular) surface mesh models or volumetric (e.g. tetrahedral) mesh models. The paper uses RBF implicit surface description to describe static surface generation and dynamic surface deformations based on its spatial curvature preservation during the deformation. The novel method is tested on multiple data sets, and the experiments show promising results according to the introduced metrics.
Ključne besede: radial basis function, muscle model, gradient decsent, curvature, mean curvature, Gaussian RBF
Objavljeno v DKUM: 26.03.2025; Ogledov: 0; Prenosov: 0
Celotno besedilo (1,94 MB)

Opis: The pandemic of COVID-19 disease has brought many challenges in the field of personal protective equipment. The amount of disposable surgical masks (DSMs) consumed increased dramatically, and much of it was improperly disposed of, i.e., it entered the environment. For this reason, it is crucial to accurately analyze the waste and identify all the hazards it poses. Therefore, in the present work, a DSM was disassembled, and gravimetric analysis of representative DSM waste was performed, along with detailed infrared spectroscopy of the individual parts and in-depth analysis of the waste. Due to the potential water contamination by micro/nanoplastics and also by other harmful components of DSMs generated during the leaching and photodegradation process, the xenon test and toxicity characteristic leaching procedure were used to analyze and evaluate the leaching of micro/nanoplastics. Micro/nanoplastic particles were leached from all five components of the mask in an aqueous medium. Exposed to natural conditions, a DSM loses up to 30% of its mass in just 1 month, while micro/nanoplastic particles are formed by the process of photodegradation. Improperly treated DSMs pose a potential hazardous risk to the environment due to the release of micro/nanoparticles and chloride ion content.
Ključne besede: DSM, micro/nanoparticles, leaching, artificial weathering, environmental pollution
Objavljeno v DKUM: 26.03.2025; Ogledov: 0; Prenosov: 0
Celotno besedilo (3,75 MB)
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Opis: Servitization is often based on technology, with the producer not selling products but rather offering product-related services. While servitization had been steadily gaining interest until relatively recently, a new trend called deservitization, the outsourcing of service provision, has seen a slow uptake in the scientific literature. This work analyses why servitization is not always beneficial. We analyze the effect of product complexity on servitization and deservitization in three Southern European countries. Due to high competition and knowledge leaking, manufacturers of complex products tend to servitize with their own resources, thus avoiding deservitization or outsourcing of service provision. The analysis is performed using two-step OLS regression. The results confirm that the hypotheses and the model are significant and that manufacturers of simple products tend to deservitize, while manufacturers of complex products tend to servitize. Managerial implications refer to alternatives as to when to enter the servitization arena and when it is more beneficial to deservitize.
Ključne besede: servitization, deservitization, manufacturing technology, EMS
Objavljeno v DKUM: 26.03.2025; Ogledov: 0; Prenosov: 0
Celotno besedilo (2,12 MB)
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Opis: This protective clothing design project responds to the urgent need for research into the redesign of personal protective equipment (PPE) isolation gowns, to be more fit for purpose and reusable to enhance the experiences of healthcare workers treating patients with COVID-19 and variants. Funded by the Arts and Humanities Research Council (AHRC) the research addresses the engineering question: “What new materials, design and manufacturing approaches should we start to consider in preparation for pandemics e.g. reusable PPE to replace single use?” The article focuses on the online questionnaire/ survey, its main findings and the ‘participatory clothing design’ methodology which prioritises the lived experiences and expressed needs of healthcare workers wearing disposable and reusable PPE in acute care scenarios. Research methods include literature and gown reviews, selected interviews and survey directed at nurses, to acquire first-hand qualitative data about the impact of current gown design and procurement policies on wearers. Selected results and commentary from the ongoing survey are presented and thematically analysed to inform the development of reusable gowns. Semi-structured interviews with clinical leads and caregivers, as well as responses from users, will be important to integrate expertise in fashion, textile and uniform design, clinical practice, and manufacturing. Further design will be based on a complex design brief that balances the needs of wearers and critical care providers while considering regulations, protection, comfort, sustainability, and cost. This research focuses on enhancing an overlooked area of critical care clothing and the people who wear it while reducing its detrimental impact on the planet.
Ključne besede: zdravstveni delavci, ankete, izolacijske obleke, oblačila za večkratno uporabo, izkušnje uporabnika, kvalitativno raziskovanje, healthcare workers, surveys, isolation gowns, reusable PPE, wearer experience, qualitative research
Objavljeno v DKUM: 26.03.2025; Ogledov: 0; Prenosov: 0
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Opis: Cavitation is the phenomenon of fluid evaporation in hydraulic systems, which occurs due to a pressure drop below the value of the vapor pressure. For numerical modelling of this generally undesirable phenomenon, which is often associated with material damage (erosion), there are various mathematical vapor transfer models that have been validated in the past. There are different approaches to predicting cavitation erosion, which have mostly been experimental in the past. Recently various numerical models have been developed with the development of numerical simulations. They describe the phenomenon of cavitation erosion based on different theoretical considerations, such as Pressure wave hypothesis, Microjet hypothesis, or a combination of both. In the present paper, an analysis of the Schnerr-Sauer transport cavitation model was used, upgraded with an erosive potential energy model based on pressure wave hypothesis for cavitation erosion prediction. The extended numerical model has been applied to the case of a radial divergent test section in three different mathematical formulations. The results of simulation were compared and validated to experimental work performed by other authors. The study shows that the distribution of surface accumulated energy agrees with the experimental results, although certain differences exist between formulations. The applied method appears to be appropriate for further use, and to be extended to materials response modelling in the future.
Ključne besede: kavitacija, erozija, erozivna potencialna energija, numerične simulacije, cavitation, erosion, erosive potential energy, numerical simulation
Objavljeno v DKUM: 26.03.2025; Ogledov: 0; Prenosov: 0
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