A very important issue that needs to be solved as simply and correctly as possible is how to establish the thermal performance of phase-changing materials (PCM). The undertaken researches have analyzed the values of the thermal performances of the PCM taking into account the method of finite elements and the experimental research, respectively, based on a modern measurement system that was designed and implemented. Butyl stearate which has been encapsulated through complex coacervation in polymethyl methacrylate has been used as a PCM. Samples were made containing 10%, 20%, 30% and 40% PCM, respectively, within their structure. The research has established that at both the hot plate and the cold plate interface, the evolution of the temperature over time, established by both the finite element method (FEM) and experimental research, are quite close, and the best results have been obtained for the P30 sample. A very important thing observed during the finite element method (FEM) is that the simulated thermal flow variation extends between 2700-3110W/m being small enough not to influence the temperature measurement at the interface of hot or cold plates. Thus, the use of the FEM or the experimental research method can be applied with good results, provided that the correct initial conditions are used in the finite element method and that the experimental research is performed using the best possible apparatus.
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http://dx.doi.org/10.3390/polym12020467 | DOI Listing |
J Orthop Surg Res
January 2025
Department of Orthopedics, Beijing Chaoyang Hospital, Capital Medical University, 8 Gongren Tiyuchang Nanlu, Chaoyang District, Beijing, 100020, China.
Background: Finite element analysis (FEA) could advance the understanding of fracture fixation and guide the choice of surgical treatment. This study aimed to compare two internal fixation methods in the treatment of displaced proximal humeral fracture (PHF) through FEA.
Methods: Three-dimensional FEA model based on the left shoulder joint of a 67-year-old female patient with PHFs and osteoporosis was adopted, in order to analyze the fixation effect and load stress distribution of internal fixation plates with open reduction and intramedullary nails without opening the fracture in the treatment of Neer III-VI PHF.
Sci Rep
January 2025
Department of Oral and Maxillofacial Surgery, University Medical Center Groningen, University of Groningen, Hanzeplein 1, P.O. Box 30.001, 9700 RB, Groningen, The Netherlands.
In cases of large mandibular continuity defects resulting from malignancy resection, the current standard of care involves using patient-specific/custom titanium reconstruction plates along with autogenous grafts (fibula, scapula, or iliac crest segments). However, when grafts are not feasible or desired, only the reconstruction plate is used to bridge the gap. Unfortunately, metal osteosynthesis and reconstruction plates, including titanium, exhibit adverse effects such as stress-shielding and limitations in accurate postoperative irradiation (especially with proton-beam therapy).
View Article and Find Full Text PDFSci Rep
January 2025
School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, 102488, China.
The main advantages of microneedles are precise drug delivery through human skin, minimal tissue damage and painlessness. We conducted structural analysis and skin puncture studies of hollow microneedles using ANSYS for three materials: Hafnium Dioxide (HfO), Polyglycolic acid (PGA) and Polylactic acid (PLA). Firstly, we selected three lengths, three tip diameters and three base diameters to conduct a L(3) orthogonal experiment.
View Article and Find Full Text PDFDent Mater
January 2025
Minnesota Dental Research Center for Biomaterials and Biomechanics, School of Dentistry, University of Minnesota, Minneapolis, MN, USA. Electronic address:
Objective: This study compared the fracture load, stress distribution, and survival probability under cyclic loading of extensively restored teeth treated with multisonic irrigation with those treated with conventional instrumentation, with or without a post.
Methods: Mesial-occlusal-distal cavities were prepared in 30 human mandibular premolars. The teeth were randomly divided into 3 groups of 10 based on the endodontic and restorative procedures: (1) Root canal treatment (RCT) followed by resin composite restoration (control group), (2) RCT followed by a glass fiber post restoration (conventional group), and (3) minimal instrumentation plus multisonic irrigation followed by resin composite restoration (GW group).
Dent Mater
January 2025
Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan, Hubei 430072, China; Wuhan University Shenzhen Research Institute, Shenzhen 518108, China. Electronic address:
Objective: Photopolymerized resin composites are widely used as dental filling materials. However, the shrinkage stress generated during photopolymerization can lead to marginal microcracks and eventual restoration failure. Accurate assessment of the stress evolution in dental restorations, particularly in complex cavity geometries, is critical for improving the performance and longevity of the dental filling materials.
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