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In this paper, mechanical properties of the diglycidyl ether of bisphenol A epoxy resin (EP) reinforced with a 20% fiber glass (GF) with layered structure after high temperature aging are studied. Tensile and flexural stress-strain curves of the GF/EP composite after aging tests in the temperature range of 85-145 °C in air were measured. Tensile and flexural strength demonstrate gradual decrease with the increase in the aging temperature. The failure mechanism at the micro scale is studied by the scanning electron microscopy. A separation of the GFs and EP matrix and evident pullout of the GFs are observed. Degradation of the mechanical properties is explained by a cross-linking and chain scission of the initial molecular structure of the composite and decrease in the interfacial adhesion force between GFs and EP matrix caused by oxidation of the EP matrix and difference of the GF and EP coefficients of thermal expansion.
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http://dx.doi.org/10.3390/polym15122734 | DOI Listing |
Nature
September 2025
Institute of Biomechanics and Medical Engineering, Applied Mechanics Laboratory, Department of Engineering Mechanics, Tsinghua University, Beijing, China.
The human stomach features distinct, regionalized functionalities along the anterior-posterior axis. Historically, studies on stomach patterning have used animal models to identify the underlying principles. Recently, human pluripotent stem (hPS)-cell-based gastric organoids for modelling domain-specific development of the fundic and antral epithelium are emerging.
View Article and Find Full Text PDFAcc Chem Res
September 2025
Departamento de Química, Universidad Autónoma Metropolitana-Iztapalapa, Ave. Ferrocarril San Rafael Atlixco 186, Col. Leyes de Reforma 1A sección, Alcaldía Iztapalapa, 09310 Mexico City, Mexico.
ConspectusWhat does the word antioxidant mean? Antioxidants are supposed to be nontoxic, versatile molecules capable of counteracting the damaging effects of oxidative stress (OS). Thus, when evaluating a candidate molecule as an antioxidant, several aspects should be considered. Antioxidants are more than free radical scavengers.
View Article and Find Full Text PDFInorg Chem
September 2025
General Education Center, Qinghai Institute of Technology, Xining 810000, China.
Zirconium disilicide (ZrSi) ceramics have excellent physical and chemical properties and are employed in aerospace, energy, and chemical industries. Currently, the preparation and properties of ZrSi ceramics have been less studied. To comprehensively study the characteristics of ZrSi ceramics, in this study, dense bulk ZrSi ceramic samples are successfully prepared by the high-pressure-high-temperature (HPHT) sintering technique.
View Article and Find Full Text PDFJ Prosthet Dent
September 2025
Full Professor, School of Mechanical Engineering, Universidad Industrial de Santander, Bucaramanga, Colombia. Electronic address:
Statement Of Problem: Although custom temporomandibular joint (TMJ) prostheses manufactured via computer-aided design and manufacturing (CAD-CAM) and produced through 3-dimensional (3D) printing or computer numerical control (CNC) allow for sagittal curvature adjustments in the glenoid fossa, their design remains unregulated by the Food and Drug Administration. Consequently, the geometry is determined largely by the engineer's discretion, with limited biomechanical evidence to guide these decisions. The lack of validation regarding how sagittal curvature influences joint stress distribution under various anatomical and functional conditions represents a gap in current knowledge that warrants investigation.
View Article and Find Full Text PDFSci Justice
September 2025
Department of Police Administration, Daegu University, PO Box 38453, Daegu, South Korea; Department of Policing & Security, Rabdan Academy, PO Box 114646, Abu Dhabi, United Arab Emirates. Electronic address:
Latent fingermark recovery from beverage containers is an important aspect of forensic investigations, yet the influence of substrate properties and beverage temperatures on fingermark development remains understudied. This exploratory study assessed the development and quality of latent fingermarks on disposable beverage cups made of nonporous plastic and semiporous paper using cyanoacrylate (CA) fuming, under conditions approximating a typical café environment. A total of 255 cups (107 plastic, 148 paper) were collected after participants consumed hot and iced beverages in a controlled classroom setting.
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