To advance the technology of polymer electrolyte membrane fuel cells, material development is at the forefront of research. This is especially true for membrane electrode assembly, where the structuring of its various layers has proven to be directly linked to performance increase. In this study, we investigate the influence of the various ingredients in the cathode catalyst layer, such as ionomer content, catalyst loading and catalyst type, on the oxygen and ion transport using a full parametric analysis. Using two types of catalysts, 40 wt.% Pt/C and 60 wt.% Pt/C with high surface area carbon, the ionomer/carbon content was varied between 0.29-1.67, while varying the Pt loading in the range of 0.05-0.8 mg cm. The optimum ionomer content was found to be dependent on the operating point and condition, as well as catalyst loading and type. The data set provided in this work gives a starting point to further understanding of structured catalyst layers.
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http://dx.doi.org/10.3390/molecules25071523 | DOI Listing |
J Funct Biomater
December 2024
Department of Restorative Dentistry, Graduate School of Dental Medicine, Hokkaido University, Sapporo 060-8586, Japan.
This study investigated the effects of resin composites (RCs) containing surface pre-reacted glass ionomer (S-PRG) filler on the dentin microtensile bond strength (μTBS) of HEMA-free and HEMA-containing universal adhesives (UAs). Water sorption (WS) and solubility (SL), degree of conversion (DC), and ion release were measured. The UAs BeautiBond Xtreme (BBX; 0% HEMA), Modified Adhesive-1 (E-BBX1; 5% HEMA), Modified Adhesive-2 (E-BBX2; 10% HEMA), and two 2-step self-etch adhesives (2-SEAs): FL-BOND II (FBII; with S-PRG filler) and silica-containing adhesive (E-FBII) were used.
View Article and Find Full Text PDFInt J Clin Pediatr Dent
September 2024
Department of Pedodontics and Preventive Dentistry, Yenepoya Dental College and Hospital, Mangaluru, Karnataka, India.
Background: Dental caries remains a significant oral health concern, particularly in young children. With an increasing interest in preventive strategies, pediatric and preventive dentistry research is now more focused on developing newer materials and techniques to coat the primary teeth to prevent the onset of new carious lesions. While traditional preventive measures such as fluoride application and sealants have been effective in reducing caries incidence, there is still a need for innovative approaches.
View Article and Find Full Text PDFObjective: Aim: To evaluate the correlation between the mineral composition of the hard tissues of the teeth and the percentage of defects and loss of various restorative materials in permanent teeth in children living in the lowland and mountainous geographical zones of Transcarpathian region.
Patients And Methods: Materials and Methods: 1050 permanent teeth of different groups filled with different materials were studied. An ultra-microscopic examination by the method of raster electron microscopy was carried out and the mineral composition of the teeth was evaluated.
Background: A complete and thorough understanding of head and neck anatomy by dental hygienists is fundamental for performing successful dental hygiene procedures in all clinical settings. Therefore, the aim of the present study was to assess the opinion of a population of dental hygiene students about the educational methods, their perceptions of the tooth drawing module, and their opinion about the content of Anatomy curriculum in an Italian University.
Material And Methods: A comprehensive survey about was developed and electronically distributed to the dental hygiene students.
Sci Adv
October 2024
Wolfson Department of Chemical Engineering, Technion - Israel Institute of Technology, Haifa 3200003, Israel.
In fuel cells and electrolyzers, suboptimal proton conductivity and its dramatic drop at low humidity remain major drawbacks in proton exchange membranes (PEMs), including current benchmark Nafion. Sustained through-plane (TP) alignment of nanochannels was proposed as a remedy but proved challenging. We report an anisotropic composite PEM, mimicking the water-conductive composite structure of bamboo that meets this challenge.
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