다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

We present the science and technology roadmap for graphene, related two-dimensional crystals, and hybrid systems, targeting an evolution in technology, that might lead to impacts and benefits reaching into most areas of society. This roadmap was developed within the framework of the European Graphene Flagship and outlines the main targets and research areas as best understood at the start of this ambitious project. We provide an overview of the key aspects of graphene and related materials (GRMs), ranging from fundamental research challenges to a variety of applications in a large number of sectors, highlighting the steps necessary to take GRMs from a state of raw potential to a point where they might revolutionize multiple industries. We also define an extensive list of acronyms in an effort to standardize the nomenclature in this emerging field.

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Science and technology roadmap for graphene, related two-dimensional crystals, and hybrid systems

Nanoscale hydroxyapatite particles for bone tissue engineering

Metal oxides are the key ingredients for the development of many advanced functional materials and smart devices. Nanostructuring has emerged as one of the best tools to unlock their full potential. Tungsten oxides (WOx) are unique materials that have been rigorously studied for their chromism, photocatalysis, and sensing capabilities. However, they exhibit further important properties and functionalities that have received relatively little attention in the past. This Feature Article presents a general review of nanostructured WOx, their properties, methods of synthesis, and a description of how they can be used in unique ways for different applications. Tungsten oxides (WOx) are unique functional materials that can be obtained in a vast variety of nanostructured forms. This Feature Article presents a comprehensive review on the properties of WOx that goes beyond chromism and photocatalysis, for which they are usually investigated for. This is followed by a survey of their synthesis methods and implementations for different applications.

Nanostructured Tungsten Oxide – Properties, Synthesis, and Applications

Preparation and characterization of hydroxyapatite from eggshell

Fracture toughness and toughening mechanisms in graphene platelet reinforced Si3N4 composites

Silicon nitride + 1 wt% graphene platelet composites were prepared using various graphene platelets (GPLs) as filler. The influence of the addition of GPLs on the microstructure development and on the fracture toughness of Si 3 N 4  + GPLs composites was investigated. The GPLs with thickness from 5 nm to 50 nm are relatively homogeneously distributed in the matrix of all composites, however overlapping/bundle formation of GPLs was found, containing 2–4 platelets as well. The single GPLs and overlapped GPLs are located at the boundaries of Si 3 N 4 , and hinder the grain growth and change the shape of the grains. The fracture toughness was significantly higher for all composites in comparison to the monolithic Si 3 N 4 with the highest value of 9.9 MPa m 0.5 for the composite containing the GPLs with smallest dimension. The main toughening mechanisms originated from the presence of graphene platelets, and responsible for the increase in the fracture toughness values are crack deflection, crack branching and crack bridging.

Microstructure and fracture toughness of Si3N4 + graphene platelet composites

In this study, calcium phosphate based bioceramics have been synthesised by using eggshell derived raw materials and phosphoric acid at different mixing ratios. Development of the elaboration processes has been conducted to gain mono phase hydroxyapatite (HAP). The processing route of calcium phosphate ceramics and the end product characteristics have been found to be influenced by acid/CaO mixing ratio, milling time and heat treatment applied. Calcium phosphate foams resulted at higher acid/CaO mixing ratio with high specific surface area. At higher sintering temperatures, calcium phosphate thin and thick film coatings have been produced by a condensation method. The films contained a mixture of micron size crystals and nanofibrous cover layer. The good adherence of films to the calcium phosphate substrate assured a higher strength for these samples.

http://www.nanotechnology.hu/reprint/JEurCeramSoc_27_1601_Balazsi_egg.pdf

Csaba Balázsi

Papers

Preparation and characterization of hydroxyapatite from eggshell

Fracture toughness and toughening mechanisms in graphene platelet reinforced Si3N4 composites

Microstructure and fracture toughness of Si3N4 + graphene platelet composites

Preparation of calcium–phosphate bioceramics from natural resources

Determination of structural and mechanical properties of multilayer graphene added silicon nitride-based composites