Trends Analysis of Graphene Research and Development

Purpose： This study aims to reveal the landscape and trends ofgraphene research in the world by using data from Chemical Abstracts Service （CAS）. Design/methodology/approach： Index data from CAS have been retrieved on 78,756 papers and 23,057 patents on graphene from 1985 to March 2016, and scientometric methods were used to analyze the growth and distribution of R＆D output, topic distribution and evolution, and distribution and evolution of substance properties and roles. Findings： In recent years R＆D in graphene keeps in rapid growth, while China, South Korea and United States are the largest producers in research but China is relatively weak in patent applications in other countries. Research topics in graphene are continuously expanding from mechanical, material, and electrical properties to a diverse range of application areas such as batteries, capacitors, semiconductors, and sensors devices. The roles of emerging substances are increasing in Preparation and Biological Study. More techniques have been included to improve the preparation processes and applications of graphene in various fields. Research limitations： Only data from CAS is used and some R＆D activities solely reported through other channels may be missed. Also more detailed analysis need to be done to reveal the impact of research on development or vice verse, development dynamics among the players, and impact of emerging terms or substance roles on research and technology development. Practical implications： This will provide a valuable reference for scientists and developers, R＆D managers, R＆D policy makers, industrial and business investers to understand the landscape and trends ofgraphene research. Its methodologies can be applied to other fields or with data from other similar sources.Originality/value： The integrative use of indexing data on papers and patents of CAS and the systematic exploration of the distribution trends in output, topics, substance roles are distinctive and insightful.

Large-scale transportation and storage of wood pellets:Investigation of the change in physical properties

The change in physical properties of wood pellets,with a focus on particle size distributions due to pellet breakage and attrition,was studied in a large-scale(∼450 ton/h)transportation system.Critical locations with a high probability of breakage through the whole transportation system were chosen and sampled to study the effect of transportation system design and operation on the mechanical properties of pellets.Bulk density,mechanical durability,moisture content,and particle size distribution of pellets were characterized for each sample.Analysis of variance showed that there were significant differences between the percentages of small particles(<5.6 mm)in the samples taken at different locations,especially at one with a vertical free fall of 7.8 m.On average,this relatively long drop increased the proportion of particles<5.6 mm in the samples from 8.73%to 14.09%,and that of particles<3.15 mm from 4.82%to 9.01%.Moreover,the measurements showed a wide deviation in the mechanical durability values,between a minimum of 90.8%and a maximum of 98.7%,which were not correlated to the sampling points but related to pellet properties.It can be concluded that pellet transportation systems require more dedicated design strategies to prevent breakage and attrition.