Drawing behavior and mechanical properties of ultra-high molecular weight polyethylene blends with a linear polyethylene wax

Ultra-high molecular weight polyethylene (UHMWPE; Mw = 103 kg/mol) is blended with a low molecular weight, linear polyethylene (PEwax; Mw = 1 kg/mol) and the solid state drawing behavior and mechanical properties are explored. The results indicate that the low molecular weight polyethylene wax acts as a solvent for the UHMWPE which leads to an improvement in rheological properties and the maximum attainable draw ratio of the blends. The maximum attainable Young's modulus of the drawn films increases with more than a factor 2 without removal of the solvent. Moreover, it is found that the maximum attainable tensile strength of the drawn blends also increases significantly from ∼1 GPa to ∼1.5 GPa upon addition of 60 wt% of the PEwax. Based on these results, a new route is proposed for the processing of highly oriented polyethylene, which has certain characteristics in common with both melt spinning and solution spinning but, in fact, is neither of the two

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical science. © The Author(s) 2019. Published by Oxford University Press