60 research outputs found
First use of single-crystal diamonds as fission-fragment detector
Single crystal chemical vapor deposited diamond (sCVD) was investigated for its ability to act as Fission fragment detector. In particular we investigated timing and energy resolution for application in a simultaneous time and energy measurement to determine the mass of the detected fission fragment. Previous tests have shown that poly crystalline chemical vapor deposited (pCVD) diamonds provide sufficient timing resolution, but their poor energy resolution did not allow complete separation between very low energy fission fragments, alpha-particles and noise. Our present investigations prove artificial sCVD diamonds to show similar timing resolution as pCVD diamonds close to 100 ps. Improved pulse height resolution allows the unequivocal separation of fission fragments, and the detection efficiency reaches 100%, but remains with about a few percent behind requirements for fragment mass identification. With high-speed digital electronics a timing resolution well below 100 ps is possible. However, the strongly varying quality of the presently available diamond material does not allow application on a sufficiently large scale within reasonable investments
Bullet impacts and built heritage damage 1640–1939
© 2018, The Author(s). Conflict damage to heritage has been thrust into the global spotlight during recent conflict in the Middle East. While the use of social media has heightened and enhanced public awareness of this ‘cultural terrorism’, the occurrence of this type of vandalism is not new. In fact, as this study demonstrates, evidence of the active targeting of sites, as well as collateral damage when heritage is caught in crossfire, is widely visible around Europe and further afield. Using a variety of case studies ranging from the 1640s to the 1930s, we illustrate and quantify the changing impact of ballistics on heritage buildings as weaponry and ammunition have increased in both energy and energy density potential. In the first instance, this study highlights the increasing threats to heritage in conflict areas. Second, it argues for the pressing need to quantify and map damage to the stonework in order to respond to these challenges
Erosion and illegibility of images: ‘beyond the immediacy of the present’
The focus of this special journal issue ‘Erosion and Illegibility of Images’ is to explore the relationship of erosion and visibility through contemporary artistic practices at a moment when everything, as Latour suggests, is smashed to pieces. The essays in this issue deploy the notion of erosion as a conceptual tool in order to explore the shifting and depositing of materials, which is observed both on a formal visual level (the breaking up of the image surface) and a critical revaluation of memory, visibility and artistic tools. From an instrumentalist understanding of tools and material, I set out to explore the impact of a radical restriction and limitation of traditional skills and craftsmanship on the artistic process. While recent research has focused predominantly on art theoretical understandings of ruins, the articles collected here aim to interrogate the relationship between artists, artistic tools and the materials of production in contemporary artistic practice by putting them in conversation with each other and scrutinizing interventions such as ‘preservation’, remaking, retro-recuperations and nostalgia work of several kinds
Prompt fission neutron emission: Problems and challenges
This paper presents some of the challenges ahead of us even after 75 years of the discovery of the fission process and large progress made since then. The focus is on application orientation, which requires improved measurements on fission cross-sections and neutron and γ-ray multiplicities. Experimental possibilities have vastly improved the past decade leading to developments of highly sophisticated detector systems and the use of digital data acquisition and signal processing. The development of innovative fast nuclear reactor technology needs improved respective nuclear data. Advancements in theoretical modelling also require better experimental data. Theory has made progress in calculating fission fragment distributions (i.e. GEF code) as well as prompt neutron and γ-ray emission to catch up with the improved experiments
OLT1177, a beta-sulfonyl nitrile compound, safe in humans, inhibits the NLRP3 inflammasome and reverses the metabolic cost of inflammation
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