3,485 research outputs found
Employing pre-stress to generate finite cloaks for antiplane elastic waves
It is shown that nonlinear elastic pre-stress of neo-Hookean hyperelastic
materials can be used as a mechanism to generate finite cloaks and thus render
objects near-invisible to incoming antiplane elastic waves. This approach
appears to negate the requirement for special cloaking metamaterials with
inhomogeneous and anisotropic material properties in this case. These
properties are induced naturally by virtue of the pre-stress. This appears to
provide a mechanism for broadband cloaking since dispersive effects due to
metamaterial microstructure will not arise.Comment: 4 pages, 2 figure
Predictive indicators for revisional surgery in nasal reconstruction after Mohs surgery
Background: Reconstruction of nasal lesions is complex due to the topography, mobile free margins and borders of anatomical subunits. Reconstructive challenges can lead to multiple revisional surgeries to achieve the final aesthetic result. This study aimed to evaluate risk factors and predictors of revisional surgery in patients undergoing reconstruction after Mohs micrographic surgery for nasal tumours. Methods: This was a prospective cohort study from April 2, 2008 to February 26, 2019. The study population included all consecutive patients who underwent Mohs micrographic surgery for nasal skin cancer. Resection and reconstruction of nasal skin cancer was performed by the Mohs team. Results: A total of 988 cases met our study inclusion criteria with 64 (6.5%) cases requiring unplanned surgical revision. Revision rates were highest in the ala (9.0%, p < 0.05) and complex anatomical subunits (16.7%, p < 0.0001). In contrast, revision rates for dorsum lesions were lowest (1.8%, p < 0.001). In terms of reconstructive modalities, local flaps resulted in significantly higher rates of revision when compared to grafts (relative risk, 2.37; 95% CI, 1.15–5.0; p < 0.01). In terms of histological diagnosis, squamous cell carcinoma had significantly higher revision rates when compared to basal cell carcinoma (p < 0.05). Conclusions: To our knowledge, this is the first study to report the risk factors and predictors of revision surgery in patients undergoing MMS for nasal tumours. This study highlights that the reconstructive modality utilised affects the functional and cosmetic outcome of MMS. We note that ala complex subunit lesions, squamous cell carcinoma and flap reconstruction were associated with an increased risk of revision after Mohs reconstruction of nasal lesions. Level of evidence: Level III, risk/prognostic; therapeutic study. Trial registration number: (Ref: PLA-19-20_A03) 04/02/2020
Theory and simulation of ultra-high-temperature ceramics
At Imperial College our group contributes theory and simulation advances to the Materials for Extreme Environments (XMat) project. Our research supports experiment and industry by developing and applying new high-temperature modelling techniques. These techniques are broad-ranging, from CALPHAD and DFT, to interatomic potentials and analytic models. Here we present advances on each approach and re-cover highlights including:
- the release of MEAMfit, the interatomic potential fitting code
- the development of the TU-TILD approach, for fast and full-order anharmonic thermodynamics [1]
- a new first-principles-assisted CALPHAD assessment of ZrC
- analytic models of strain and anharmonicity in carbides and borides
- ab initio prediction of intrinsic defects at ultra-high temperatures
- first principles heat and charge transport predictions for carbides
Further, we summarise ongoing developments from the theory and simulation group, such as on first principles MAX phase thermodynamics
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Digital methodology to implement the ECOUTER engagement process
ECOUTER (Employing COnceptUal schema for policy and Translation Engagement in Research) – French for ‘to listen’ – is a new stakeholder engagement method incorporating existing evidence to help participants draw upon their own knowledge of cognate issues and interact on a topic of shared concern. The results of an ECOUTER can form the basis of recommendations for research, governance, practice and/or policy. This paper describes the development of a digital methodology for the ECOUTER engagement process based on currently available mind mapping freeware software. The implementation of an ECOUTER process tailored to applications within health studies are outlined for both online and face-to-face scenarios. Limitations of the present digital methodology are discussed, highlighting the requirement of a purpose built software for ECOUTER research purposes
Devotional Biology: A Young-age Creationist, College-level, Conceptual Biology Textbook
Devotional Biology is being developed as a one-semester college-level conceptual biology textbook for non-science majors. Except for presenting a survey of organisms and an introduction to organismal anatomy and physiology (typically reserved for a second-semester course), Devotional Biology covers all the major topics of biology presented in secular texts as well as a few others not usually covered at all. Student surveys indicate students believe they learn biology through the Devotional Biology text. At the same time, Devotional Biology presents biology from the perspective of a distinctly biblical worldview—and on surveys, Devotional Biology students believe they improved their appreciation of biology as well. Devotional Biology also focuses on God, and how His attributes are evident in the biological world—and on surveys, Devotional Biology students believe they improved their recognition of God in the creation, their understanding of God, their relationship to God, and their use of the creation in witness to others. Devotional Biology also assumes a young-age creationist interpretation of biology, critiquing the naturalistic perspective of the field in the process—and on surveys, Devotional Biology students believe they grew in their faith and learned to defend their faith. Devotional Biology also includes responsibilities of believers as priests and kings in God’s creation—and on surveys, Devotional Biology students believe they grew in their understanding of their ethical responsibilities, in their worship of God, and in better ruling over the creation
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