Morphological Stability of Carbon Nanotetrahedra Isolated from Carbon Nanotetrahedron/Ribbon Structures

2021 ◽  
Vol 90 (11) ◽  
pp. 115001
Author(s):  
Nao Yamamoto ◽  
Hideo Kohno
Keyword(s):  
Morphological Stability ◽  
Ribbon Structures

scholarly journals The living fossil concept: reply to Turner

2021 ◽  
Vol 36 (2) ◽  
Author(s):  
Scott Lidgard ◽  
Alan C. Love
Keyword(s):  
Complex Problem ◽  
Morphological Stability ◽  
Main Argument ◽  
Geological Time ◽  
Problem Space ◽  
Living Fossil ◽  
Living Fossils ◽  
Tadpole Shrimps ◽  
Evolutionary Stasis

AbstractDespite the iconic roles of coelacanths, cycads, tadpole shrimps, and tuataras as taxa that demonstrate a pattern of morphological stability over geological time, their status as living fossils is contested. We responded to these controversies with a recommendation to rethink the function of the living fossil concept (Lidgard and Love in Bioscience 68:760–770, 2018). Concepts in science do useful work beyond categorizing particular items and we argued that the diverse and sometimes conflicting criteria associated with categorizing items as living fossils represent a complex problem space associated with answering a range of questions related to prolonged evolutionary stasis. Turner (Biol Philos 34:23, 2019) defends the living concept against a variety of recent skeptics, but his criticism of our approach relies on a misreading of our main argument. This misreading is instructive because it brings into view the value of three central themes for rethinking the living fossil concept—the function of concepts in biology outside of categorization, the methodological importance of distinguishing parts and wholes in conceptualizing evolutionary phenomena, and articulating diverse explanatory goals associated with these phenomena.

scholarly journals WASP: a software package for correctly characterizing the topological development of ribbon structures

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zachary Sierzega ◽  
Jeff Wereszczynski ◽  
Chris Prior
Keyword(s):  
Software Package ◽  
Helical Structure ◽  
Optical Tweezer ◽  
Application Software ◽  
Not Given ◽  
Magnetic Flux Ropes ◽  
Additional Information ◽  
Non Local ◽  
Alternative Approaches ◽  
Ribbon Structures

AbstractWe introduce the Writhe Application Software Package (WASP) which can be used to characterisze the topology of ribbon structures, the underlying mathematical model of DNA, Biopolymers, superfluid vorticies, elastic ropes and magnetic flux ropes. This characterization is achieved by the general twist–writhe decomposition of both open and closed ribbons, in particular through a quantity termed the polar writhe. We demonstrate how this decomposition is far more natural and straightforward than artificial closure methods commonly utilized in DNA modelling. In particular, we demonstrate how the decomposition of the polar writhe into local and non-local components distinctly characterizes the local helical structure and knotting/linking of the ribbon. This decomposition provides additional information not given by alternative approaches. As example applications, the WASP routines are used to characterise the evolving topology (writhe) of DNA minicircle and open ended plectoneme formation magnetic/optical tweezer simulations, and it is shown that the decomponsition into local and non-local components is particularly important for the detection of plectonemes. Finally it is demonstrated that a number of well known alternative writhe expressions are actually simplifications of the polar writhe measure.

Influence of a transient hexagonal phase on the microstructure and morphological stability of NiSi films

2009 ◽  
Vol 94 (3) ◽  
pp. 033504 ◽  
Author(s):  
C. Van Bockstael ◽  
K. De Keyser ◽  
R. L. Van Meirhaeghe ◽  
C. Detavernier ◽  
J. L. Jordan-Sweet ◽  
...  
Keyword(s):  
Hexagonal Phase ◽  
Morphological Stability

Morphological stability of strained magnetic films against undulation

2009 ◽  
Vol 105 (1) ◽  
pp. 013534 ◽  
Author(s):  
Cheng-hsin Chiu ◽  
G. P. Leyson
Keyword(s):  
Magnetic Films ◽  
Morphological Stability

scholarly journals Additive Manufacturing of Bulk Nanocrystalline FeNdB Based Permanent Magnets

Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 538
Author(s):  
Dagmar Goll ◽  
Felix Trauter ◽  
Timo Bernthaler ◽  
Jochen Schanz ◽  
Harald Riegel ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Melt Spinning ◽  
Permanent Magnets ◽  
Maximum Energy ◽  
Laser Melting ◽  
Powder Bed ◽  
Melt Pool ◽  
Bulk Nanocrystalline ◽  
Ribbon Structures ◽  
Nanocrystalline Ribbon

Lab scale additive manufacturing of Fe-Nd-B based powders was performed to realize bulk nanocrystalline Fe-Nd-B based permanent magnets. For fabrication a special inert gas process chamber for laser powder bed fusion was used. Inspired by the nanocrystalline ribbon structures, well-known from melt-spinning, the concept was successfully transferred to the additive manufactured parts. For example, for Nd16.5-Pr1.5-Zr2.6-Ti2.5-Co2.2-Fe65.9-B8.8 (excess rare earth (RE) = Nd, Pr; the amount of additives was chosen following Magnequench (MQ) powder composition) a maximum coercivity of µ0Hc = 1.16 T, remanence Jr = 0.58 T and maximum energy density of (BH)max = 62.3 kJ/m3 have been achieved. The most important prerequisite to develop nanocrystalline printed parts with good magnetic properties is to enable rapid solidification during selective laser melting. This is made possible by a shallow melt pool during laser melting. Melt pool depths as low as 20 to 40 µm have been achieved. The printed bulk nanocrystalline Fe-Nd-B based permanent magnets have the potential to realize magnets known so far as polymer bonded magnets without polymer.

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