4,489 research outputs found
Thermocapillary approaches to the deliberate patterning of polymers
No full textThe phenomenon of thermocapillarity, the response of fluids to thermal gradients due to thermal alteration of their surface tension, was first reported over a century ago. Since then, research has focused generally on either the fundamentals or mitigation of this effect during the processing of materials. Only in the past two decades has the deliberate use of thermocapillary forces for the patterning of polymers been actively pursued, either for the ordering of internal structure or the introduction of topographic features. This review seeks to highlight this work and further identify directions for further investigation. In particular, while thermocapillary forces are often inextricably bound to other mechanisms, there are emerging directions in the deliberate coupling of forces to improve the capabilities of each mechanism. Further, the applications of thermocapillary patterning to polymer-nanoparticle composites has recently provided another promising route to active architectures.Peer reviewed
Figure 6 in REVIEW The use of integrative taxonomy in Octocorallia (Cnidaria: Anthozoa): a literature survey
No full textFigure 6. Total author pool and number of taxonomic publications on octocorals per year (2000–2020).Published as part of Kessel, Gustav M., Alderslade, Philip, Bilewitch, Jaret P., Schnabel, Kareen E. & Gardner, Jonathan P. A., 2023, REVIEW The use of integrative taxonomy in Octocorallia (Cnidaria: Anthozoa): a literature survey, pp. 677-690 in Zoological Journal of the Linnean Society 198 (2) on page 684, DOI: 10.1093/zoolinnean/zlac099, http://zenodo.org/record/800487
Focused Laser-Induced Marangoni Dewetting for Patterning Polymer Thin Films
No full textHighly-localized focused laser spike (FLaSk) heating of polymer thin films is a resist- and developer-free alternative to 2D laser direct write for creating patterns on the single micron or, by exploiting overlap effects, submicron scale. The massive temporal and spatial thermal gradients and resulting thermal Marangoni stresses generated by FLaSk are an effective means for the directed dewetting and patterning of such films. Here, the general applicability of this technique to glassy amorphous polymer thin film systems is investigated through systematic investigation of film thickness, glass transition temperature, and polymer mobility. The results reveal that the important parameters are the film thickness (coupled to the optical heating effects through anti-reflection coating effects) and the high-temperature polymer melt mobility, allowing for generation of single features with linewidths of down to ~1 μm. Further, the introduction of spatial mobility variations by using polymer brushes, bilayers, and microphase separated block copolymers leads to additional profile manipulation effects (i.e. spontaneous 2D pattern generation and flattened top profiles).Peer reviewe
On the Douglas-Rachford splitting method and the proximal point algorithm for maximal monotone operators
No full textCover title. "This paper consists mainly of dissertation research results of the first author."--Cover.Includes bibliographical references (p. 31-34).Research supported in part by the Army Research Office. DAAL03-86-K-0171 Research supported in part by the National Science Foundation. ECS-8519058by Jonathan Eckstein, Dimitri P. Bertsekas
Figure 1 in REVIEW The use of integrative taxonomy in Octocorallia (Cnidaria: Anthozoa): a literature survey
No full textFigure 1. Number of new octocoral species descriptions per year, 1755–2020.Published as part of Kessel, Gustav M., Alderslade, Philip, Bilewitch, Jaret P., Schnabel, Kareen E. & Gardner, Jonathan P. A., 2023, REVIEW The use of integrative taxonomy in Octocorallia (Cnidaria: Anthozoa): a literature survey, pp. 677-690 in Zoological Journal of the Linnean Society 198 (2) on page 679, DOI: 10.1093/zoolinnean/zlac099, http://zenodo.org/record/800487
The behavioural wedge
No full textWhen nations fail to agree, can individual citizens make a difference? The third of our post-Copenhagen features is by Jonathan Gilligan, Thomas Dietz, Gerald T. Gardner, Paul C. Stern , and Michael P. Vandenbergh . They look at the effects that voluntary actions by individuals can have, and at the policies that can best encourage such actions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79202/1/j.1740-9713.2010.00405.x.pd
The Behavioral Wedge: Reducing Greenhouse Gas by Individuals and Households
No full textWhen nations fail to agree, can individual citizens make a difference? The third of our post-Copenhagen features is by Jonathan Gilligan, Thomas Dietz, Gerald T. Gardner , Paul C. Stern, and Michael P. Vandenbergh. They look at the effects that voluntary actions by individuals can have, and at the policies that can best encourage such actions
Determination of critical cooling rates in metallic glass forming alloy libraries through laser spike annealing
No full textThe glass forming ability (GFA) of metallic glasses (MGs) is quantified by the critical cooling rate (RC). Despite its key role in MG research, experimental challenges have limited measured RC to a minute fraction of known glass formers. We present a combinatorial approach to directly measure RC for large compositional ranges. This is realized through the use of compositionally-graded alloy libraries, which were photo-thermally heated by scanning laser spike annealing of an absorbing layer, then melted and cooled at various rates. Coupled with X-ray diffraction mapping, GFA is determined from direct RC measurements. We exemplify this technique for the Au-Cu-Si system, where we identify Au56Cu27Si17 as the alloy with the highest GFA. In general, this method enables measurements of RC over large compositional areas, which is powerful for materials discovery and, when correlating with chemistry and other properties, for a deeper understanding of MG formation.Peer reviewe
Multiscale Patterning of a Metallic Glass using Sacrificial Imprint Lithography
No full textBulk metallic glasses have been advanced as a means to achieve durable multiscale, nanotextured surfaces with desirable properties dictated by topography for a multitude of applications. One barrier to this achievement is the lack of a bridging technique between macroscale thermoplastic forming and nanoimprint lithography, which arises from the difficulty and cost of generating controlled nanostructures on complex geometries using conventional top-down approaches. This difficulty is compounded by the necessary destruction of any resulting reentrant structures during rigid demolding. We have developed a generalized method to overcome this limitation by sacrificial template imprinting using zinc oxide nanostructures. It is established that such structures can be grown inexpensively and quickly with tunable morphologies on a wide variety of substrates out of solution, which we exploit to generate the nanoscale portion of the multiscale pattern through this bottom-up approach. In this way, we achieve metallic structures that simultaneously demonstrate features from the macroscale down to the nanoscale, requiring only the top-down fabrication of macro/microstructured molds. Upon detachment of the formed part from the multiscale molds, the zinc oxide remains embedded in the surface and can be removed by etching in mild conditions to both regenerate the mold and render the surface of the bulk metallic glass nanoporous. The ability to pattern metallic surfaces in a single step on length scales from centimeters down to nanometers is a critical step toward fabricating devices with complex shapes that rely on multiscale topography for their intended functions, such as for biomedical and electrochemical applications.Peer reviewe
Figure 2 in REVIEW The use of integrative taxonomy in Octocorallia (Cnidaria: Anthozoa): a literature survey
No full textFigure 2. Cumulative number of octocoral species, genus and family descriptions per year (1755–2020): A, species and genera; B, families. Note different axis scales for species (primary y-axis in A), genera (secondary y-axis in A) and families (B).Published as part of Kessel, Gustav M., Alderslade, Philip, Bilewitch, Jaret P., Schnabel, Kareen E. & Gardner, Jonathan P. A., 2023, REVIEW The use of integrative taxonomy in Octocorallia (Cnidaria: Anthozoa): a literature survey, pp. 677-690 in Zoological Journal of the Linnean Society 198 (2) on page 680, DOI: 10.1093/zoolinnean/zlac099, http://zenodo.org/record/800487
- …
