87 research outputs found
Sacrificial-Post Templating Method for Block Copolymer Self-Assembly
A sacrificial-post templating method is presented for directing block copolymer self-assembly to form nanostructures consisting of monolayers and bilayers of microdomains. In this approach, the topographical post template is removed after self-assembly and therefore is not incorporated into the final microdomain pattern. Arrays of nanoscale holes of different shapes and symmetries, including mesh structures and perforated lamellae with a bimodal pore size distribution, are produced. The ratio of the pore sizes in the bimodal distributions can be varied via the template pitch, and agrees with predictions of self consistent field theory.Semiconductor Research CorporationFENA CenterSemiconductor Research Corporation. Nanoscale Research InitiativeSingapore-MIT AllianceNational Science Foundation (U.S.)Tokyo Electron LimitedTaiwan Semicondcutor Manufacturing Compan
Multipod structures of lamellae-forming diblock copolymers in three-dimensional confinement spaces: experimental observation and computer simulation
The three-dimensional (3D) confinement effect on the microphase-separated structure of a diblock copolymer was investigated both experimentally and computationally. Block copolymer nanoparticles were prepared by adding a poor solvent into a block copolymer solution and subsequently evaporating the good solvent. The 3D structures of the nanoparticles were quantitatively determined with transmission electron microtomography (TEMT). TEMT observations revealed that various complex structures, including tennis-ball, mushroom-like, and multipod structures, were formed in the 3D confinement. Detailed structural analysis, showed that one block of the diblock copolymer slightly prefers to segregate into the particle surface compared with the other block. The observed structures were further elaborated using cell dynamics computer simulatio
Spinor Bose-Einstein condensates
An overview on the physics of spinor and dipolar Bose-Einstein condensates
(BECs) is given. Mean-field ground states, Bogoliubov spectra, and many-body
ground and excited states of spinor BECs are discussed. Properties of
spin-polarized dipolar BECs and those of spinor-dipolar BECs are reviewed. Some
of the unique features of the vortices in spinor BECs such as fractional
vortices and non-Abelian vortices are delineated. The symmetry of the order
parameter is classified using group theory, and various topological excitations
are investigated based on homotopy theory. Some of the more recent developments
in a spinor BEC are discussed.Comment: To appear in Physics Reports. The PDF file with high resolution
figures is available from the following website:
http://cat.phys.s.u-tokyo.ac.jp/publication/review_of_spinorBEC.pd
Designing antifilarial drug trials using clinical trial simulators
Lymphatic filariasis and onchocerciasis are neglected tropical diseases (NTDs) targeted for elimination by mass (antifilarial) drug administration. These drugs are predominantly active against the microfilarial progeny of adult worms. New drugs or combinations are needed to improve patient therapy and to enhance the effectiveness of interventions in persistent hotspots of transmission. Several therapies and regimens are currently in (pre-)clinical testing. Clinical trial simulators (CTSs) project patient outcomes to inform the design of clinical trials but have not been widely applied to NTDs, where their resource-saving payoffs could be highly beneficial. We demonstrate the utility of CTSs using our individual-based onchocerciasis transmission model (EPIONCHO-IBM) that projects trial outcomes of a hypothetical macrofilaricidal drug. We identify key design decisions that influence the power of clinical trials, including participant eligibility criteria and post-treatment follow-up times for measuring infection indicators. We discuss how CTSs help to inform target product profiles
Recent experimental probes of shear banding
Recent experimental techniques used to investigate shear banding are
reviewed. After recalling the rheological signature of shear-banded flows, we
summarize the various tools for measuring locally the microstructure and the
velocity field under shear. Local velocity measurements using dynamic light
scattering and ultrasound are emphasized. A few results are extracted from
current works to illustrate open questions and directions for future research.Comment: Review paper, 23 pages, 11 figures, 204 reference
Effect of chain architectures on the domain spacing of block copolymers with equivalent segregation degrees
Integration of Density Multiplication in the Formation of Device-Oriented Structures by Directed Assembly of Block Copolymer-Homopolymer Blends
Flow instabilities in rheotens experiments: Analysis of the impacts of the process conditions through neural network modeling
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