318,056 research outputs found
Filamentous phages as building blocks for reconfigurable and hierarchical self-assembly
Filamentous bacteriophages such as fd-like viruses are monodisperse rod-like
colloids that have well defined properties: diameter, length, rigidity, charge
and chirality. Engineering those viruses leads to a library of colloidal rods
which can be used as building blocks for reconfigurable and hierarchical
self-assembly. Their condensation in aqueous solution \th{with additive
polymers which act as depletants to induce} attraction between the rods leads
to a myriad of fluid-like micronic structures ranging from isotropic/nematic
droplets, colloid membranes, achiral membrane seeds, twisted ribbons,
-wall, pores, colloidal skyrmions, M\"obius anchors, scallop membranes to
membrane rafts. Those structures and the way they shape shift not only shed
light on the role of entropy, chiral frustration and topology in soft matter
but it also mimics many structures encountered in different fields of science.
On one hand, filamentous phages being an experimental realization of colloidal
hard rods, their condensation mediated by depletion interactions constitutes a
blueprint for self-assembly of rod-like particles and provides fundamental
foundation for bio- or material oriented applications. On the other hand, the
chiral properties of the viruses restrict the generalities of some results but
vastly broaden the self-assembly possibilities
Reason, causation and compatibility with the phenomena
'Reason, Causation and Compatibility with the Phenomena' strives to give answers to the philosophical problem of the interplay between realism, explanation and experience. This book is a compilation of essays that recollect significant conceptions of rival terms such as determinism and freedom, reason and appearance, power and knowledge. This title discusses the progress made in epistemology and natural philosophy, especially the steps that led from the ancient theory of atomism to the modern quantum theory, and from mathematization to analytic philosophy. Moreover, it provides possible gateways from modern deadlocks of theory either through approaches to consciousness or through historical critique of intellectual authorities.
This work will be of interest to those either researching or studying in colleges and universities, especially in the departments of philosophy, history of science, philosophy of science, philosophy of physics and quantum mechanics, history of ideas and culture. Greek and Latin Literature students and instructors may also find this book to be both a fascinating and valuable point of reference
A single-photon sampling architecture for solid-state imaging
Advances in solid-state technology have enabled the development of silicon
photomultiplier sensor arrays capable of sensing individual photons. Combined
with high-frequency time-to-digital converters (TDCs), this technology opens up
the prospect of sensors capable of recording with high accuracy both the time
and location of each detected photon. Such a capability could lead to
significant improvements in imaging accuracy, especially for applications
operating with low photon fluxes such as LiDAR and positron emission
tomography.
The demands placed on on-chip readout circuitry imposes stringent trade-offs
between fill factor and spatio-temporal resolution, causing many contemporary
designs to severely underutilize the technology's full potential. Concentrating
on the low photon flux setting, this paper leverages results from group testing
and proposes an architecture for a highly efficient readout of pixels using
only a small number of TDCs, thereby also reducing both cost and power
consumption. The design relies on a multiplexing technique based on binary
interconnection matrices. We provide optimized instances of these matrices for
various sensor parameters and give explicit upper and lower bounds on the
number of TDCs required to uniquely decode a given maximum number of
simultaneous photon arrivals.
To illustrate the strength of the proposed architecture, we note a typical
digitization result of a 120x120 photodiode sensor on a 30um x 30um pitch with
a 40ps time resolution and an estimated fill factor of approximately 70%, using
only 161 TDCs. The design guarantees registration and unique recovery of up to
4 simultaneous photon arrivals using a fast decoding algorithm. In a series of
realistic simulations of scintillation events in clinical positron emission
tomography the design was able to recover the spatio-temporal location of 98.6%
of all photons that caused pixel firings.Comment: 24 pages, 3 figures, 5 table
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