1,816 research outputs found
C.S. Lewis: Reactions from Women
No full textRecounts the experiences of eight women (including the author) who knew C.S. Lewis
C.S. Lewis’s theory of Sehnsucht as a tool for theorizing L.M. Montgomery’s experience of ‘The Flash'
No full textHigh-k fluoropolymers dielectrics for low-bias ambipolar organic light emitting transistors (Olets)
No full textFunding Information: Author Contributions: Conceptualization, A.A. and C.S.; methodology, A.A. and C.S.; validation, A.A., K.G.-R., and C.S.; data curation, A.A., K.G.-R., and C.S.; writing—original draft preparation, A.A. and C.S.; writing—review and editing, A.A., K.G.-R., and C.S.; supervision, C.S.; project administration, C.S.; funding acquisition, C.S. All authors have read and agreed to the published ver-sion ofFunding:the manuThescript.authors acknowledge the support from the Academy of Finland Flagship Program (Grant No.: 320167, PREIN) and the Aalto seed funding scheme. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Organic light emitting transistors (OLETs) combine, in the same device, the function of an electrical switch with the capability of generating light under appropriate bias conditions. In this work, we demonstrate how engineering the dielectric layer based on high-k polyvinylidene fluoride (PVDF)-based polymers can lead to a drastic reduction of device driving voltages and the improvement of its optoelectronic properties. We first investigated the morphology and the dielectric response of these polymer dielectrics in terms of polymer (P(VDF-TrFE) and P(VDF-TrFE-CFE)) and solvent content (cyclopentanone, methylethylketone). Implementing these high-k PVDF-based dielectrics enabled low-bias ambipolar organic light emitting transistors, with reduced threshold voltages (<20 V) and enhanced light output (compared to conventional polymer reference), along with an overall improvement of the device efficiency. Further, we preliminary transferred these fluorinated high-k dielectric films onto a plastic substrate to enable flexible light emitting transistors. These findings hold potential for broader exploitation of the OLET platform, where the device can now be driven by commercially available electronics, thus enabling flexible low-bias organic electronic devices.Peer reviewe
Multiplicity results for constrained Neumann problems
No full textBy means of critical point theory on manifolds, we establish the
existence of one, two or three solutions for a constrained Neumann problem driven by the p-Laplacian operator and depending on two real parameters. As a special application, we prove the existence of two nontrivial solutions for an unconstrained Neumann problem with positively homogeneous functions
A Higher-Order Energy Expansion to Two-Dimensional Singularly Neumann Problems
No full textOf concern is the
following singularly perturbed semilinear elliptic problem
\begin{equation*}
\left\{ \begin{array}{c}
\mbox{ in }\\
\mbox{ in and on },
\end{array}
\right.
\end{equation*}
where is a bounded domain in with smooth
boundary , is a small constant and
. Associated with the
above problem is the energy functional defined by
\begin{equation*}
J_{\epsilon}[u]:=\int_{\Omega}\left(\frac{\epsilon^2}{2}{|\nabla
u|}^2 +\frac{1}{2}u^2 -F(u)\right)dx
\end{equation*}
for , where .
Ni and Takagi (\cite{nt1}, \cite{nt2}) proved that for a single
boundary spike solution , the following asymptotic
expansion holds:
\begin{equation*}
(1) \ \ \ \ \ \ \ \ J_{\epsilon}[u_{\epsilon}]=\epsilon^{N}
\left[\frac{1}{2}I[w]-c_1 \epsilon
H(P_{\epsilon})+o(\epsilon)\right],
\end{equation*}
where is the energy of the ground state, is a
generic constant, is the unique local maximum point
of and is the boundary mean
curvature function at . Later,
Wei and Winter (\cite{ww3}, \cite{ww4}) improved the result and
obtained a higher-order expansion of :
\begin{equation*}
(2) \ \ \ \ \ \ J_{\epsilon}[u_{\epsilon}]=\epsilon^{N}
\left[\frac{1}{2}I[\omega]-c_{1} \epsilon
H(P_{\epsilon})+\epsilon^2 [c_2(H(P_\epsilon))^2 +c_{3}
R(P_\epsilon)]+o(\epsilon^2)\right],
\end{equation*}
where and are generic constants and
is the scalar curvature at . However, if , the
scalar curvature is always zero. The expansion (2) is no longer sufficient to distinguish spike locations with same mean curvature.
In this paper, we consider
this case and assume that . Without loss of generality, we may assume that the
boundary near P\in\partial\Om is represented by the graph . Then we have the following higher order expansion of
\begin{equation*}
(3) \ \ \ \ \ J_\epsilon [u_\epsilon]
=\epsilon^N \left[\frac{1}{2}I[w]-c_1
\epsilon H({P_\epsilon})+c_2 \epsilon^2(H({P_\epsilon}))^2 ]
+\epsilon^3
[P(H({P_\epsilon}))+c_3S({P_\epsilon})]+o(\epsilon^3)\right],
\end{equation*}
where H(P_\ep)= \rho_{P_\ep}^{''} (0) is the curvature, is a polynomial,
, , and , , are generic real
constants and S(P_\epsilon)= \rho_{P_\ep}^{(4)} (0). In
particular . Some applications of this expansion are given
COMPORTAMIENTO ASINTÓTICO DE LA ECUACIÓN DE ONDA CON CONDICIÓN DE FRONTERA TIPO NEUMANN, LOCALMENTE DISTRIBUIDA
No full textIn the system (*), with Neumann boundary conditions and locally distributed dissipation; where a (x) ≥ a0 >0 a.e.in ω, ωΩ neighborhood 0f Γ= ∂Ω which is an open problem, see [6], we study the asymptotic behavior.En el sistema, con condiciones de frontera del tipo Neumann y disipación localmente distribuida,...donde a (x) ≥ a0 > 0 c.s. en ω, ω inc_01Ω vecindad de Γ= ∂Ω el cuales un problema abierto, ver [6], se estudia el comportamiento asintótico
Von Neumann Normalisation of a Quantum Random Number Generator
No full textIn this paper we study von Neumann un-biasing normalisation for ideal and real quantum random number generators, operating on finite strings or infinite bit sequences. In the ideal cases one can obtain the desired un-biasing. This relies critically on the independence of the source, a notion we rigorously define for our model. In real cases, affected by imperfections in measurement and hardware, one cannot achieve a
true un-biasing, but, if the bias “drifts sufficiently slowly”, the result can be arbitrarily
close to un-biasing. For infinite sequences, normalisation can both increase or decrease
the (algorithmic) randomness of the generated sequences.
A successful application of von Neumann normalisation—in fact, any un-biasing
transformation—does exactly what it promises, un-biasing, one (among infinitely
many) symptoms of randomness; it will not produce “true” randomness
COMPORTAMIENTO ASINTÓTICO DE LA ECUACIÓN DE ONDA CON CONDICIÓN DE FRONTERA TIPO NEUMANN, LOCALMENTE DISTRIBUIDA
No full textEn el sistema, con condiciones de frontera del tipo Neumann y disipación localmente distribuida,...donde a (x) ≥ a0 > 0 c.s. en ω, ω inc_01Ω vecindad de Γ= ∂Ω el cuales un problema abierto, ver [6], se estudia el comportamiento asintótico.</jats:p
C.S. Lewis: adaptations of life and work
No full textThe author discusses film representations of the life of C.S. Lewis – a famous English Christian writer. She also focuses on adaptations (that include books, television and cinema) of his most famous series The Chronicles of Narnia – series that for already sixty years have been published all over the world
The Nurse of Elfland: Lizzie Endicott and C.S. Lewis
No full textIn Surprised by Joy, C.S. Lewis introduced Lizzie Endicott as the first of two other blessings in his childhood, even before his introduction of Warnie. But apart from his abbreviated 136-word biography, very little is known about the nurse who introduced Lewis to faery tales. Based on the Lewis Family Papers, genealogical research, and personal interviews with Lizzie’s relatives, this article introduces Lizzie to the world of Lewismania. It also suggests various ways in which Lizzie influenced the man and the author that C.S. Lewis became, as well as the mythical worlds he created and Lewis’s anonymous tributes to her
- …
