We analyze the performance of a planar lens based on realistic negative index material in a generalized geometry. We demonstrate that the conventional superlens design (where the lens is centered between the object and the image) is not optimal from the resolution point of view, develop an analytical expression for...
In this paper we extend the results of the research started by the first author in which Karlin-McGregor diagonalization of certain reversible Markov chains over countably infinite general state spaces by orthogonal polynomials was used to estimate the rate of convergence to a stationary distribution. We use a method of...
We demonstrate time-resolved terahertz transmission ellipsometry of vertically aligned multi-walled carbon nanotubes. The angle-resolved transmission measurements reveal anisotropic characteristics of the terahertz electrodynamics in multi-walled carbon nanotubes. The anisotropy is, however, unexpectedly weak: the ratio of the tube-axis conductivity to the transverse conductivity, sigma[subscript z]/sigma[subscript xy] [similar or equal to]...
A historical record of Pacific Northwest (defined here as west of the Cascade Mountains in Washington and Oregon) heat waves is identified using the U.S. Historical Climate Network, version 2, daily data (1901–2009). Both daytime and nighttime events are examined, defining a heat wave as three consecutive days above the...
This paper discusses issues of importance to designers of media for visually impaired users. The paper considers the influence of human factors on effectiveness of presentation as well as the strengths and weaknesses of tactile, vibrotactile, static pins, haptic, force feedback, and multimodal methods of rendering maps, graphs and models....
We design a commitment device for college students, “Study More Tomorrow,” conduct a randomized controlled trial testing a model of its takeup, and measure its effect on tutoring attendance and grades. The device commits students to attend tutoring if their midterm grade falls below a pre-specified threshold. Unlike other commitment...
Effective storage and release of low-to-moderate temperature thermal energy (e.g. solar thermal or geothermal) could be transformational for applications such as space heating/cooling, domestic hot water, or off-grid cooking. Good candidates for thermal energy storage in this temperature range include latent heat storage (LHS) systems and thermochemical energy storage (TCES)...
Global warming is expected to cause significant changes in the pattern of precipitation minus evaporation (𝑃 − 𝐸), which represents the net flux of water from the atmosphere to the surface or, equivalently, the convergence of moisture transport within the atmosphere. In most global climate model simulations, the pattern of...
Brazil's economic strategy has shifted hesitatingly during the last several decades from one of producer protection to trade competitiveness. Exploiting the variations these shifts have afforded, we use a sequence of decennial agricultural censuses to examine Brazilian policy implications for agricultural competitiveness and efficiency. Total factor productivity is decomposed into...
Lithospheric cracking by remotely applied stresses or thermoelastic stresses has been suggested to be the mechanism responsible for the formation of intraplate volcanic ridges in the Pacific that clearly do not form above fixed hot spots. As part of the Gravity Lineations Intraplate Melting Petrology and Seismic Expedition (GLIMPSE) project...