다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Titanium Dioxide Nanomaterials: Synthesis, Properties, Modifications, and Applications

The richness of optical and electronic properties of graphene attracts enormous interest. Graphene has high mobility and optical transparency, in addition to flexibility, robustness and environmental stability. So far, the main focus has been on fundamental physics and electronic devices. However, we believe its true potential lies in photonics and optoelectronics, where the combination of its unique optical and electronic properties can be fully exploited, even in the absence of a bandgap, and the linear dispersion of the Dirac electrons enables ultrawideband tunability. The rise of graphene in photonics and optoelectronics is shown by several recent results, ranging from solar cells and light-emitting devices to touch screens, photodetectors and ultrafast lasers. Here we review the state-of-the-art in this emerging field.

/pdf/graphene-photonics-and-optoelectronics-3ddg6ukzcu.pdf

Graphene photonics and optoelectronics

Silver nanoparticles as antimicrobial agent: a case study on E. coli as a model for Gram-negative bacteria

Products of Gaussian noises often emerge as the result of non-linear detection techniques or as parasitic effects, and their proper handling is important in many practical applications, including fluctuation-enhanced sensing, indoor air or environmental quality monitoring, etc. We use Rice’s random phase oscillator formalism to calculate the power density spectra variance for the product of two Gaussian band-limited white noises with zero-mean and the same bandwidth W. The ensuing noise spectrum is found to decrease linearly from zero frequency to 2W, and it is zero for frequencies greater than 2W. Analogous calculations performed for the square of a single Gaussian noise confirm earlier results. The spectrum at non-zero frequencies, and the variance of the square of a noise, is amplified by a factor two as a consequence of correlation effects between frequency products. Our analytic results are corroborated by computer simulations.

/pdf/spectra-for-the-product-of-gaussian-noises-4s9h2qfwfw.pdf

Spectra for the Product of Gaussian Noises

Electrochromic oxide films form the basis of "smart windows", which are of much interest in forthcoming building technology and are able to provide energy efficiency and indoor comfort simultaneously. This paper introduces "smart windows" technology, which now seems ready for large-scale applications. Electrochromics is discussed from the viewpoints of materials, device design, low-cost manufacturing, and applications to buildings as well as some niche products. Finally there are some perspectives on the future role of oxide electrochromics in the built environment.

Oxide-based electrochromics for energy efficient buildings: materials, technologies, testing, and perspectives

We study thermochromism in fiber composites with a view to their possible use for controlling the transmission of luminous and solar radiation. Spectrophotometric measurements of collimated and total transmittance were carried out for quartz fibers in carbon tetrachloride. The collimated transmittance showed a peak structure consistent with index matching. The total transmittance was almost featureless; the integrated luminous and solar transmittance decreased by ~20% as the temperature went from 0 to 35 degrees C if the fiber fraction was ?5 vol %. The optical properties could be reconciled with a four-flux model with parameters obtainable from the Mie theory. Specifically, we treated scattering off cylindrical objects in the Rayleigh- Gans limit.

Temperature-dependent transmittance of luminous and solar radiation for quartz fibers immersed in carbon tetrachloride

Total and diffuse reflectance spectra were measured on Al surfaces covered with electrochromic W oxide films in colored and bleached states. Vector perturbation theory was used for analyzing the spectra. The diffuse reflectance appeared to originate from correlated (uncorrelated) interface roughness when the W oxide film was fully colored (bleached). Assuming partially correlated interfaces led to agreement between experimental and calculated spectra. The use of an electrochromic film appears a promising method to control the relative contributions of the interfaces to the resulting scattering.

Electrochromic control of thin film light scattering

We introduce information-theoretic erasure based on Shannon's binary channel formula. It is pointed out that this type of erasure is a natural energy-dissipation-free way in which information is lost in double-potential-well memories, and it may be the reason why the brain can forget things effortlessly. We also demonstrate a new non-volatile, charge-based memory scheme wherein the erasure can be associated with even negative energy dissipation; this implies that the memory's environment is cooled during information erasure and contradicts Landauer's principle of erasure dissipation. On the other hand, writing new information into the memory always requires positive energy dissipation in our schemes. Finally, we show a simple system where even a classical erasure process yields negative energy dissipation of arbitrarily large energy.

/pdf/zero-and-negative-energy-dissipation-at-information-ekzedrwz2t.pdf

Claes-Göran Granqvist

Papers

Spectra for the Product of Gaussian Noises

Oxide-based electrochromics for energy efficient buildings: materials, technologies, testing, and perspectives

Temperature-dependent transmittance of luminous and solar radiation for quartz fibers immersed in carbon tetrachloride

Electrochromic control of thin film light scattering

Zero and negative energy dissipation at information-theoretic erasure